Bryant 288BNV Evolution™ Variable-Speed Heat Pump Service manual

Bryant 288BNV Evolution™ Variable-Speed Heat Pump Service manual
288BNV EVOLUTIONR V VARIABLE SPEED HEAT PUMP
189BNV EVOLUTIONR V VARIABLE SPEED AIR CONDITIONER
WITH PURONr REFRIGERANT
Service Manual
TABLE OF CONTENTS
PAGE
UNIT IDENTIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
REFRIGERANT PIPING LENGTH LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
LONG LINE APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
ELECTRICAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
MAJOR COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5--7
AOC Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Variable Speed Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Electronic Expansion Valve (EXP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Outdoor Fan Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pressure Transducer (SPT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pressure Equalizer Valve (PEV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Outdoor Coil Thermistor (OCT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Suction Thermistor (OST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Discharge Thermistor (ODT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Crankcase Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Time--Delays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
COMMUNICATION AND STATUS FUNCTION LIGHTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
CHECK CHARGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9--13
Service Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14--34
System Communication Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Model Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Status Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Variable Speed Compressor Winding Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Fan Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Brown Out Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
230v Line (Power Disconnect) Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Pressure Switch Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Suction Pressure Transducer (SPT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Temperature Thermistors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Fault Code Action Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Variable Speed Drive LED Location and Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Compressor Power Harness Assembly Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Inverter Assembly with Shield Gasket Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Compressor Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
WIRING DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37--38
REFRIGERATION SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39--43
Refrigerant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Compressor Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Servicing Systems on Roofs With Synthetic Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Brazing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Service Valves and Pump down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Liquid Line Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Suction Line Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Thermostatic Expansion Valve (TXV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
REFRIGERATION SYSTEM REPAIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
UNIT IDENTIFICATION
The unit is identified using a 16 digit model number structure. It is recommended providing the complete 16 digit model number when
ordering replacement parts to insure receiving the correct parts.
MODEL NUMBER NOMENCLATURE -- HEAT PUMP
1
N
2
N
3
N
4
A
5
A/N
6
N
7
N
8
N
9
N
10
A/N
11
A/N
12
N
14
A
2
8
8
B
N
V
0
3
6
0
0
0
A
Product
Family
2=HP
Tier
SEER
Major
Series
B=Puron
Voltage
Variations
Open
Open
Open
Series
N= 208 ---230 ---1
or 208/230 ---1
V = Variable
Speed
0=Not
Defined
0=Not
Defined
0=Not
Defined
A=
Original
Series
8=
8 = 18 SEER
Evolution
Series
Cooling Capacity
MODEL NUMBER NOMENCLATURE -- AIR CONDITIONER
1
N
2
N
3
N
4
A
5
A/N
6
N
7
N
8
N
9
N
10
A/N
11
A/N
12
N
14
A
1
8
9
B
N
V
0
3
6
0
0
0
A
Product
Family
1=AC
Tier
SEER
Major
Series
B=Puron
Voltage
Variations
Open
Open
Open
Series
N= 208 ---230 ---1
or 208/230 ---1
V = Variable
Speed
0=Not
Defined
0=Not
Defined
0=Not
Defined
A=
Original
Series
8=
9 = 19 SEER
Evolution
Series
Cooling Capacity
SERIAL NUMBER NOMENCLATURE
01
06
E
Week of Manufacture
00001
Serial Number
Manufacturing Site
E = Collierville TN
X = Monterrey Mexico
Year of Manufacture
2
REFRIGERANT PIPING LENGTH LIMITATIONS
Maximum Line Lengths:
The maximum allowable total equivalent length varies depending on the vertical separation. See the tables below for allowable lengths
depending on whether the outdoor unit is on the same level, above or below the outdoor unit.
Maximum Line Lengths
Units on equal level
MAXIMUM ACTUAL LENGTH
ft (m)
100 (30.5)
MAXIMUM EQUIVALENT LENGTH{
ft (m)
100 (30.5)
MAXIMUM VERTICAL SEPARATION ft (m)
N/A
100 (30.5)
100 (30.5)
100 (30.5)
Outdoor unit ABOVE
indoor unit
Outdoor unit BELOW
indoor unit
See Table ’Maximum Total Equivalent Length: Outdoor Unit BELOW Indoor Unit’
{ Total equivalent length accounts for losses due to elbows or fitting. See the Long Line Guideline for details.
Maximum Total Equivalent Length{ -- Outdoor Unit BELOW Indoor Unit
Size
Liquid Line
Diameter
w/ TXV
1 ---Ton
2 ---Ton
3 ---Ton
4 ---Ton
5 ---Ton
3/8
3/8
3/8
3/8
3/8
0--- 20
(0 --- 6.1)
100*
100*
100*
100*
100*
AC / HP with Puronr Refrigerant --- Maximum Total Equivalent Length{
Vertical Separation ft (m) Outdoor unit BELOW indoor unit;
21--- 30
31--- 40
41--- 50
51--- 60
61--- 70
(6.4 --- 9.1)
(9.4 --- 12.2)
(12.5 --- 15.2)
(15.5 --- 18.3)
(18.6 --- 21.3)
100*
100*
100*
100*
100*
100*
100*
100*
100*
100*
100*
100*
100*
100*
100*
100*
100*
100*
100
100
100*
100*
100*
100
100
71--- 80
(21.6 --- 24.4)
100*
100*
100*
--- ----- ---
* Maximum actual length not to exceed 100 ft (30.5 m)
{ Total equivalent length accounts for losses due to elbows or fitting.
--- --- = outside acceptable range
LONG LINE APPLICATIONS
Unit is approved for up to 100 ft (30.5 m) equivalent length and vertical separations shown above with no additional accessories.
Longer line set applications are not permitted.
3
SAFETY CONSIDERATIONS
Installation, service, and repair of these units should be attempted
only by trained service technicians familiar with standard service
instruction and training material.
All equipment should be installed in accordance with accepted
practices and unit Installation Instructions, and in compliance with
all national and local codes. Power should be turned off when
servicing or repairing electrical components. Extreme caution
should be observed when troubleshooting electrical components
with power on. Observe all warning notices posted on equipment
and in instructions or manuals.
!
WARNING
ELECTRICAL HAZARD -- HIGH VOLTAGE!
Failure to follow this warning could result in personal injury
or death.
Electrical components may hold charge. DO NOT remove
control box cover for 2 minutes after power has been
removed from unit.
PRIOR TO TOUCHING ELECTRICAL COMPONENTS:
Verify zero (0) voltage at inverter connections shown on
inverter cover.
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing, modifying, or servicing system, main
electrical disconnect switch must be in the OFF position.
There may be more than 1 disconnect switch. Lock out and
tag switch with a suitable warning label.
!
WARNING
EXPLOSION HAZARD
Failure to follow this warning could
result in death, serious personal injury,
and/or property damage.
Never use air or gases containing
oxygen for leak testing or operating
refrigerant compressors. Pressurized
mixtures of air or gases containing
oxygen can lead to an explosion.
!
!
CAUTION
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care and
wear appropriate protective clothing and gloves when
handling parts.
Refrigeration systems contain refrigerant under pressure. Extreme
caution should be observed when handling refrigerants. Wear
safety glasses and gloves to prevent personal injury. During normal
system operations, some components are hot and can cause burns.
Rotating fan blades can cause personal injury. Appropriate safety
considerations are posted throughout this manual where potentially
dangerous techniques are addressed.
If you do not understand any of the warnings, contact your
product distributor for better interpretation of the warnings.
GENERAL INFORMATION
The 288BNV & 189BNV split system heat pump and air
conditioners features a new outdoor cabinet design that uses a
four--sided coil design to minimize the unit footprint and provide
the best heat exchange taking full advantage of the latest variable
speed technology.
The heart of the system is the Toshiba Carrier variable speed rotary
compressor powered through the use of the variable speed drive
(VSD) inverter control. Through the use of Puron refrigerant,
compact ECM outdoor fan motor, VSD and variable speed scroll
compressor, along with the new outdoor cabinet, the unit achieves
a Seasonal Energy Efficiency Ratio (SEER) of up to 19 and up to
11 Heating Seasonal Performance Factor (HSPF).
To ensure ultimate comfort, these units should be combined with
either the FE fan coil or Variable Speed Gas furnace controlled
with a two wire communication Evolution Connex Control
SYSTXBBITC01, SYSTXBBITW01 or SYSTXBBITN01 with
version 11 software or newer. Version 12 software or newer
required for model size 13. This combination will ensure
achievement of comfort with the convenience of fingertip trouble
shooting and diagnostic capability. These units can also use a
standard, 2--stage or single--stage thermostat, for limited
functionality. However, 1--ton models will require the use of an
Evolution Control.
WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could result in personal
injury or equipment damage.
Puronr (R--410A) systems operate at higher pressures than
standard R--22 systems. Do not use R--22 service equipment
or components on Puronr equipment. Ensure service
equipment is rated for Puronr.
4
ELECTRICAL
!
WARNING
MAJOR COMPONENTS
Application Operational Control Board (AOC)
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Exercise extreme caution when working on any electrical
components. Shut off all power to system prior to
troubleshooting. Some troubleshooting techniques require
power to remain on. In these instances, exercise extreme
caution to avoid danger of electrical shock. ONLY TRAINED
SERVICE
PERSONNEL
SHOULD
PERFORM
ELECTRICAL TROUBLESHOOTING.
Aluminum Wire
!
CAUTION
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Aluminum wire may be used in the branch circuit (such as
the circuit between the main and unit disconnect), but only
copper wire may be used between the unit disconnect and the
unit.
Whenever aluminum wire is used in branch circuit wiring with this
unit, adhere to the following recommendations.
Connections must be made in accordance with the National
Electrical Code (NEC), using connectors approved for aluminum
wire. The connectors must be UL approved (marked Al/Cu with
the UL symbol) for the application and wire size. The wire size
selected must have a current capacity not less than that of the
copper wire specified, and must not create a voltage drop between
service panel and unit in excess of 2 of unit rated voltage. To
prepare wire before installing connector, all aluminum wire must
be “brush--scratched” and coated with a corrosion inhibitor such as
Pentrox A. When it is suspected that connection will be exposed to
moisture, it is very important to cover entire connection completely
to prevent an electrochemical action that will cause connection to
fail very quickly. Do not reduce effective size of wire, such as
cutting off strands so that wire will fit a connector. Proper size
connectors should be used. Check all factory and field electrical
connections for tightness. This should also be done after unit has
reached operating temperatures, especially if aluminum conductors
are used.
Unit Electrical Power
Power wires from the unit’s disconnect should be routed through
the power wiring hole provided at the bottom of the unit’s control
box.
Connect the ground wire to the ground connection in the control
box and connect the power wiring to the terminal block as shown
on the wiring and Installation Instructions supplied with the unit.
The unit does not require a contactor or outdoor unit transformer in
order to operate.
A160120
Fig. 1 – AOC (Application Operational Control) Board
The AOC board is located in the lower right hand side of inverter
tray. It’s functions include:
S Compressor speed control
S Outdoor fan motor control
S Reversing valve operation
S Defrost operation
S Crankcase heater operation
S Pressure switch monitoring
S Time Delays
S Pressure Transducer measurements
S PEV control (pressure equalizer valve)
S Temperature measurements
S EXV (Electronic Expansion Valve) operation control
S Inverter communication and control
Inverter
The inverter is located inside the control box. This is an air--cooled
device that communicates with the control board and drives the
compressor and fan motor to the demanded RPM. The inverter is
always powered with line voltage since no contactor is used. The
inverter changes the line voltage to DC volts and then recreates 3
phase sine waves that vary in frequency to drive the compressor
and fan motor at the desired RPM.
NOTE: The unit may be operated with an Evolution Connex
Control or a standard 2--stage HP thermostat. However, 1--ton
models will require the use of an Evolution Control. Evolution
Connex Control will utilize 5 stages of heating and cooling, while
2--stage HP thermostat will only allow 2 discrete stages of heating
and cooling operation.
Variable Speed Compressor
This unit contains a variable speed rotary compressor that has a
wide operating range. It operates on a variable 3 phase sine wave
provided by the inverter. This compressor can only be operated by
the specific inverter supplied with the unit.
5
!
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
and/or improper operation.
Do not attempt to apply line voltage directly to the
compressor. This will destroy the compressor.
Electronic Expansion Valve (EXV)
This unit uses an electronic expansion valve for refrigerant
metering in the heating mode. The control board drives the EXV to
its proper position based on the operating mode and conditions.
The Evolution Connex Control Service mode allows for manual
opening and closing of the EXV for troubleshooting and pump
down.
A14302
Outdoor Fan Motor
Fig. 2 – HP Outdoor Coil Thermistor (OCT) Attachment
(On Distributor Tube)
The compact ECM outdoor fan motor is a variable--speed brushless
DC (BLDC) motor that operates at speeds from 400 to 1050 RPM.
The motor is a 3--phase permanent magnet--type motor. Just like
the compressor, this motor speed is determined by the inverter
output frequency and amplitude.
Motor speed is controlled through the inverter board in the outdoor
unit and no electronic module is attached. Motor speed is slowed as
the building load decreases, maintaining the proper condensing
temperature for both cooling and dehumidification. As the building
load increases, the motor will increase speed until it is at maximum
speed at the maximum building load.
At unit start--up, there is a slight delay and thrust motion of the fan
motor/blade in the reverse direction, prior to ramping--up the fan
assembly.
Pressure Transducer (SPT)
A 5 VDC output low pressure transducer that provides a 0--5 VDC
data for interpretation by the control board for a 0 to 200 psig
range of pressure at the suction tube. This interpreted pressure data
is then intelligently used by the AOC control board for low
pressure cut--out, loss of charge management, compressor
protection, oil circulation management, lubrication management
and EXV control.
A14328
Fig. 3 – AC Outdoor Coil Thermistor (OCT) Attachment
(On Distributor Tube)
Pressure Equalizer Valve (PEV)
OAT Thermistor must be locked in place with
spherical nib end facing towards the front of
the control box
At the end of every compressor operation (after the 3.5 minute
Time Guard period), the equalizer valve opens for 150 seconds
plus an additional 15 seconds of protection before allowing the
compressor to start ramping up.
The PEV is located next to the suction and discharge of the
compressor. The function of this valve is to prevent the
compressor from starting with a high refrigerant pressure
differential, thus helping the reliability of the compressor.
NOTE: A hissing sound may be heard during the equalization
process. This is normal.
Outdoor Coil Thermistor (OCT)
The outdoor coil thermistor is a 10Kohm resistor used for multiple
system operations. It provides the coil/liquid line temperature to
the heat pump board and user interface. Low ambient operation,
defrost initiation, defrost termination and assistance with OAT
temperature measurement of some of the functions (see Fig.4) .
The sensor must be securely mounted to the tube connecting the
EXV and distributor. See Fig. 2 and Fig. 3 for proper placement.
See Table 5 for proper resistances.
A11142
Fig. 4 – OAT Thermistor Location (Bottom of Control Box)
6
Suction Thermistor (OST)
Crankcase Heater Operation
Suction Thermistor is used for assisting in EXV control and must
be secured on the suction tube and aligned longitudinally to the
vertical surface of the tube axis (see Fig. 5).
This unit has an internal crankcase heater that will be energized
during the off cycle and is intelligently demanded by the system to
prevent the compressor from being the coldest part of the system
thus enhancing the reliability. The crankcase heater will function
as needed any time the outdoor unit is powered. The indoor unit
and UI do not need to be installed for the crankcase heater to
operate properly.
The compressor windings will occasionally be energized during
the OFF cycle (depending on the length of the OFF cycle) to start
the stator heat operation, thus maintaining a sump temperature that
is essential for compressor reliability. The compressor will not run
during this process.
!
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
In order to minimize the ambient influence, make sure the
thermistor curved surface hugs the pipe surface and is
secured tight using the wire tie fished through the original
slot insulating polymer body.
Time Delays
The unit time delays include:
S 3.5 minute time delay after last cycle, initial power up, return
from brown--out condition. To bypass this feature, momentarily
short and release Forced Defrost pins.
S At the end of every compressor ON cycle, there will be 150
seconds of PEV open period for pressure equalization followed
by 15 seconds of PEV Off period before the next compressor
ON cycle. This delay cannot be bypassed as it helps compressor
reliability.
S 15 second delay at termination of defrost before the auxiliary
heat is de--energized.
S See Table 6 for other delay information.
S 10 minute sump warm--up delay. This delay is at the beginning
of each high voltage power up.
A14023
Fig. 5 – Suction Thermistor (OST) Attachment
(On Suction Tube)
Discharge Thermistor (ODT)
Discharge Thermistor is used for protection against over
temperature of the compressor. The ODT is located on the
compressor discharge stub--out (see Fig. 6).
A14024
Fig. 6 – Discharge Thermistor (ODT)
7
COMMUNICATION AND STATUS FUNCTION LIGHTS
Evolution Connex Control, Green Communications (COMM)
Light
A green LED (COMM light) on the outdoor board (see Fig. 7 and
8) indicates successful communication with the other system
products. The green LED will remain OFF until communication is
established. Once a valid command is received, the green LED will
turn ON continuously. If no communication is received within 2
minutes, the LED will be turned OFF until the next valid
communication. The green LED will be turned off when using a
standard 2--stage non--communicating heat pump thermostat.
Amber Status Light
Amber colored STATUS light indicates operation and error status.
See Table 6 for definitions.
S Two minute time delay to return to standby operation from last
valid communication.
Defrost
This user interface (UI) offers 4 possible defrost interval times: 30,
60 and 90 minutes, or AUTO. The default is AUTO.
Defrost interval times: 30, 60, and 90 minutes or AUTO are
selected by the Evolution Connex Control User Interface if using
UI. The 90 minute selection will default to 60 minutes at ambient
below 37 degrees. The UI setting will supersede the dip switch
settings on the control board if not the same.
If using non--communicating thermostat, defrost intervals are set
using dip switches on outdoor control board (see Fig. 7 and 8).
AUTO defrosts adjusts the defrost interval time based on the last
defrost time as follows:
Fig. 7 – AOC Control Board for 1 and 2 Ton
S When defrost time <5 minutes, the next defrost interval=90
minutes. (outdoor temperature above 37_F)
S When defrost time 5--7 minutes, the next defrost interval=60
minutes.
S When defrost time >7 minutes, the next defrost interval=30
minutes.
The control board accumulates compressor run time. As the
accumulated run time approaches the selected defrost interval time,
the control board monitors the coil temperature sensor for a defrost
demand. If a defrost demand exists, a defrost cycle will be initiated
at the end of the selected time interval. A defrost demand exists
when the coil temperature is at or below 32_F (0_C) for 4 minutes
during the interval. If the coil temperature does not reach 32_F
(0_C) within the interval, the interval timer will be reset and start
over.
S Upon initial power up the first defrost interval is defaulted to 30
minutes. Remaining intervals are at selected times.
S Defrost is only allowed to occur below 50_F (10_C) outdoor
ambient temperature.
The defrost cycle is terminated as described below.
S When OAT is > 25_F (+3.89_C), defrost terminates if outdoor
coil temperature (OCT) > 60_F (+15.6_C). And a minimum of
one (1) minute defrost length.
S When OAT ≦ 25_F (+3.89_C), defrost will terminate if OCT is
>45_F (+4.4_C) and a minimum of 2 minutes defrost length.
S Or 10 minutes has passed.
At the defrost termination, the outdoor fan will turn on 10 seconds
before the reversing valve switching.
NOTE: Compressor speed during defrost will go to defrost speed.
A150034
Fig. 8 – AOC Control Board for 3, 4 and 5 Ton
8
A14021
CHECK CHARGE
Charge in CHARGING mode (communicating only)
Unit is factory charged for 15ft (4.57 m) of lineset. If any
refrigerant charge adjustment is required due to the user inputted
line set length, the UI will calculate and display the target
subcooling and the amount of additional charge to be added.
Therefore, the UI is your source of information for charging the
system correctly. Refrigerant charge adjustment amount for adding
or removing 0.6 oz/ft (17.74 g/m) of 3/8 liquid line above or below
15ft (4.57 m) respectively. Perform a final charge check only when
in cooling and OD is between 65_F (18_C) and 100_F (38_C).
The use of a commercial charge metering device (restrictor) such as
Imperial liquid low side charger model 535--C or Watsco
ChargeFaster model CH200 is recommended when adding
refrigerant to an operating system. This prevents potential damage
of liquid slugging of the compressor and allows the subcooling to
stabilize quicker.
Charging using the subcooling method optimizes charge volume
and is preferred if possible. If the outdoor temperature is between
65_F -- 100_F (18.3_C -- 37.8_C) and indoor temperature is 70_F
-- 80_F (21.1_C -- 26.7_C), the option to further adjust charge
using “service valve subcool” will be available in the “charging
mode selection” screen. If temperatures are outside of range, this
option will be greyed out and not selectable. Inaccurate charging
may result in nuisance fault codes.
Initial start--up can be performed using calculated charge only and
once conditions are within range, the ”Service Valve Subcool”
option will become selectable.
Once start is selected the system will operate in a preset mode until
“done” is selected. Wait for required stabilization time then check
subcooling at service valve.
Adjust charge as required to meet target service valve subcooling
shown on screen --3/+0 degree. If any adjustment is necessary, add
or remove the charge slowly (no greater than .5 lb per minute) and
allow system to operate for 25 minutes to stabilize, before
declaring a properly charged system.
Fig. 11 – Stabilization Time
Charging Non-- Communicating Systems
Charging Procedure: Force system to operate in high stage
cooling by creating a large differential between room temperature
and set point on thermostat. Use multi--meter to verify that 24
VAC is present between C, Y1 /Y2 terminals at outdoor unit.
Factory charge amount is shown on unit rating plate for high stage.
Target subcooling chart is provided on back of control box door
see Fig. 12 -- 26 for example. To properly check or adjust charge,
condition must be favorable for subcooling charging. Favorable
conditions exists when outdoor temperature is between 65_F
(18_C) and 100_F (38_C), and the indoor temperature is between
70_F (21_C) and 80_F (27_C). Follow the procedure below:
Unit is factory charged for 15ft (4.57 m) of lineset. Adjust charge
by adding or removing 0.6 oz/ft (17.7 g/m) of 3/8 liquid line above
or below 15ft (4.57 m) respectively.
For standard refrigerant line lengths (80ft/24.4 m or less), allow
system to operate in cooling mode at least 25 minutes. If conditions
are favorable, check system charge by subcooling method. If any
adjustment is necessary, adjust charge slowly and allow system to
operate for 25 minutes to stabilize before declaring a properly
charged system.
If the indoor temperature is below 70°F (21.11°C), or the outdoor
temperature is not in the favorable range, adjust charge for line set
length above or below 15ft (4.57 m) and indoor fan coil /furnace
coil per Table 1 and 2. Charge level should then be appropriate for
the system to achieve rated capacity. The charge level should then
be checked at another time when the both indoor and outdoor
temperatures are in a more favorable range.
NOTE: If the line length is beyond 80ft (24.38 m) or greater than
20ft (6.10 m) vertical separation see Long line guideline for special
charging requirement.
A14573
Fig. 9 – Adjusting Charge Using Service Valve Subcool
Fig. 10 – Service Valve Subcool Target Value
A14575
A14574
9
Table 1—Required Charge Adjustment for Indoor Coil Model -- HP
Outdoor Model Size
Furnace or Fan Coil Model Number
/
---
13
24B
25
36
37
48
60
CNPV*18**
---
/
/
/
/
/
/
CAP**18**
---
/
/
/
/
/
/
CNP**24
---
/
/
/
/
/
/
CNPV*19**
---
/
/
/
/
/
/
CAP**24
---
/
/
/
/
/
/
CSPH*24
---
/
/
/
/
/
/
CSPH*30**
/
/
/
/
/
/
/
F(E,V)4(A,B,C)NF002
+0.19
---
---
---
---
/
/
CAP**30
/
---
/
/
/
/
/
CNP**30
/
---
/
/
/
/
/
CNP**36
/
---
---
---
---
/
/
F(E,V)4(A,B,C)N(B,F)003
/
---
---
---
---
/
/
CAP**36
/
---
---
---
---
/
/
CNP**42
/
+.50
---
---
+.75
/
/
CAP**42
/
+.50
---
---
+.75
/
/
CSPH*36
/
/
---
---
+.75
/
/
CSPH*42**
/
/
+.75
+.75
+.75
/
/
CNP**31**
/
/
+.75
+.75
+.75
/
/
CNP**48
/
/
+.75
+.75
+.75
---
/
CSPH*48**
/
/
+.75
+.75
+1.00
---
/
CNP**37
/
/
/
/
/
/
/
CNP**43
/
/
/
/
/
/
/
CAP**48
/
/
/
+.75
+1.00
---
/
CNP**60
/
/
/
/
+1.00
---
-----
CSPH*60
/
/
/
/
+1.00
---
F(E,V)4(A,B,C)N(B,F)005
/
/
+.75
+.75
+1.00
---
/
F(E,V)4(A,B,C)NB006
/
/
/
/
+1.00
+2.2
+1.00
CAP**60
/
/
/
/
/
+2.2
+1.00
/
/
/
/
/
/
/
CNP**61
= Comb. not allowed
= No charge adjust for ID
Table 2—Required Charge Adjustment for Indoor Coil Model -- AC
Furnace or Fan Coil Model Number
Outdoor Model Size
36
37
13
24B
25
48
49
60
CNPV*18**
---
/
/
/
/
/
/
/
CAP**18**
---
/
/
/
/
/
/
/
CNP**24
---
---
---
/
/
/
/
/
CNPV*19**
---
/
/
/
/
/
/
/
CAP**24
---
---
---
/
/
/
/
/
CSPH*24
---
---
---
/
/
/
/
/
CSPH*30**
/
---
---
/
/
/
/
/
F(E,V)4(A,B,C)NF002
+0.19
---
---
---
/
/
/
/
CAP**30
/
---
---
/
/
/
/
/
CNP**30
/
---
---
/
/
/
/
/
CNP**36
/
---
---
---
---
/
/
/
F(E,V)4(A,B,C)N(B,F)003
/
---
---
---
---
/
/
/
CAP**36
/
---
+.50
---
---
/
/
/
CNP**42
/
+.50
+.50
---
+.75
/
/
/
CAP**42
/
+.50
+.50
---
+.75
/
/
/
CSPH*36
/
+.50
+.50
---
+.75
/
/
/
CSPH*42**
/
+.50
+.50
+.75
+.75
/
/
/
CNP**31**
/
+.50
+1.25
+.75
+.75
/
/
/
CNP**48
/
+.50
+1.25
+.75
+.75
---
---
/
CSPH*48**
/
+.625
+1.25
+.75
+1.00
---
---
/
CNP**37
/
+.625
+1.25
+.75
+1.00
---
---
/
CNP**43
/
+.625
+1.25
+.75
+1.00
---
---
/
CAP**48
/
/
/
+.75
+1.00
---
---
/
CNP**60
/
/
/
/
+1.00
---
+0.125
-----
CSPH*60
/
/
/
/
+1.00
---
+0.125
F(E,V)4(A,B,C)N(B,F)005
/
+.625
+1.25
+.75
+1.00
---
+0.125
/
F(E,V)4(A,B,C)NB006
/
/
/
+.75
+1.00
+1.5
+.625
+1.00
CAP**60
/
/
/
/
/
+1.5
+.625
+1.00
/
/
/
/
/
+1.5
+.625
+1.00
CNP**61
/ = Comb. not allowed
--- = No charge adjust for ID
10
Fig. 12 – Charging in Cooling Mode 288BNV013
Fig. 16 – Charging in Cooling Mode 288BNV037
Fig. 13 – Charging in Cooling Mode 288BNV024
Fig. 17 – Charging in Cooling Mode 288BNV048
Fig. 14 – Charging in Cooling Mode 288BNV025
Fig. 18 – Charging in Cooling Mode 288BNV060
Fig. 15 – Charging in Cooling Mode 288BNV036
11
Fig. 19 – Charging in Cooling Mode 189BNV013
Fig. 23 – Charging in Cooling Mode 189BNV037
Fig. 20 – Charging in Cooling Mode 189BNV024B
Fig. 24 – Charging in Cooling Mode 189BNV048
Fig. 21 – Charging in Cooling Mode 189BNV025
Fig. 25 – Charging in Cooling Mode 189BNV049
Fig. 22 – Charging in Cooling Mode 189BNV036
Fig. 26 – Charging in Cooling Mode 189BNV060
12
Heating Check Chart Procedure (See Fig.27 - 33)
(Communicating / Non-- communicating Systems)
In heating mode, the required charging method is by weigh--in. On
new installations or complete recharge, refer to the unit 0 and
indoor fan coil / furnace coil per Table 1 for additional charge
needed. Refrigerant charge adjustment amount for adding or
removing 0.6 oz/ft (17.74 g/m) of 3/8 liquid line above or below
15ft (4.57 m) respectively.
Use the Defrost CHECKOUT mode to remove ice or frost from
coil, if present, prior to checking the heating pressures.
To use the Heating Check Chart, the user interface (UI) must be in
Refrigerant Charging mode selected from the Installation and
Service screen. The Charging Mode Selection screen will show
selections for Weigh--In Charge Method or Heating Check Charge
Method. Select Heating Check Charge Method. The Heating
Check Charge method will only be displayed if the conditions are
right for checking the charge in heating mode. When Heating
Check Charge Method is selected, the system will operate by
running in stage 5 with appropriate outdoor fan speed and indoor
airflow. Upon completion of a countdown period for system
stabilization, check refrigerant pressures for the appropriate
ambient temperatures shown in Fig. 27 through 33 based the OD
unit size.
To use the Heating Check Chart in non--communicating systems,
operate system at Y1+Y2–high stage. These charts indicate
whether a correct relationship exists between system operating
pressure and air temperature entering indoor and outdoor units. If
pressure and temperature do not match on chart, system refrigerant
charge may not be correct. DO NOT USE CHART TO ADJUST
REFRIGERANT CHARGE.
NOTE: High pressure is at vapor service valve. Add 12 psig if
high pressure is taken from liquid service valve.
NOTE: When charging is necessary during heating season, charge
must be weighed in accordance with unit rating plate, ±0.6 oz./ft
(±17.74 g/m). of 3/8--in. liquid--line above or below 15 ft (4.57
m), respectively.
Fig. 29 – Heating Pressure Check Chart 288BNV025
Fig. 30 – Heating Pressure Check Chart 288BNV036
Fig. 31 – Heating Pressure Check Chart 288BNV037
Fig. 27 – Heating Pressure Check Chart 288BNV013
Fig. 32 – Heating Pressure Check Chart 288BNV048
Fig. 28 – Heating Pressure Check Chart 288BNV024
Fig. 33 – Heating Pressure Check Chart 288BNV060
13
TROUBLESHOOTING
Table 3—Factory Supplied Model Plug Information
Service Tool
Fig. 34 – Service Tool Connection
A150062
When working on the outdoor unit of a split system, the technician
would usually need to repeatedly walk between the indoor wall
control and the unit outside. To save time, the communicating
controls offer a service tool feature.
By wiring the service tool into the AOC board and powering it
with an external adapter, the technician can have a wall control
capable of running the system right at the outdoor unit.
To use a service tool, connect the A and B communication bus
wires from this second communicating control to the terminals
marked A and B on the terminal strip located in the bottom left
corner of the AOC board (see Fig. 34). But instead of connecting
the wires on the service tool to the terminals marked C and D,
connect the C and D wires from the service tool to the 24V and C
on ST1 as shown in Fig. 34.
When the service tool is connected and powered up, the
communicating controls inside the home will ”go to sleep” and let
the service tool take control of the system. In this manner, the
service technician can run the diagnostic checkouts right at the
outdoor unit using the service tool.
After the checkouts are completed and it is no longer necessary to
use the service tool, remove it from the communicating controls
and the indoor communicating controls will regain control in about
two minutes.
Systems Communication Failure
If communication is lost with the User Interface (UI), the Green
LED will be off. Check the wiring to the User Interface and the
indoor and outdoor units and power.
Model Plug
Each control board contains a model plug. The correct model plug
must be installed for the system to operate properly (see Table 3).
The model plug is used to identify the type and size of unit to the
control.
On new units, the model and serial numbers are inputted into the
AOC board’s memory at the factory. If a model plug is lost or
missing at initial installation, the unit will operate according to the
information input at the factory and the appropriate error code will
flash temporarily. An RCD replacement AOC board contains no
model and serial information. If the factory control board fails, the
model plug must be transferred from the original board to the
replacement board for the unit to operate.
When installing heat pump with older fan coils, a model plug
change may be required.
NOTE: The model plug takes priority over factory model
information input at the factory. If the model plug is removed after
initial power up, the unit will operate according to the last valid
model plug installed, and flash the appropriate fault code
temporarily.
288BNV
MODEL PLUG
NUMBER
Pins 1--- 4
Pins 2--- 3
13
24B
25
36
37
48
60
HK70EZ029
HK70EZ009
HK70EZ001
HK70EZ002
HK70EZ026
HK70EZ003
HK70EZ004
11K
5.1K
5.1K
5.1K
11K
5.1K
5.1K
220K
91K
11K
18K
120K
24K
33K
189BNV
MODEL PLUG
NUMBER
Pins 1--- 4
Pins 2--- 3
13
24B
25
36
37
48
49
60
HK70EZ028
HK70EZ010
HK70EZ011
HK70EZ012
HK70EZ025
HK70EZ013
HK70EZ027
HK70EZ014
11K
5.1K
5.1K
5.1K
11K
5.1K
11K
5.1K
180K
120K
150K
180K
91K
220K
150K
270K
Status Codes
!
ATTENTION
Unit may occasionally become unresponsive due to certain
combinations of previous fault codes. There may not be
anything wrong with the unit or components. The unit may
require a high voltage power cycling for at least 2 minutes or
longer to clear the condition. If the condition persists, conduct
further troubleshooting per Service Manual.
Table 6 shows the status codes flashed by the amber status light.
Most system problems can be diagnosed by reading the status code
as flashed by the amber status light on the control board.
The codes are flashed by a series of short and long flashes of the
status light. The short flashes indicate the first digit in the status
code, followed by long flashes indicating the second digit of the
error code.
The short flash is 0.25 seconds ON and the long flash is 1.0 second
ON. Time between flashes is 0.25 seconds. Time between short
flash and first long flash is 1.0 second. Time between code
repeating is 2.5 seconds with LED OFF.
Codes are easily read from user interface (UI)
EXAMPLE:
3 short flashes followed by 2 long flashes indicates a 32 code.
Table 6 shows this to be low pressure switch open.
Status Code Recall Mode
Active status codes are stored in memory even when power is
absent. The most recent flashing status code (highest priority
active) can be recalled from memory via Status Code Recall Mode
and displayed using the amber LED. The Status Code Recall
Mode is accessed by shorting (use a clip wire) the “force defrost”
connector (labeled J2 on the board) and then power ON the unit.
Please make sure the unit is turned OFF before shorting the pins.
Status Code Recall Mode will continue as long as the “force
defrost” terminals remain shorted. The unit will not attempt to heat
or cool while the terminals remain shorted. Once the status code is
read, power--down the unit and remove the short.
Utility Interface With Evolution Connex Control
The utility curtailment relay should be wired between the two
UTIL connections on the control board for this Evolution
Communicating System (see Fig. 35). This input allows a power
utility device to interrupt compressor operation during peak load
periods. When the utility sends a signal to shut the system down,
the User Interface status screen will display, ”Curtailment Yes”.
See UI installation instructions for setup details.
14
Utility Relay
A13414
Fig. 35 – Variable Speed Control Board with optional Utility Relay
Variable Speed Compressor Winding Resistance
Table 4—Variable Speed Compressor Resistance
(winding resistance at 70_F 20_F)
This compressor operates with 3--phase variable frequency PWM
variable voltage. For troubleshooting certain fault codes related to
compressor resistances, follow these steps:
1. Disconnect compressor power leads from the inverter MOC
terminals, U (YEL), V (RED), and W (BLK).
2. Measure the resistance between YEL to RED, YEL to BLK,
and RED to BLK and compare to Table 4 values. Each
resistance set should be equal.
3. Measure the resistance to ground for each lead.
4. If the resistances check out, reconnect power leads to
appropriate terminal.
5. If the resistances appear to be abnormal, it will be necessary
to measure the resistance at the compressor fusite terminals.
6. During the removal of the compressor fusite cap, do not remove the RTV sealant. Remove the harness plug, measure
the resistances, and compare to Table 4.
7. Special care will need to be taken with the replacement of
the compressor fusite cap. Make sure the two holes in the
compressor fusite terminal box are still full of RTV sealant
before the cap is reinstalled. The factory RTV can be reused
as long as none of it has been removed during the cap
removal.
8. Reinstall compressor sound blanket making sure discharge
thermistor and compressor power harness are routed as they
were from the factory
MODEL 288BNV / 189BNV (OHMs)
WINDING
Between
terminals
Between
terminal &
ground
13, 24B
25
36
37, 48
49, 60
1.13
.59
.59
.37
.24
>1 mega
!
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
and/or improper operation.
Do not use Meggar for measuring the winding resistance.
!
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
and/or improper operation.
To maintain water integrity of the compressor fusite terminal
box, the two holes in outer ring need to be full of RTV sealant.
15
Fan Motor
Low Pressure Protection
If verification of proper operation is required for the fan motor
used in this unit, follow these steps:
1. Disconnect fan motor connector from control board.
2. Measure resistance between any 2 of the 3 leads present.
3. Compare measurement to values below
The outdoor unit is equipped with low pressure transducer. If the
control senses a low pressure per the table below, it will respond as
follows:
Fan Motor Resistance
Unit Size
Resistance (Ohms)
13, 24B
21.2
25, 36, 37, 48, 49 (AC), 60
11.1
Cooling
Low
Pressure
3 minute
operation
Cool
mode
resume
operation
begins
Low
Pressure
(No Operation)
Heating Low
Pressure
5 minute
operation
Heat
mode
resume
operation
begins
<= 33
> 43
<= 15
<= 33
> 35
1. Display the appropriate error code on the status LED (see
Table 6).
2. If a demand persists after the 6--minute delay and the
pressure has reached the operation level, then resume
operation. Reset the 6 minute timer, clear the displayed
error code and communicate cleared error to the User
Interface. Status LED reverts to operation code display.
3. If a demand persists after the 6--minute delay but the
pressure has not recovered, turn off the ODF. If the pressure
recovers any time after the 6 minute delay, then resume
operation. Reset the 6 minute timer, clear the displayed
error code and communicate cleared error to the User
Interface. Status LED reverts to operation code display.
4. If a pressure drops below the NO--operation level three (3)
consecutive times, then lock out operation for 4 hours and
flash the appropriate error code and communicate lockout
status to the User Interface. The trip counter will reset to
zero if 15 minutes of successful operation occurs before the
3rd trip is recorded. Record the low pressure lockout in the
historical data.
5. In the event of a low pressure trip or low pressure lockout,
check the refrigerant charge and indoor airflow (cooling)
and outdoor fan operation and outdoor coil in heating.
Brown-- Out Protection
If the line voltage is less than 187V for at least 4 seconds, the
Compressor and OD fan goes to 0 rpm. Compressor and fan
operation are not allowed until voltage is a minimum of 190V. The
control will flash the appropriate fault code (see Table 6).
230V Line (Power Disconnect) Detection
The control board senses the presence of absence of 230V through
inverter feedback. Voltage should present at all times when system
is in service regardless if system is running or standby. If there is
no 230V at the inverter when the indoor unit is powered with a
cooling or heating demand, the appropriate fault code is displayed
on UI (communicating only – see Fig. 39). If system is configured
with conventional heat pump thermostat (non--communicating), no
fault code will be displayed on AOC board, nor will any status
LEDs be lit. Use multimeter to check for the presence of 230V in
this situation.
High Pressure Switch Protection
Suction Pressure Transducer (SPT)
If the accuracy of the transducer is questioned, the technician can
check it while it is attached to the AOC board. Connect a gage
manifold to the suction valve gage port fitting.
At the AOC board, with the wire harness receptacle exposing a
portion of the three pins on the AOC board, a DC voltmeter can
read the DC voltage between ground and supply (input) terminal.
Ensure that the input voltage is 5 VDC. Next, read the DC voltage
across the ground and output terminal. Record the output voltage.
The suction pressure that the pressure transducer is reading can be
calculated by taking the output voltage and subtracting 0.5 from it
then taking that difference and multiplying it by 50. Pressure
(psig) = 50.0 x (DCV out -- 0.5). For example, if the measured
voltage is 3.0 VDC: 50 X (3.0 -- 0.5) -- 50 X 2.5 = 125 psig. See
Fig. 36.
6
5
4
Output Voltage (V)
The outdoor unit is equipped with a high pressure switch. If the
control senses the opening of a high pressure switch (open 600+/--5
psig, close 470+/--10 psig @77_F), it will respond as follows:
1. Display the appropriate fault code (see Table. 6).
2. After a 6 minute delay, if there is a call for cooling or heating and HPS is reset, the PEV opens for 150 seconds to
equalize system pressures. The compressor and fan will then
ramp to the next lower stage of operation until demand is
satisfied. The staging down and resetting to the highest
stage will end after 2 hours of accumulated operation without further HPS trips.
3. A system malfunction will occur after repeated HPS faults
and the stages have reached the lowest level. This could
take five consecutive HPS trips if the first occurred in stage
5 demand or 1 HPS trip if in stage 1 demand.
4. In the event of a high--pressure switch trip or high--pressure
lockout, check the refrigerant charge, outdoor fan operation,
and outdoor coil (in cooling) for airflow restrictions, or indoor airflow in heating.
3
2
1
0
0
25
50
75
100
125
150
175
200
225
Pressure - Sealed Gauge (psi)
Fig. 36 – Suction Pressure Transducer (SPT)
Output Funtion Graph
16
A12035
Temperature Thermistors
Thermistor Sensor Comparison
Thermistors are electronic devices which sense temperature. As the
temperature increases, the resistance decreases.
10Kohm
thermistors are used to sense outdoor air temperature (OAT), coil
temperature (OCT) and the suction line temperature (OST) located
between the reversing valve and the accumulator. A 50Kohm
thermistor is used to sense discharge temperature (ODT).
Refer to Table 5 and Fig. 37 and 38 for resistance values versus
temperature.
The control continuously monitors and compares the outdoor air
temperature sensor and outdoor coil temperature sensor to ensure
proper operating conditions. The comparison is:
S In cooling if the outdoor air sensor indicates  10_F ( 5.6_C)
warmer than the coil sensor (or) the outdoor air sensor indicates
 25_F ( 15_C) cooler than the coil sensor, the sensors are out
of range.
S In heating if the outdoor air sensor indicates  35_F ( 19.4_C)
warmer than the coil sensor (or) the outdoor air sensor indicates
 10_F ( 5.6_C) cooler than the coil sensor, the sensors are out
of range.
If the sensors are out of range, the control will flash the appropriate
fault code as shown in Table 6.
Table 5—10K/50Kohm Resistance Values vs Temperature
10Kohm
_C (_F)
TEMPERATURE
25.0 (77.0)
0.0 (32.0)
-28.0 (-18.4)
50Kohm
125.0 (257.0)
75.0 (167.0)
25.0 (77.0)
RESISTANCE (ohms)
10.0 + / --- 2.3%
32.6 + / --- 3.2%
85.5 + / --- 3.4%
Failed Thermistor Default Operation
1.7 + / --- 1.6%
7.40 + / --- 2.0%
50.0 + / --- 2.3%
THERMISTOR CURVE
90
RESISTANCE (KOHMS)
80
70
60
50
40
30
20
10
0
0
20
40
60
80
TEMPERATURE (DEG. F)
100
120
A91431
Fig. 37 – 10K Thermistor Resistance Versus Temperature
RESISTANCE (KOHMS)
50K THERMISTOR
450
400
350
300
250
200
150
100
50
0
0
20
40
60
80
100
Factory defaults have been provided in the event of failure of
outdoor air thermistor (OAT) and/or outdoor coil thermistor
(OCT).
If the OAT sensor should fail, defrost will be initiated based on coil
temperature and time.
If the OCT sensor should fail, defrost will occur at each time
interval during heating operation, but will terminate after 2
minutes.
If there is a thermistor out--of--range error, defrost will occur at
each time interval during heating operation, but will terminate after
2 minutes.
Count the number of short and long flashes to determine the
appropriate flash code. Fig. 39 and Table 6 gives possible causes
and actions related to each error.
Maximum Power Mode -- Inverter Over Temperature
The outdoor unit is equipped with inverter temperature sensing. If
the inverter senses a temperature above the high threshold limit it
will respond as follows:
1. Display the local fault code only on the AOC Status LED.
2. The system will continue to run but attempt to mitigate by
speed reduction.
3. When the system demand is satisfied, the unit will shut
down.
4. If the fault is still active on the AOC Status LED, the ODF
will continue to run at 500 RPM until the inverter
temperature falls below the threshold.
5. The compressor will not restart if the fault is still active.
120
TEMPERATURE (°°F)
A14022
Fig. 38 – 50K Thermistor Resistance Versus Temperature
If the outdoor air or coil thermistor should fail, the control will
flash the appropriate fault code (see Table 6).
IMPORTANT: The outdoor air thermistor, coil thermistor and
suction thermistor should be factory mounted in the final locations.
Check to ensure thermistors are mounted properly (See Fig. 2,
3, 4, 5 and 6).
17
Fig. 39 – Fault Code Label
18
Table 6—Fault Code Actions
Flash Code
Type
Amber LED Description
Reset
Time
Mode
Possible Causes
ON, no flash
Standby
1, pause
Variable Capacity
Normal Operation
for communicating
system
1 (2 sec ON),
longer pause
(1 second
OFF)
Variable Capacity (Range
Cutback)
Speed Limiting for
communicating systems
1, pause
2 ---stage ”Low” Capacity
Low capacity for
non ---communicating
2, pause
2 ---stage ”High” Capacity
High capacity for
non ---communicating
4, pause
2 ---stage ”Reduced” Capacity
Speed Limiting for
non ---communicating systems
25
System
Malfunction
INVALID MODEL PLUG/INVERTER SIZE
NA
Both
Actions
Missing model plug
Install the correct model plug
Wrong Model Plug
Installed
Verify correct model plug installed
Damaged Model
Plug
Check model plug for corrosion or breakage; replace if necessary. Check Model
Plug resistance per the wiring diagram
Model Plug not fully
engaged on board
Align per the silkscreen layout
Incorrect Model Plug
with Inverter Size
Replace plug or inverter with correct size
(If model plug is for 2 Ton but Inverter is 3
Ton, fault code 25 will be shown)
Damaged AOC control
Replace AOC control
31
Fault
HIGH PRESSURE SWITCH
OPEN
(Stage down for each occurrence, elevates to fault
code 84 when it occurs
while running on the lowest
stage. Reduced capacity is
cleared when system has
been continuously running
at any stage for 2 hours
with reduced capacity.)
32
Local
LOW PRESSURE TRIP
(Elevates to fault code 83
after 3 occurrences)
6 Minutes
Both
Refer to fault code 83
Local
LOST INVERTER COMMUNICATIONS
(Occurs aftr 2 minutes of no
communications between
AOC and MOC)
(Elevates to fault code 48
after 3 consecutive failures
within 20 minute or 20 minutes continuous loss of
connection)
NA
Both
Refer to fault code 48
33
46
48
49
Local
System
Malfunction
Local
BROWNOUT EVENT
LOST INVERTER COMMUNICATIONS
(Elevated from fault code
33 after 3 occurrences)
COMPRESSOR OVER
CURRENT FAULT
(Elevates to fault code 95
after 5 occurrences)
6 Minutes
(then reduced
stage operation)
Both
Refer to fault code 84
6 Minutes
NA
6 Minutes
Both
Both
Both
19
Low line voltages
Check for line voltage approximately
greater than180V. If voltage less than 180V
and if persistent contact power provider
Bad connection on
L1 and L2
Check for connection on line and load
side to verify connection is good.
Inverter not reading
proper voltage
Verify no action issue from the above list
then replace inverter.
Loose or disconnected harness (Hardness between AOC
(PL20) and MOC)
Verify good harness connection
Radio or Electrical
noise
System will try to self ---mitigate with repeated start attempts
Possible damage to
inverter
change out the Inverter drive
Refer to fault code 95
Flash Code
53
54
55
Type
Fault
Fault
Fault
Amber LED Description
OUTDOOR AIR TEMP SENSOR FAULT
SUCTION TEMP SENSOR
FAULT
COIL TEMP SENSOR
FAULT
Reset
Time
NA
NA
NA
Mode
Both
Both
Both
Possible Causes
Actions
Sensor Harness not
connected to AOC
control
Ensure plug is connected to AOC control
Broken or loose harness wire
Check harness for continuity; see resistance chart to check resistance at given
temperature
Broken or Damaged
Sensor
Check harness for continuity; see resistance chart to check resistance at given
temperature
Hardware damage to
AOC control
Replace AOC control
Sensor Harness not
connected to AOC
control
Ensure plug is connected to AOC control
Broken or loose harness wire
Check harness for continuity; see resistance chart to check resistance at given
temperature
Suction Thermistor
not properly attached or in wrong
location
Ensure Sensor is properly attached to the
accumulator entry ---tube
Broken or Damaged
Sensor
Check harness for continuity; see resistance chart to check resistance at given
temperature
Hardware damage to
AOC control
Replace AOC control
Sensor Harness not
connected to AOC
control
Ensure plug is connected to AOC control
Broken or loose harness wire
Check harness for continuity; see resistance chart to check resistance at given
temperature
Coil Thermistor not
properly attached or
in wrong location
Ensure Sensor is properly clipped to the
distributor entry ---tube
Broken or Damaged
Sensor
Check harness for continuity; see resistance chart to check resistance at given
temperature
Hardware damage to
AOC control
Replace AOC control
Check fuse on AOC control
Cool
Heating when cooling is demanded
Check wiring between AOC and reversing
valve
troubleshoot reversing valve
Inspect outdoor coil for obstructions
56
Event
OAT ---OCT THERMISTOR
OUT OF RANGE
NA
Both
57
Fault
SUCTION PRESSURE
SENSOR FAULT
NA
Both
20
Coil Thermistor not
properly attached or
in wrong location
Ensure Sensor is properly clipped to the
distributor entry ---tube
Outdoor Ambient
Temperature sensor
improperly installed
(sensor body may
be in contact with
sheet metal)
Properly install OAT sensor
Sensor Harness not
connected to AOC
control
Ensure plug is connected to AOC control
Broken or loose harness wire
Check harness
Electrical short destroyed Transducer
electronics
Compare transducer reading to gauge
reading at service valve (see transducer
measurement chart); Check system for
electrical shorts and correct; replace transducer
Heat damage during
brazing
Compare transducer reading to gauge
reading at service valve (see transducer
measurement chart); replace transducer
Flash Code
59
61
Type
Amber LED Description
Reset
Time
Mode
Local
DISCHARGE TEMP OUT
OF RANGE EVENT
(Stage down for each occurrence, elevates to fault
code 74 after 5 occurrence.
Reduced capacity is
cleared if demand cycle is
satisfied without ODT
reaching limit, or system
has been continuously running at any stage for 2
hours with reduced capacity)
15 Minutes
Both
Local
FAN INVERTER FAULT
(elevates to fault code 76
after 5 occurrences)
Local
FAN INVERTER CURRENT
FAULT
(elevates to fault code 86
after 5 occurrences)
6 Minutes
Both
Possible Causes
Actions
Refer to fault code 74
Fan motor failed to
start
Troubleshoot outdoor fan motor & blade
and make sure they are working
Fan motor rotor misalignment
System will attempt to run again
Refer to fault code 76
63
65
66
67
68
Local
Event
Event
Event
DC VOLTS LOW --- SPEED
LIMITING
OUTDOOR FAN DROPPED
OUT
STATOR HEATER FAULT
10 MIN STAGE 2 WARMUP
DELAY
6 Minutes
NA
6 Minutes
6 Minutes
10 Minutes
Both
Both
Both
Both
Both
Cool
69
System
Malfunction
INVERTER/COMPRESSOR
INTERNAL FAULT (Elevates
to this fault code after 5 hidden occurrences of itself)
Heat
15 Minutes
Both
71
72
Event
Local
COMPRESSOR DROPPED
OUT
SUCTION OVER TEMPERATURE EVENT
(elevates to fault code 82
after 3 occurrences)
6 Minutes
15 Minutes
Both
Both
21
Refer to fault code 86
Caused by other
fault code shut down
System will attempt to run again
Low supply line voltage (< 197 VAC)
Check supply voltage to ODU; if low contact utility provider
Loose wire in control
box area
Loose wire: check for loose wire in ODU
Inverter internal
damage
Replace Inverter
MOC is reporting
that fan motor isn’t
running
Troubleshoot fan motor and make sure it
is working
3T Inverter enters
test mode
Replace inverter with latest software
There is a demand
for stator heat but
MOC doesn’t detect
it
Check compressor winding resistance or
miswire of compressor leads at terminals
U,V,W
Damaged inverter
generating other inoperable fault codes
such as 88, 95
Replace Inverter
High voltage power
cycle
No action
Overcharged System
Check system subcooling to determine
charge status, if high remove charge using
Charging Mode (follow proper charging
procedures)
Overcharged System
Check charge in heating mode per heating
check charge chart. If pressures do not
match then pull out charge, weigh in using
heating charge method
Phase imbalance/
compressor or inverter miswire
Check compressor winding resistance or
miswire of compressor leads at terminals
U,V,W
Flooded start
Troubleshoot EXV & TXV
Inverter damage
Replace inverter
Compressor damage
Replace compressor
MOC is reporting
that compressor isn’t
running
Refer to TIC 2015 ---0017 for more details
3T Inverter enters
test mode
Replace inverter with latest software
Refer to fault code 82
Flash Code
74
Type
System
Malfunction
Amber LED Description
DISCHARGE TEMP OUT
OF RANGE LOCKOUT
(Elevated from fault code
59 after 5 occurrences)
Reset
Time
Mode
Possible Causes
Actions
Cool
High Load conditions
Over charge: Check system charge
Heat
Low Charge or Loss
of Charge at low ambient heating conditions
Check charge in heating mode per heating
check charge chart. If pressures do not
match then pull out charge, weigh in using
heating charge method
Heat
Expansion Device
Restriction
Heating: Trouble shoot EXV (coil, harnesses); Trouble shoot the TXV
Power Cycle system, is EXV moving on
power up (audible)
Sensor Harness not
connected to AOC
control
Ensure plug is connected to AOC control
Broken or loose harness wire
Check harness for continuity; see resistance chart to check resistance at given
temperature
Broken or Damaged
Sensor
Check harness for continuity; see resistance chart to check resistance at given
temperature
Indoor Unit Airflow
too low or off
Troubleshoot indoor fan motor and make
sure it is working
Outdoor Unit Airflow
too low or off
Troubleshoot outdoor fan motor and make
sure it is working
Reversing Valve Bypass or Reversing
Valve not energized
Reversing Valve stuck halfway
Ensure AOC fuse is good
24 VDC in cooling mode
Check harness and connectors
Both
Hardware damage to
AOC control
Replace AOC control
Both
Nuisance fault during non ---operational
mode
Refer to TIC 2015 ---0017 for more details
Heat
Indoor Airflow too
low or off
Check indoor airflow
Outdoor Airflow too
low or off
Check ODU coil for clogging (ice or debris) and clean if necessary; Troubleshoot
ODU fan motor and make sure it is working
Blocked Inverter
Heat Exchanger
(fins)
Check Inverter fins for debris and clean if
necessary
Application violates
guideline
Consult Application Guideline for compliance
Fan blade bent/out
of balance
Check outdoor fan blade
Check for ice build up
Fan blade restricted
Check outdoor fan blade clearance
Check for ice build up
Fan motor wiring
Check outdoor fan motor connectors and
harness
Fan motor
Replace outdoor fan motor
2 Hours
Both
75
76
Local
System
Malfunction
MAXIMUM POWER MODE
--- TEMP (Temporary RPM
reduction or stage lowering
will result)
FAN INVERTER LOCKOUT
(Elevated from fault code
61 after 5 occurrences)
NA
Both
2 Hours
Both
Cool
Heat
77
Local
MAXIMUM POWER MODE
--- COMP CURRENT
(Temporary RPM reduction
or stage lowering will result)
NA
Both
22
Inverter damage
Replace inverter
Overcharged System
Check system subcooling to determine
charge status, if high remove charge using
Charging Mode (follow proper charging
procedures)
Overcharged System
Check charge in heating mode per heating
check charge chart. If pressures do not
match then pull out charge, weigh in using
heating charge method
Compressor is operating outside the allowed operational
envelope
Inverter will reduce speed to a lower stage
Incorrect refrigerant
charge
Check refrigerant amount
Outdoor Airflow too
low or off
Check ODU coil for clogging (ice or debris) and clean if necessary; Troubleshoot
ODU fan motor and make sure it is working
Incoming power supply voltage
Check voltage versus unit rating plate for
allowable range
Loose or incorrect
wire connections
Check incoming power leads and leads to
the compressor plug
Flash Code
Type
Amber LED Description
Reset
Time
Mode
Possible Causes
Actions
79
Local
COMPRESSOR/INVERTER
FAULT
(Elevates to fault code 88
after 5 occurrences)
6 Minutes
Both
Compressor fails to
start
System will try to self ---mitigate with repeated start attempts
82
83
System
Malfunction
System
Malfunction
SUCTION OVER TEMP
LOCKOUT
(Elevated from fault code
72 after 3 occurrences)
LOW PRESSURE LOCKOUT FOR 4 HOURS
(Elevated from fault code
32 after 3 occurrences)
Refer to fault code 88
Cool
Undercharged System
Check system subcooling to determine
charge status, if low add charge using
Charging Mode (follow proper charging
procedures)
Cool
Uninsulated vapor
line
Insulate the vapor line
Cool
Indoor TXV operation
Troubleshoot TXV
Heat
Undercharged System
Check charge in heating mode per heating
check charge chart. If pressures do not
match then pull out charge, weigh in using
heating charge method
Heat
Outdoor EXV operation
Troubleshoot EXV
Both
Reversing valve bypass
Troubleshoot reversing valve
Cool
Service Valve left
closed (Liquid or Vapor)
Ensure Service Valves are open
Cool
Undercharged System
Check system subcooling to determine
charge status, if low add charge using
Charging Mode (follow proper charging
procedures)
Cool
Indoor Airflow too
low or off
Check Indoor for clogging (ice or debris)
and clean or de ---ice if necessary; Troubleshoot Indoor fan motor and make sure
it is working; follow Indoor Airflow troubleshooting instruction
Cool
Restriction in Circuits
or Tubing
Repair restriction
Heat
EXV Malfunction
Troubleshoot EXV (see guide below)
Heat
Service Valve left
closed (Liquid Service Valve)
Ensure Liquid Service Valve is open
Heat
Outdoor Airflow too
low or off
Check Outdoor for clogging (ice or debris)
and clean or de ---ice if necessary; Troubleshoot Outdoor fan motor and make
sure it is working; follow Outdoor Airflow
troubleshooting instruction
Heat
Undercharged System
Check charge in heating mode per heating
check charge chart. If pressures do not
match then pull out charge, weigh in using
heating charge method
Both
Restriction in Filter
Drier
Check for temperature drop across filter
drier and replace if necessary
Both
Expansion Device
Restriction
If short lineset (less than 15 ft.) Troubleshoot TXV (see guide below); replace if
necessary
4 Hours
4 Hours
23
Flash Code
84
86
Type
System
Malfunction
System
Malfunction
Amber LED Description
HIGH PRESSURE LOCKOUT FOR 4 HOURS
(Elevated from fault code
31 when the stage (speed)
can no longer be lowered)
FAN INVERTER CURRENT
LOCKOUT
(Elevated from fault code
63 after 5 occurrences)
Reset
Time
Mode
Possible Causes
Actions
Cool
Outdoor Airflow too
low or off
Check Outdoor Coil for clogging (ice or
debris) and clean or de ---ice if necessary;
Troubleshoot Outdoor fan motor and
make sure it is working; follow Outdoor
Airflow troubleshooting instruction
Cool
Overcharged System
Cool
TXV malfunction (Indoor) causing an
overcharged condition
Cool
Restriction in EXV
assembly plus Long
Line Application
leading to Overcharge when charging in Cooling mode
Troubleshoot EXV
Cool
Restriction in Circuits
or Tubing
Repair restriction
Heat
Indoor Airflow too
low or off
Troubleshoot indoor fan motor and make
sure it is operating; follow indoor airflow
troubleshooting instruction. Check Indoor
coil or filter for restriction (debris) and
clean if necessary;
Heat
Furnace plus Heat
pump application:
Furnace stuck on
If not in Defrost and Furnace is running
same time as heat pump, troubleshoot
Furnace
Heat
Overcharged System
Remove refrigerant, evacuate and
recharge system using weigh in method.
Return to check charge to subcooling
when conditions are favorable in cooling
mode
Heat
Reversing Valve
Stuck in Cooling
troubleshoot reversing valve
Both
Service Valve left
closed (Liquid or Vapor)
Ensure Service Valves are open
Both
Loose High Pressure
Switch harness
leads
Check HPS harness, pins and connectors
Both
Pressure Switch disconnected from the
inverter
Check HPS connection to the inverter
Both
Restriction of filter
drier
Check for temperature drop across filter
drier and replace if necessary
Both
Non ---condensable
leading to high pressure situation
Remove refrigerant, replace filter drier,
evacuate and recharge system
Both
Faulty Pressure
Switch
Check Discharge pressure with gauge, if
less than 600 +/ --- 20 psig and switch is
open (measure resistance) then replace
pressure switch
Both
Expansion Device
Restriction
4 Hours
5 minutes
Both
24
Check system charge using Cooling
Charging Mode (follow proper charging
procedures)
Troubleshoot TXV
Troubleshoot EXV
Sudden supply voltage change
Investigate incoming voltage
Restriction on fan rotation / motor
Troubleshoot outdoor fan motor & blade
and make sure they are working.
Intermitent harness
plug connection
Check harness and connectors. Make
sure there is a positive lock between the
harness and the board
Fan blade bent/out
of balance
Replace fan blade
Inverter damage
Replace inverter
Flash Code
88
91
92
Type
System
Malfunction
Amber LED Description
COMPRESSOR / INVERTER LOCKOUT
(Elevated from fault code
79 after 5 occurrences)
Reset
Time
2 Hours
Local
INVERTER VDC ---OUT
OVER VOLTAGE EVENT
(Elevates to fault code 97
after 5 occurrences)
5 Minutes
Local
INVERTER VDC ---OUT UNDER VOLTAGE EVENT (Elevates to fault code 96 after
5 occurrences)
5 Minutes
Mode
Both
Both
Possible Causes
Actions
Blocked Inverter
Heat Exchanger
(fins)
Check Inverter fins for debris and clean if
necessary
Condenser Airflow
too low or off
Check Condenser (IDU in heating, ODU in
cooling) for clogging (ice or debris) and
clean if necessary; Troubleshoot fan motor
and make sure it is working
Evaporator Airflow
too low or off
Check Evaporator (IDU in cooling, ODU in
heating) for clogging (ice or debris) and
clean if necessary; Troubleshoot fan motor
and make sure it is working
High Load conditions at cold ambient
heating or high ambient cooling
Over charge: Check system charge
Inverter damage
Replace inverter
Compressor is suddenly unloaded
Check that the service valves are fully
open
Refer to fault code 97
Both
Cool
Refer to fault code 96
Outdoor Airflow too
low or off
Check ODU coil for clogging (ice or debris) and clean if necessary; Troubleshoot
ODU fan motor and make sure it is working
Troubleshoot TXV
95
System
Malfunction
COMPRESSOR OVER
CURRENT LOCKOUT
(Elevated from fault code
49 after 5 occurrences)
Both
High superheat
Both
Compressor is operating outside the allowed operational
envelope
Inverter will reduce speed to a lower stage
Incoming power supply voltage
Check voltage versus unit rating plate for
allowable range
Loose or incorrect
wire connections
Check incoming power leads and leads to
the compressor plug
Phase imbalance
Check compressor winding resistance or
miswire of compressor leads at terminals
U,V,W
Refrigerant overcharge
Check refrigerant amount
2 Hours
Both
Both
96
97
98
System
Malfunction
VDC UNDER VOLTAGE
LOCKOUT
(Elevated from fault code
92 after 5 occurrences)
System
Malfunction
VDC OVER VOLTAGE
LOCKOUT
(Elevated from fault code
91 after 5 occurrences)
Event
HIGH TORQUE EVENT
(Event will cause stage
down and when stage is at
lowest level, will elevate to
fault code 99)
2 Hours
2 Hours
NA
Troubleshoot EXV
Both
Both
Both
Both
25
Check suction pressure transducer and
suction temperature sensor
Inverter damage
Replace inverter
Compressor internal
damage
Replace compressor
Low supply line voltage (< 197 VAC)
Check supply voltage to ODU; if low contact utility provider
Inverter internal
damage
Replace Inverter
High supply line voltage (> 253 VAC)
Check supply voltage to ODU; if high contact utility provider
Inverter internal
damage
Replace Inverter
Compressor is operating outside the allowed operational
envelope
Inverter will reduce speed to a lower stage
Refer to fault code 99
Flash Code
99
Type
System
Malfunction
Amber LED Description
HIGH TORQUE LOCKOUT
(Elevated from fault code
98 when 98 occurs at lowest stage)
Reset
Time
Mode
Possible Causes
Actions
Cool
Overcharged System
Check system subcooling to determine
charge status, if high remove charge using
Charging Mode (follow proper charging
procedures)
Heat
Overcharged System
Check charge in heating mode per heating
check charge chart. If pressures do not
match then pull out charge, weigh in using
heating charge method
Both
Miswire
Check miswire of compressor leads at terminals U,V,W
Both
Outdoor Airflow too
low or off
Check ODU coil for clogging (ice or debris) and clean if necessary; Troubleshoot
ODU fan motor and make sure it is working
Both
Expansion Device
Restriction
Heat
Overcharged System
2 hours
26
Troubleshoot TXV
Troubleshoot EXV
Check charge in heating mode per heating
check charge chart. If pressures do not
match then pull out charge, weigh in using
heating charge method
Variable Speed Drive LED Location and Description (Sizes 13 and 24B)
LED 200
LED 207
STATUS
COMM
MOC LED Description (Sizes 13 and 24B)
Reference
LED200
Color
Status
Steady
On
Off
Steady
On
Red
LED207
Amber
Condition
Description
Normal
Indicates MOC powered where DC bus at 40volts or higher
Abnormal
No power, capacitor voltage drained
Normal
Blinking
Abnormal
Off
Normal
Compressor is running
If compressor stops, it indicates some fault happening;
If compressor is running, it indicates speed is limited or reduced.
Compressor stops and no fault
AOC LED Descriptions (Sizes 13 and 24B)
Reference
Color
STATUS
Amber
COMM
Green
Status
Steady
On
Blinking
Steady
On
Condition
Description
Normal
AOC status---standby mode
Abnormal
AOC function/fault status
Normal
Communication from AOC to indoor wall control
LED Not Functioning Properly --- Requires AOC or Inverter Replacement
Reference
Color
STATUS
Amber
COMM
Green
Suspect AOC board
If Amber STATUS light is not on (neither steady nor blinking), with power to outdoor unit
In Communicating mode, if Green COMM LED is not on
when AB indoor wires are connected to AOC AB connector
and indoor has communications
Failure Description
AOC STATUS is not functioning properly and AOC board
should be replaced.
AOC is not capable of communicating with indoor; AOC
board should be replaced.
UI Fault Codes requiring AOC or Inverter Replacement
Fault Code Description
Fault Code
Communications Loss
179
Failure Description
Loss of communication with outdoor unit AOC board;
AOC or Inverter may need to be replaced
NOTE: If any of the AOC control board header pins are damaged or are not making good contact, AOC board should be replaced.
27
Variable Speed Drive LED Location and Description (Sizes 25, 36, 37, 48, 49 and 60)
MOC LED Description (Sizes 25, 36, 37, 48, 49 AND 60)
Reference
Color
LD1
Red
LED1
Red
LED3
Amber
LD5
Green
Reference
Color
STATUS
Amber
COMM
Green
Reference
Color
STATUS
Amber
COMM
Green
Status
Steady On
Off
Steady On
Off
Steady On
Off
Blinking
Steady On
Off
Description
MOC powered where DC bus is 40volts or greater
No power, capacitor voltage drained
DCF and board DC high voltage and discharge circuit powered on
No power
MOC board switching power supply to power AOC board on
No Power
Indicates communication from MOC to AOC
Indicates 5 volt connection status OK between AOC and MOC
No Power
AOC LED Descriptions (Sizes 25, 36, 37, 48, 49 AND 60)
Status
Steady On
Blinking
Steady On
Description
AOC status --- standby mode
AOC function/fault status
Communication from AOC to indoor wall control
LED Not Functioning Properly --- Requires AOC or Inverter Replacement
Suspect AOC board
If Amber STATUS light is not on (neither steady nor blinking), with power to outdoor unit
In Communicating mode, if Green COMM LED is not on
when AB indoor wires are connected to AOC AB connector
and indoor has communications
Failure Description
AOC STATUS is not functioning properly and AOC board
should be replaced.
AOC is not capable of communicating with indoor; AOC
board should be replaced.
UI Fault Codes requiring AOC or Inverter Replacement
Fault Code Description
Fault Code
Communications Loss
179
Failure Description
Loss of communication with outdoor unit AOC board;
AOC or Inverter may need to be replaced
NOTE: If any of the AOC control board header pins are damaged or are not making good contact, AOC board should be replaced.
28
COMPRESSOR POWER HARNESS ASSEMBLY REPLACEMENT
(Reference RCD Instruction # 99TA516170)
The following is a recommended procedure for compressor power
harness replacement. Always refer to the unit product installation,
start--up & service instructions for detailed procedures.
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Turn off and lock out all power to unit before proceeding.
Discharge all capacitors before proceeding
All wiring and electrical connections shall comply with all
local and national electrical codes.
!
WARNING
7. Remove top two screws holding control box and remove
compressor harness (highlighted in yellow below).
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
failure to follow this warning could result in personal injury.
Do not operate compressor or provide any electrical power to
the compressor unless the terminal box cover is in place and
secured.
Measurements of amps and volts during running conditions
must be taken at other points in the power supply.
Do not provide any power to the compressor unless suction
and discharge service valves are open.
Replacement Procedure
1. Follow all safety warnings and notices.
2. Precautions must be taken when servicing components
within the control box of this unit. The technician
performing the service must determine that it is safe to work
on or near the inverter. The electrical disconnect that
provides power to the unit must be turned off, locked and
tagged out. This will insure that no damage will occur to the
inverter, controls or other equipment and will prevent injury
if contact is made with the electrical equipment. Wait a
minimum of two minutes before servicing the unit to allow
inverter capacitors to discharge. Follow safety instructions
located on unit control box cover.
3. Remove the control box cover.
4. Disconnect compressor power harness from inverter.
5. Remove service panel to gain access to unit wiring and
compressor compartment.
6. Cut the wire tires securing the compressor power harness to
the control box. Remove compressor power harness (from
control box). Replace wire tie with supplied wire tie; do not
fasten at this time. The second wire tie for the choke on the
compressor is supplied with new harness on the replacement
compressor (highlighted with the yellow circles below).
8. Cut double loop wire tie on suction tube holding
compressor harness, replace with new one provided; do not
fasten at this time. Note how the compressor harness is
routed to suction tube. (Highlighted in yellow below)
29
9. With using a slot screwdriver, lift up the on the side tab to
pry the cover off from the RTV. Be sure not to break the tab.
12. Remove cover, unplug old harness, plug in new harness,
verify bushing is reinstalled and plug leads leave the
terminal box through the bushing; reinstall cover pushing
one side down then the other.
NOTE: DO NOT SCRAP SEALANT
10. It may be necessary to leverage the screwdriver against
cover next to tab so as not to break the tab while loosening.
13. Reinstall compressor sound blanket making sure discharge
thermistor and compressor power harness are routed as they
were from the factory.
14. Route compressor power harness to new double loop wire
tie and then to the wire retainers in tube sheet (route as they
were originally to make sure they will not contact fan blade)
and then route into control box and reinstall two control
box screws. (See image below)
11. Once Cover is loosened on one side, use screwdriver along
freed edge to remove.
15. Reinstall service panel.
16. Route compressor harness choke to left hand side of the top
of control box and push in wire tie. Pull wires tight as they
enter control box and tighten second wire tie.
17. Reconnect compressor power harness to the inverter.
NOTE: Reference enclosed wiring diagrams and unit
wiring diagrams in Owner’s Manual to aid in reattaching
electrical connections.
18. Reinstall control box cover.
30
INVERTER ASSEMBLY w SHIELD GASKET REMOVAL AND INSTALLATION
(Reference RCD Instruction # 99TA512018) Also see figures 41 through 42
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Turn off the electrical supplies to the unit before performing
any maintenance or service. Follow the operating instructions
on the label attached to the unit
!
CAUTION
ELECTRICAL OPERATION HAZARD
Failure to follow this caution may result in unit damage or
improper operation.
Label all wires prior to disconnection when servicing controls.
Wiring errors can cause improper and dangerous operation.
IMPORTANT: DO NOT USE POWER TOOLS TO
TIGHTEN THE INVERTER INPUT SCREW TERMINALS
Removing Inverter:
1. Remove power to the unit. Wait a minimum of two minutes
before servicing the unit to allow inverter capacitors to
discharge. Follow safety instructions located on unit control
box cover.
2. Precautions must be taken when servicing components
within the control box of this unit. The technician
performing the service must determine that it is safe to work
on or near the inverter. The electrical disconnect that
provides power to the unit must be turned off, locked and
tagged out. This will insure that no damage will occur to the
inverter, controls or other equipment and will prevent injury
if contact is made with the electrical equipment.
3. Remove the control box cover.
4. The inverter capacitors are covered with a protective shield.
The shield should not be removed from the inverter.
5. Before servicing the inverter, verify the inverter voltage is
zero. Measure the DC voltage at the DC + VOLTAGE and
DC -- VOLTAGE terminals on the inverter adjacent to the
capacitors to ensure that they have totally discharged.
The voltage at these terminals must be 0 (zero) before
servicing (see following figures).
6. After verifying the voltage has dissipated to zero,
disconnect wiring from the inverter.
7. Disconnect three compressor power wires. Note wire color
order – Yellow, Red, and Black.
8. Disconnect fan motor power harness plug.
9. Disconnect reversing valve / PEV plug. (See Figure Below)
10. Disconnect high pressure switch plug.
11. Disconnect EXV plug.
12. Disconnect suction pressure transducer plug.
13. Disconnect suction thermistor plug.
14. Disconnect discharge thermistor plug.
15. Disconnect OAT/OCT plug.
16. Disconnect control wiring (ABCD or thermostat
connections)
17. Disconnect two input power wires. Note wire color order –
Black and Yellow.
18. Disconnect inverter ground lead. Note wire color – Green
w/ Yellow Stripe.
19. Remove 12 mounting screws and pull out inverter with
cover intact.
Installing New Inverter:
1. Install inverter into control box. Attach (12) mounting
screws.
2. Re--connect inverter ground lead. Note wire color – Green
w/ Yellow Stripe.
3. Re--connect two input power wires. Note wire color order-Black and Yellow.
4. Re--connect control wiring (ABCD or thermostat
connections)
5. Re--connect OAT/OCT plug.
6. Re--connect discharge thermistor plug.
7. Re--connect suction thermistor plug.
8. Re--connect suction pressure transducer plug.
9. Re--connect EXV plug.
10. Re--connect high pressure switch plug.
11. Re--connect reversing valve / PEV plug.
12. Re--connect fan motor power harness plug.
13. Re--connect three compressor power wires. Note wire color
order-- Yellow, Red and Black.
14. Replace the control box cover.
15. Apply power to the unit.
31
Fan Motor
Harness Plug
Compressor
Power Harness
Wires Yel, Red,
Blk
Fig. 40 – Compressor and Fan Harness
(Unit sizes 13 and 24B)
Fig. 41 – Compressor and Fan Harness
(Unit sizes 25, 36, 37, 48, 49 and 60)
32
Reversing
Valve PLUG
EXV PLUG
Discharge
Thermistor
PLUG
Inverter Ground
Wire, GRN / YEL
Stripes
Inverter Input
Power Wires BLK
and YEL
High
Pressure
Switch PLUG
OAT/OCT PLUG
Suction
Thermistor
Thermis
PLUG
ABCD PLUG
Fig. 42 – Wire Harness Connections
(Unit sizes 13 and 24B)
Fig. 43 – Wire Harness Connections
(Unit sizes 25, 36, 37, 48, 49 and 60)
33
Suction
Pressure
Transducer
PLUG
COMPRESSOR REPLACEMENT
(Reference RCD Instruction # 99TA516169)
The following is a recommended procedure for compressor
replacement. Always refer to the unit product installation, start--up
& service instructions for detailed procedures.
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Turn off and lock out all power to unit before proceeding.
Discharge all capacitors before proceeding
All wiring and electrical connections shall comply with all
local and national electrical codes.
!
WARNING
PERSONAL INJURY HAZARD
failure to follow this warning could result in personal injury.
Follow recognized safety practices and wear safety glasses,
protective clothing, and gloves. Acids formed as a result of
motor burnout can cause burns.
!
WARNING
PERSONAL INJURY HAZARD
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
Do not leave system open to atmosphere. compressor oil is
highly susceptible to moisture absorption.
At the time of compressor change out and at regular preventative
maintenance intervals the acid/moisture content of the system
should be checked using an acid/moisture test kit. This can
determine, in a few minutes, whether acid and moisture are present
in the system. No oil sample is required. Contact your local
distributor to purchase this device.
Before Changing the Compressor
Check compressor and associated controls to be sure compressor
replacement is necessary.
Failure Classification
The replacement procedure is dependent on the type of failure.
The following describes the classification process:
MECHANICAL FAILURES
1. No damage to windings
as indicated by electrical check
1.
Windings of compressor
open or grounded
2.
3.
2.
3.
Oil dark with burn odor
Symptoms Blows fuses or
circuit breaker Draws abnormal amount of current
failure to follow this warning could result in personal injury.
do not disassemble bolts, plugs, fittings, etc. until all pressure
has been relieved from compressor.
!
WARNING
PERSONAL INJURY HAZARD
failure to follow this warning could result in personal injury.
Do not operate compressor or provide any electrical power to
the compressor unless the terminal box cover is in place and
secured. Measurements of amps and volts during running
conditions must be taken at other points in the power supply.
Do not provide any power to the compressor unless suction
and discharge service valves are open.
!
CAUTION
UNIT DAMAGE HAZARD
failure to follow this caution may result in equipment damage
or improper operation.
Only suction line filter driers should be used for refrigerant
and oil clean up.
CAUTION
Oil clean and odor free
Symptoms:Excessive
Noise Won’t Pump
Excessively Hot
ELECTRICAL BURNOUT
Replacement Procedure for Mechanical Failure
1. Follow all safety warnings and notices.
2. Precautions must be taken when servicing components
within the control box of this unit. The technician
performing the service must determine that it is safe to work
on or near the inverter. The electrical disconnect that
provides power to the unit must be turned off, locked and
tagged out. This will insure that no damage will occur to the
inverter, controls or other equipment and will prevent injury
if contact is made with the electrical equipment. Wait a
minimum of two minutes before servicing the unit to allow
inverter capacitors to discharge. Follow safety instructions
located on unit control box cover.
3. Remove and recover all refrigerant from system until
pressure gauges read 0 psi. Use all service ports. Never open
a system under a vacuum to atmosphere. Break vacuum
with dry nitrogen holding charge first. Do not exceed 5
psig.
4. Remove the control box cover.
5. Disconnect compressor power harness from inverter.
6. Remove service panel to gain access to unit wiring and
compressor compartment.
Use of non--approved products could limit system life and
void unit warranty.
34
10. Remove compressor mounting hardware.
11. Cut both suction and discharge lines with tubing cutter. Do
not use brazing torch for compressor removal as oil vapor
may ignite when compressor is disconnected.
12. Using caution and the appropriate lifting devices, remove
compressor from the unit.
13. Scratch matching marks on stubs in old compressor. Make
corresponding marks on replacement compressor.
14. Use torch to remove stubs from old compressor and install
them in replacement compressor.
NOTE: Use appropriate protection to avoid damage to
compressor terminal cover and/or terminal box sealant with
torch flame. It is intended that terminal cover remain
installed during compressor installation.
15. Using caution and the appropriate lifting device, place
replacement compressor in unit and secure with appropriate
mounting hardware.
NOTE: Use of existing or new OEM mounting hardware is
recommended.
NOTE: Compressor grommet and sleeve supplied with the
compressor should be evaluated versus OEM hardware
before assembling in unit.
16. Use copper couplings to tie compressor back into system.
NOTE: Use appropriate protection to avoid damage to
compressor terminal cover and/or terminal box sealant with
torch flame. It is intended that terminal cover remain
installed during compressor installation.
17. Remove and discard liquid line strainer and filter drier.
Replace with filter drier one size larger in capacity than the
unit being worked on (use bi--flow) type on heat pump. See
Recommended Filter/Drier Sizes table below for appropriate
size.
18. Reinstall compressor sound blanket making sure discharge
thermistor and compressor power harness are routed as they
were from the factory.
19. Route compressor power harness to new double loop wire
tie and then to the wire retainers in tube sheet (route as they
were originally to make sure they will not contact fan blade)
and then route into control box and reinstall two control
box screws. (See image below)
7. Cut the wire tires securing the compressor power harness to
the control box. Remove compressor power harness (from
control box). Replace wire tie with one supplied; do not
fasten at this time. The second wire tie for the choke on the
compressor is supplied with new harness on the replacement
compressor (highlighted with the yellow circles below).
8. Remove top two screws holding control box and remove
compressor harness (highlighted in yellow below).
9. Cut double loop wire tie on suction tube holding
compressor harness, replace with new one provided; do not
fasten at this time. Note how the compressor harness is
routed to suction tube (highlighted in yellow below).
35
20. Reinstall service panel.
21. Route compressor harness choke to left hand side of the top
of control box and push in wire tie. Pull wires tight as they
enter control box and tighten second wire tie.
22. Reconnect compressor power harness to the inverter.
NOTE: Reference enclosed wiring diagrams and unit
wiring diagrams in Owner’s Manual to aid in reattaching
electrical connections.
23. Triple evacuate the system below 1,000 microns.
24. Recharge unit, compensating for larger liquid line filter.
Charge compensation for oversize filter drier is listed in the
Recommended Filter/Drier Sizes table below.
25. Check system for normal operation. If unit is a heat pump,
switch from heating to cooling a few times to verify
component operation.
Replacement Procedure for Electrical Burnout
(System Clean--up)
Mild Burnout
Perform steps 1 – 25 as specified in the Replacement Procedure for
Mechanical Failure and then perform steps as follows:
26. Run unit a minimum of 2 hours and replace liquid line filter
drier.
27. Use a test kit to determine whether acceptable acid and
moisture levels have been attained. If system is still
contaminated, repeat step 17. Continue this process until the
test kit indicates “clean” system.
28. Check system for normal operation. If unit is a heat pump,
switch from heating to cooling a few times to verify
component operation.
Severe Burnout
Perform steps 1 – 22 as specified in the Replacement Procedure for
Mechanical Failure and then perform steps as follows:
23. Clean or replace TXV.
24. Drain any trapped oil from the accumulator if used.
25. Add suction line filter drier for appropriate unit size as
indicated in Recommended Filter/Drier Sizes table below.
Mount vertical with pressure taps on both inlet and outlet.
NOTE: On heat pumps, install suction line drier between
compressor and accumulator.
26. Triple evacuate the system below 1,000 microns.
27. Recharge unit, compensating for larger liquid line filter.
Charge compensation for oversize filter drier is listed in
Recommended Filter/Drier Sizes table below.
28. Run 1 hour minimum and change liquid line drier and
suction filter.
29. Run a minimum of 2 or more hours and change liquid filter
drier again. Remove suction line filter from system (do not
replace suction line filter).
30. Use a test kit to determine whether acceptable acid and
moisture levels have been attained. If system is still
contaminated, repeat Step 22. Continue this process until
the test kit indicates “clean” system.
31. Check system for normal operation. If unit is a heat pump,
switch from heating to cooling a few times to verify
component operation.
Recommended Filter/Drier Sizes
36
Unit
Capacity
Quantity
1, 2, 3, 4,
and 5
1
Minimum Required
Effective Desiccant Volume
Liquid CU. IN.
Suction CU.
IN.
6.5
15
WIRING DIAGRAMS -- 189BNV
Fig. 44 – 189BNV WIRING DIAGRAM -- Sizes 13 and 24B
CONNECTION DIAGRAM
OFM
V
W
UNIT OPERATION
This control board contains a 3.5 minute short cycle protector. A 3.5 minute delay will occur between
Compressor off/on cycles. To bypass delay, short forced defrost pins for 1 second then release.
However, there is an additional 2.5 minutes delay upon expiration of the 3.5 minute short cycle delay to
ensure the high and low side pressures are equalized. This is important for long term rotary compressor
reliability. It is a delay that cannot and must not be bypassed. The internal crankcase heater is energized
during off cycle as needed.
COMP
(R) U
(C) W
BLK
U
YEL
RED
(S) V
YEL
RED
BLK
CHOKE
CHOKE
DC+ LD1
RED
YEL
4
1 2
DC FAN
U
BLK
DC-
W
V
MOTOR & COMPRESSOR
CONTROL SECTION
NOTES:
BLU
BLU
F L1 L2
1. To Be Wired In Accordance With National Electric Code (N.E.C.) And Local Codes.
2. Use Copper Conductors Only. Use Conductors Suitable For At Least 75ºC (167ºF).
3. Two Wire A and B Required For Communication. If Outdoor Unit Improperly
Grounded, Connect Indoor Ground To “C” Terminal.
4. If Any Of The Original Wire, As Supplied, Must Be Replaced, Use The Same Or
Equivalent Wire.
5. Check All Electrical Connections Inside Control Box For Tightness.
6. Do Not Attempt To Operate Unit Until Service Valves Have Been Opened.
7. If Communicating, Must Use With Infinity or Evolution User Interface Listed In
Pre-sale Literature Only.
8. For Non-Communicating Thermostats, 24VAC To Be Provided To R Connection.
9. N.E.C. class 2, 24 V circuit, min. 40 VA required, 60 VA on units installed with LLS.
HPS
HPS
BLU/PNK
BLU/PNK
MOTOR CONTROL COMM HEADER
HP CONTROL COMM HEADER
PEV
RVS
FUSE 3 AMP
PL10
120
30
60
1
SW2
60
30
90
BLU BLU
12
PL19
J2
FORCED
DEFROST
STATUS COMM
PEV
PL17
AIR CONDITIONER
CONTROL SECTION
YEL
SPT
1
OST
-LEGENDBLK
+
WHT
RED
BLK
OST
PL16
MODEL
YEL
OCT
GRN
LVCH
L2
OAT
SYSTEM COMMUNICATION
COMPRESSOR
HIGH VOLTAGE INDICATOR LED
HIGH PRESSURE SWITCH
LOW VOLTAGE CHOKE HARNESS
MODEL PLUG
OUTDOOR AIR THERMISTOR
OUTDOOR COIL THERMISTOR
OUTDOOR DISCHARGE THERMISTOR
OUTDOOR FAN MOTOR
OUTDOOR SUCTION THERMISTOR
PRESSURE EQUALIZER VALVE
SUCTION PRESSURE
TRANSDUCER
STATUS SYSTEM FUNCTION LIGHT
DEFROST TIME SELECT
SW2
TERMINAL BLOCK
TB
UTILITY CURTAILMENT
UTIL
24 VOLTS DC
24V
MODEL
OAT
OCT
ODT
OFM
OST
PEV
SPT
* MAY BE FACTORY OR FIELD INSTALLED
BRN
L1
COMM
COMP
LD1
HPS
LVCH
ODT
1
UTILITY INTERFACE
CHOKE
TB
23
BLK
1
PL15
24V UTIL C R Y1 Y2 W O
21
BLK
ODT
PL18
GRN
FACTORY POWER WIRING
FIELD POWER WIRING
FACTORY CONTROL WIRING
FIELD CONTROL WIRING
COMPONENT CONNECTION
JUNCTION
FIELD SPLICE
PLUG CONNECTION
BLK
1
BLK
SPT
BLK
BRN
OCT
BLK
MODEL PLUG CHART
MODEL MODEL PIN RESISTANCE (K )
PLUG
SIZE
HK70EZ 1 - 4 (R1) 2 - 3 (R2)
OAT
25
36
37
48
49
60
EQUIP GND
208/230 1Ø POWER SUPPLY
011
012
025
013
027
014
5.1K
5.1K
11K
5.1K
11K
5.1K
150K
180K
091K
220K
150K
270K
Fig. 45 – 189BNV WIRING DIAGRAM -- Sizes 25, 36, 37, 48, 49, 60
37
340613-101 REV. C
WIRING DIAGRAMS -- 288BNV
Fig. 46 – 288BNV WIRING DIAGRAM -- Sizes 13 and 24B
Fig. 47 – 288BNV WIRING DIAGRAM -- Sizes 25, 36, 37, 48, and 60
38
REFRIGERATION SYSTEM
Refrigerant
!
WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could result in personal injury
or equipment damage.
Puronr refrigerant which has higher pressures than R--22 and
other refrigerants. No other refrigerant may be used in this
system. Gauge set, hoses, and recovery system must be
designed to handle Puronr. If you are unsure consult the
equipment manufacturer.
In an air conditioning and heat pump system, refrigerant transfers
heat from one replace to another. The condenser is the outdoor coil
in the cooling mode and the evaporator is the indoor coil.
In a heat pump, the condenser is the indoor coil in the heating
mode and the evaporator is the outdoor coil.
In the typical air conditioning mode, compressed hot gas leaves the
compressor and enters the condensing coil. As gas passes through
the condenser coil, it rejects heat and condenses into liquid. The
liquid leaves condensing unit through liquid line and enters
metering device at evaporator coil. As it passes through metering
device, it becomes a gas--liquid mixture. As it passes through
indoor coil, it absorbs heat and the refrigerant moves to the
compressor and is again compressed to hot gas, and cycle repeats.
4. Perform required service.
5. Remove and dispose of any oil contaminated material per
local codes.
Brazing
This section on brazing is not intended to teach a technician how to
braze. There are books and classes which teach and refine brazing
techniques. The basic points below are listed only as a reminder.
Definition: The joining and sealing of metals using a nonferrous
metal having a melting point over 800_F/426.6_C.
Flux: A cleaning solution applied to tubing or wire before it is
brazed. Flux improves the strength of the brazed connection.
When brazing is required in the refrigeration system, certain basics
should be remembered. The following are a few of the basic rules.
1. Clean joints make the best joints. To clean:
 Remove all oxidation from surfaces to a shiny
finish before brazing.
 Remove all flux residue with brush and water while
material is still hot.
2. Silver brazing alloy is used on copper--to--brass,
copper--to--steel, or copper--to--copper. Flux is required
when using silver brazing alloy. Do not use low temperature
solder.
3. Fluxes should be used carefully. Avoid excessive
application and do not allow fluxes to enter into the system.
4. Brazing temperature of copper is proper when it is heated to
a minimum temperature of 800_F and it is a dull red color
in appearance.
Compressor Oil
!
CAUTION
Service Valves and Pumpdown
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
PERSONAL INJURY AND UNIT DAMAGE HAZARD
Failure to follow this warning could result in personal injury
or equipment damage.
The compressor in a Puronr system uses a Polyol Ester
(POE) oil. This oil is extremely hygroscopic, meaning it
absorbs water readily. POE oils can absorb 15 times as much
water as other oils designed for HCFC and CFC refrigerants.
Take all necessary precautions to avoid exposure of the oil to
the atmosphere.
Servicing Systems on Roofs With Synthetic
Materials
POE (Polyol Ester) compressor lubricants are known to cause long
term damage to some synthetic roofing materials. Exposure, even if
immediately cleaned up, may cause embrittlement (leading to
cracking) to occur in one year or more. When performing any
service which may risk exposure of compressor oil to the roof, take
appropriate precautions to protect roofing. Procedures which risk
oil leakage include but are not limited to compressor replacement,
repairing refrigerants leaks, replacing refrigerant components such
as filter drier, pressure switch, metering device, coil, accumulator,
or reversing valve.
Synthetic Roof Precautionary Procedure
1. Cover extended roof working area with an impermeable
polyethylene (plastic) drop cloth or tarp. Cover an
approximate 10 x 10 ft area.
2. Cover area in front of the unit service panel with a terry
cloth shop towel to absorb lubricant spills and prevent
run--offs, and protect drop cloth from tears caused by tools
or components.
3. Place terry cloth shop towel inside unit immediately under
component(s) to be serviced and prevent lubricant run--offs
through the louvered openings in the base pan.
WARNING
Never attempt to make repairs to existing service valves. Unit
operates under high pressure. Damaged seats and o--rings
should not be replaced. Replacement of entire service valve is
required. Service valve must be replaced by properly trained
service technician.
Service valves provide a means for holding original factory charge
in outdoor unit prior to hookup to indoor coil. They also contain
gauge ports for measuring system pressures and provide shutoff
convenience for certain types of repairs.
The service valve is a front--seating valve, which has a service port
that contains a Schrader fitting. The service port is always
pressurized after the valve is moved off the front--seat position.
The service valves in the outdoor unit come from the factory
front--seated. This means that the refrigerant charge is isolated from
the line--set connection ports. The interconnecting tubing (line set)
can be brazed to the service valves using industry accepted
methods and materials. Consult local codes.
Before brazing the line set to the valve, the belled ends of the sweat
connections on the service valves must be cleaned so that no brass
plating remains on either the inside or outside of the bell joint. To
prevent damage to the valve and/or cap “O” ring, use a wet cloth
or other acceptable heat--sinking material on the valve before
brazing. To prevent damage to the unit, use a metal barrier between
brazing area and unit.
After the brazing operation and the refrigerant tubing and
evaporator coil have been evacuated, the valve stem can be turned
counterclockwise until back--seats, which releases refrigerant into
tubing and evaporator coil. The system can now be operated.
39
The service valve--stem cap is tightened to 20  2 ft/lb torque and
the service--port caps to 9  2 ft/lb torque. The seating surface of
the valve stem has a knife--set edge against which the caps are
tightened to attain a metal--to--metal seal.
The service valve cannot be field repaired; therefore, only a
complete valve or valve stem and service--port caps are available
for replacement.
If the service valve is to be replaced, a metal barrier must be
inserted between the valve and the unit to prevent damaging the
unit exterior from the heat of the brazing operations.
!
CAUTION
PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal injury.
Wear safety glasses, protective clothing, and gloves when
handling refrigerant.
Pumpdown & Evacuation
!
CAUTION
ENVIRONMENTAL HAZARD
Failure to follow this caution may result in environmental
damage.
Federal regulations require that you do not vent refrigerant to
the atmosphere. Recover during system repair or final unit
disposal.
If this system requires either a Pump Down or Evacuation for any
reason, the procedures below must be followed:
Pump Down - Evolution Communicating - 288BNV
Because this system is inverter controlled, compressor, suction
pressure transducer and EXV, conventional procedure cannot be
used to “pump down” and isolate the refrigerant into the outdoor
unit. The UI (User Interface) has provisions to assist in performing
this function.
1. Connect gauges to 288BNV liquid and vapor service valve
ports to monitor operating pressures during and at completion of the procedure.
2. In the advanced menu of the UI, go to Checkout > Heat
Pump> Pumpdown
3. Select mode to pump down in (COOL or HEAT), COOL
mode allows refrigerant to be isolated in outdoor unit.
HEAT mode allows the refrigerant to be isolated in indoor
coil and lineset. Set desired time period. Default time period for the procedure is 120 minutes.
4. Select Start on UI to begin the pump--down process. Unit
will begin running in selected mode after a brief delay.
5. Close the liquid service valve.
6. The unit will run in selected mode with the low pressure
protection set to indicate pump--down is complete when the
suction pressure drops below 10 psig. Compressor protections are still active to prevent damage to the compressor or
inverter (high pressure, high current, high torque, etc.) .
7. Once system indicates pump--down complete or failure to
complete shutdown, close vapor service valve.
8. A small quantity of charge will remain in isolated section of
system dependent on ambient temperature and overall system charge. This charge must be manually recovered. A
recovery system will be required to remove final quantity of
refrigerant from indoor coil and line set.
9. Remove power from indoor and heat pump unit prior to servicing unit.
Pump Down - Evolution Communicating - 189BNV
Because this system is inverter controlled, compressor, suction
pressure transducer, conventional procedure cannot be used to
“pump down” and isolate the refrigerant into the outdoor unit. The
UI (User Interface) has provisions to assist in performing this
function.
1. Connect gauges to 189BNV liquid and vapor service valve
ports to monitor operating pressures during and at completion of the procedure.
2. In the advanced menu of the UI, go to Checkout > Pumpdown
3. Select mode to pump down in (COOL). Set desired time
period. Default time period for the procedure is 120 minutes.
4. Select Start on UI to begin the pump--down process. Unit
will begin running in selected mode after a brief delay.
5. Close the liquid service valve.
6. The unit will run in selected mode with the low pressure
protection set to indicate pump--down is complete when the
suction pressure drops below 10 psig. Compressor protections are still active to prevent damage to the compressor or
inverter (high pressure, high current, high torque, etc.) .
7. Once system indicates pump--down complete or failure to
complete shutdown, close vapor service valve.
8. A small quantity of charge will remain in isolated section of
system dependent on ambient temperature and overall system charge. This charge must be manually recovered. A
recovery system will be required to remove final quantity of
refrigerant from indoor coil and line set.
9. Remove power from indoor and outdoor unit prior to servicing unit.
Pump Down – Using 2-- stg HP Tstat - 288BNV
(Non-- Communicating)
Because this system has an inverter controlled compressor, suction
pressure transducer and EXV, conventional procedure cannot be
used to “pump down” and isolate the refrigerant into the outdoor
unit.
1. Connect gauges to 288BNV liquid and vapor service valve
ports to monitor operating pressures during and at
completion of the procedure.
2. Force system to operate in high stage by creating a large
differential between room temperature and set point on
thermostat. Use multi--meter to verify that 24 VAC is
present between C and Y1 and Y2 terminals at outdoor unit.
3. Close the liquid service valve.
4. The unit will continue to run until high or low pressure
switches open. Close vapor service valve once compressor
shuts down.
5. Remove power from indoor and heat pump unit prior to
servicing unit.
6. A quantity of charge will remain in isolated section of
system dependent on ambient temperature and overall
system charge. This charge must be manually recovered. A
recovery system will be required to remove final quantity of
refrigerant from indoor coil and line set.
Pump Down – Using 2-- stg Tstat - 189BNV
(Non-- Communicating)
Because this system has an inverter controlled compressor, suction
pressure transducer, conventional procedure cannot be used to
“pump down” and isolate the refrigerant into the outdoor unit.
1. Connect gauges to 189BNV liquid and vapor service valve
ports to monitor operating pressures during and at
completion of the procedure.
2. Force system to operate in high stage by creating a large
differential between room temperature and set point on
thermostat. Use multi--meter to verify that 24 VAC is
present between C and Y1 and Y2 terminals at outdoor unit.
40
3. Close the liquid service valve.
4. The unit will continue to run until high or low pressure
switches open. Close vapor service valve once compressor
shuts down.
5. Remove power from indoor and outdoor unit prior to
servicing unit.
6. A quantity of charge will remain in isolated section of
system dependent on ambient temperature and overall
system charge. This charge must be manually recovered. A
recovery system will be required to remove final quantity of
refrigerant from indoor coil and line set.
Evacuation and recovery of refrigerant from 288BNV
Because this system has an EXV for the heating expansion device,
additional steps may be taken to open the EXV for fastest
refrigerant recovery and evacuation. If the EXV is not open when
pulling a vacuum or recovering refrigerant from the heat pump
unit, extended evacuation time may be required and/or inadequate
vacuum obtained. The UI (User Interface) has provisions to open
the EXV for refrigerant recovery and/or evacuation.
1. Connect gauges to 288BNV liquid and vapor service valve
ports to monitor operating pressures during and at completion of the procedure. Attach recovery system or vacuum
pump to gauge set as needed for the service procedure. The
service valves must be open to evacuate the unit through the
line set service ports. The suction capillary service port is a
direct connection to the suction port of the compressor and
may also be used.
2. In the advanced menu of the UI, go to Checkout > Heat
Pump > Evacuation.
3. Set desired time period. Default time period for the procedure is 120 minutes.
4. Select START on UI to open the valve.
5. Begin evacuation or refrigerant recovery as required for the
procedure after UI indicates the EXV is open. Power may
be removed from heat pump after the UI indicates “READY
TO EVACUATE.”
6. Remove power from indoor and heat pump unit prior to servicing unit. The EXV will retain the open position.
NOTE: See service training materials for troubleshooting the EXV
using EXV CHECK mode.
Evacuation and recovery of refrigerant from 288BNV
when using non-- communicating thermostat
Refrigerant recovery and evacuation can be performed without a
UI (User Interface) but will take more time. If EXV is not forced
open the recovery and evacuation must rely on check valve as a
bypass.
1. Connect gauges to 288BNV liquid and vapor service valve
ports to monitor operating pressures during and at
completion of the procedure. Attach recovery system or
vacuum pump to gauge set as needed for the service
procedure. The service valves must be open to evacuate the
unit through the line set service ports. The suction capillary
service port is a direct connection to the suction port of the
compressor and may also be used.
2. Begin evacuation or refrigerant. Allow extra time for
refrigerant recovery and establishing a thorough evacuation.
Evacuation and recovery of refrigerant from 189BNV
1. Connect gauges to 189BNV liquid and vapor service valve
ports to monitor operating pressures during and at completion of the procedure. Attach recovery system or vacuum
pump to gauge set as needed for the service procedure. The
service valves must be open to evacuate the unit through the
line set service ports.
Evacuation and recovery of refrigerant from 189BNV
when using non-- communicating thermostat
1. Connect gauges to 189BNV liquid and vapor service valve
ports to monitor operating pressures during and at
completion of the procedure. Attach recovery system or
vacuum pump to gauge set as needed for the service
procedure. The service valves must be open to evacuate the
unit through the line set service ports.
Reversing Valve
In heat pumps, changeover between heating and cooling modes is
accomplished with a valve that reverses flow of refrigerant in
system. This reversing valve device is easy to troubleshoot and
replace. The reversing valve solenoid can be checked with power
off with an ohmmeter. Check for continuity and shorting to
ground. With control circuit (24v) power on, check for correct
voltage at solenoid coil. Check for overheated solenoid.
With unit operating, other items can be checked, such as frost or
condensate water on refrigerant lines.
The sound made by a reversing valve as it begins or ends defrost is
a “whooshing” sound, as the valve reverses and pressures in system
equalize. An experienced service technician detects this sound and
uses it as a valuable troubleshooting tool.
Using a remote measuring device, check inlet and outlet line
temperatures. DO NOT touch lines. If reversing valve is operating
normally, inlet and outlet temperatures on appropriate lines should
be close to each other. Any difference would be due to heat loss or
gain across valve body. Temperatures are best checked with a
remote reading electronic--type thermometer with multiple probes.
Route thermocouple leads to inside of coil area through service
valve mounting plate area underneath coil. Fig. 48 and Fig. 49
show test points (TP) on reversing valve for recording
temperatures. Insulate points for more accurate reading.
If valve is defective:
1. Shut off all power to unit and remove charge from system.
2. Remove solenoid coil from valve body. Remove valve by
cutting it from system with tubing cutter. Repair person
should cut in such a way that stubs can be easily re--brazed
back into system. Do not use hacksaw. This introduces
chips into system that cause failure. After defective valve is
removed, wrap it in wet rag and carefully unbraze stubs.
Save stubs for future use. Because defective valve is not
overheated, it can be analyzed for cause of failure when it is
returned.
3. Braze new valve onto used stubs. Keep stubs oriented
correctly. Scratch corresponding matching marks on old
valve and stubs and on new valve body to aid in lining up
new valve properly. When brazing stubs into valve, protect
valve body with wet rag to prevent overheating.
4. Use slip couplings to install new valve with stubs back into
system. Even if stubs are long, wrap valve with a wet rag to
prevent overheating.
5. After valve is brazed in, check for leaks. Evacuate and
charge system. Operate system in both modes several times
to be sure valve functions properly.
41
FROM INDOOR COIL VIA
SERVICE VALVE ON
OUTDOOR COIL
TO OUTDOOR
COIL
TO
ACCUMULATOR
TP--4
TP--3
!
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
To avoid filter drier damage while brazing, filter drier must be
wrapped in a heat--sinking material such as a wet cloth.
TP--2
Install Liquid--line Filter Drier Indoor
Install filter drier as follows:
1.
2.
3.
4.
TP--1
FROM COMPRESSOR
DISCHARGE LINE
Braze 5 in. liquid tube to the indoor coil.
Wrap filter drier with damp cloth.
Braze filter drier to 5 in. long liquid tube from step 1.
Connect and braze liquid refrigerant tube to the filter drier.
Suction Line Filter Drier
A88342
Fig. 48 – Reversing Valve
(Cooling Mode or Defrost Mode, Solenoid Energized)
FROM
OUTDOOR
COIL
TP--4
TO
ACCUMULATOR
TO INDOOR COIL
VIA SERVICE VALVE
ON OUTDOOR COIL
INSULATE
FOR
ACCURATE
READING
TP--3
INSULATE FOR
ACCURATE
READING
Thermostatic Expansion Valve (TXV)
TP--2
TP--1
FROM COMPRESSOR
DISCHARGE LINE
ELECTRONIC
THERMOMETER
A88341
Fig. 49 – Reversing Valve
(Heating Mode, Solenoid De--Energized)
Liquid Line Filter Drier
Filter driers are specifically designed for R--22 or Puronr
refrigerant. Only operate with the appropriate drier using factory
authorized components.
It is recommended that the liquid line drier be installed at the
indoor unit. Placing the drier near the TXV allows additional
protection to the TXV as the liquid line drier also acts as a strainer.
!
The suction line drier is specifically designed to operate with
Puronr, use only factory authorized components. Suction line filter
drier is used in cases where acid might occur, such as burnout. Heat
pump units must have the drier installed between the compressor
and accumulator only. Remove after 10 hours of operation. Never
leave suction line filter drier in a system longer than 72 hours
(actual time).
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
To avoid performance loss and compressor failure, installation
of filter drier in liquid line is required.
All fan coils and furnace coils will have a factory installed
thermostatic expansion valve (TXV). The TXV will be a bi--flow,
hard--shutoff with an external equalizer and a balance port pin. A
hard shut--off TXV does not have a bleed port. Therefore,
minimal equalization takes place after shutdown. TXVs are
specifically designed to operate with Puronr or R--22 refrigerant,
use only factory authorized TXV’s. Do not interchange Puron
and R--22 TXVs.
TXV Operation
The TXV is a metering device that is used in air conditioning and
heat pump systems to adjust to changing load conditions by
maintaining a preset superheat temperature at the outlet of the
evaporator coil. The volume of refrigerant metered through the
valve seat is dependent upon the following:
1. Superheat temperature is sensed by cap tube sensing bulb
on suction tube at outlet of evaporator coil. This
temperature is converted into pressure by refrigerant in the
bulb pushing downward on the diaphragm which opens the
valve via the push rods.
2. The suction pressure at the outlet of the evaporator coil is
transferred via the external equalizer tube to the underside
of the diaphragm. This is needed to account for the indoor
coil pressure drop. Residential coils typically have a high
pressure drop, which requires this valve feature.
3. The pin is spring loaded, which exerts pressure on the
underside of the diaphragm. Therefore, the bulb pressure
works against the spring pressure and evaporator suction
pressure to open the valve.
If the load increases, the temperature increases at the bulb,
which increases the pressure on the top side of the
diaphragm. This opens the valve and increases the flow of
refrigerant. The increased refrigerant flow causes the
leaving evaporator temperature to decrease. This lowers the
pressure on the diaphragm and closes the pin. The
refrigerant flow is effectively stabilized to the load demand
with negligible change in superheat.
42
Accumulator
The accumulator is specifically designed to operate with Puronr
or R22 respectfully; use only factory--authorized components.
Under some light load conditions on indoor coils, liquid refrigerant
is present in suction gas returning to compressor. The accumulator
stores liquid and allows it to boil off into a vapor so it can be safely
returned to compressor. Since a compressor is designed to pump
refrigerant in its gaseous state, introduction of liquid into it could
cause severe damage or total failure of compressor.
The accumulator is a passive device which seldom needs replacing.
Occasionally its internal oil return orifice or bleed hole may
become plugged. Some oil is contained in refrigerant returning to
compressor. It cannot boil off in accumulator with liquid
refrigerant. The bleed hole allows a small amount of oil and
refrigerant to enter the return line where velocity of refrigerant
returns it to compressor. If bleed hole plugs, oil is trapped in
accumulator, and compressor will eventually fail from lack of
lubrication. If bleed hole is plugged, accumulator must be changed.
The accumulator has a fusible element located in the bottom end
bell. (See Fig. 50.) This fusible element will melt at 430_F//221_C
and vent the refrigerant if this temperature is reached either internal
or external to the system. If fuse melts, the accumulator must be
replaced.
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing, modifying, or servicing system, main
electrical disconnect switch must be in the OFF position.
There may be more than 1 disconnect switch. Lock out and
tag switch with a suitable warning label.
REFRIGERATION SYSTEM
REPAIR
Leak Detection
New installations should be checked for leaks prior to complete
charging. If a system has lost all or most of its charge, system must
be pressurized again to approximately 150 psi minimum and 375
psi maximum. This can be done by adding refrigerant using
normal charging procedures or by pressurizing system with
nitrogen (less expensive than refrigerant). Nitrogen also leaks faster
than refrigerants. Nitrogen cannot, however, be detected by an
electronic leak detector. (See Fig. 51.)
BEEP
BEEP
430° FUSE
ELEMENT
A95422
Fig. 51 – Electronic Leak Detection
A88410
Fig. 50 – Accumulator
To change accumulator:
1. Shut off all power to unit.
2. Recover all refrigerant from system.
3. Break vacuum with dry nitrogen. Do not exceed 5 psig.
NOTE: Coil may be removed for access to accumulator. Refer to
appropriate sections of Service Manual for instructions.
!
CAUTION
PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal injury.
Wear safety glasses, protective clothing, and gloves when
handling refrigerant.
4. Remove accumulator from system with tubing cutter.
5. Tape ends of open tubing.
6. Scratch matching marks on tubing studs and old
accumulator. Scratch matching marks on new accumulator.
Unbraze stubs from old accumulator and braze into new
accumulator.
7. Thoroughly rinse any flux residue from joints and paint
with corrosion--resistant coating such as zinc--rich paint.
8. Install factory authorized accumulator into system with
copper slip couplings.
9. Evacuate and charge system.
Pour and measure oil quantity (if any) from old accumulator. If
more than 20 percent of oil charge is trapped in accumulator, add
new POE oil to compressor to make up for this loss.
!
PERSONAL
HAZARD
WARNING
INJURY
AND
UNIT
DAMAGE
Failure to follow this warning could result in personal
injury or death.
Due to the high pressure of nitrogen, it should never be
used without a pressure regulator on the tank.
Assuming that a system is pressurized with either all refrigerant or
a mixture of nitrogen and refrigerant, leaks in the system can be
found with an electronic leak detector that is capable of detecting
specific refrigerants.
If system has been operating for some time, first check for a leak
visually. Since refrigerant carries a small quantity of oil, traces of
oil at any joint or connection is an indication that refrigerant is
leaking at that point.
A simple and inexpensive method of testing for leaks is to use soap
bubbles. (See Fig. 52.) Any solution of water and soap may be
used. Soap solution is applied to all joints and connections in
system. A small pinhole leak is located by tracing bubbles in soap
solution around leak. If the leak is very small, several minutes may
pass before a bubble will form. Popular commercial leak detection
solutions give better, longer--lasting bubbles and more accurate
results than plain soapy water. The bubble solution must be
removed from the tubing and fittings after checking for leaks as
some solutions may corrode the metal.
43
Coil Removal
LEAK
DETECTOR
SOLUTION
A95423
Fig. 52 – Bubble Leak Detection
You may use an electronic leak detector designed for specific
refrigerant to check for leaks. (See Fig. 51.) This unquestionably is
the most efficient and easiest method for checking leaks. There are
various types of electronic leak detectors. Check with manufacturer
of equipment for suitability. Generally speaking, they are portable,
lightweight, and consist of a box with several switches and a probe
or sniffer. Detector is turned on and probe is passed around all
fittings and connections in system. Leak is detected by either the
movement of a pointer on detector dial, a buzzing sound, or a light.
In all instances when a leak is found, system charge must be
recovered and leak repaired before final charging and operation.
After leak testing or leak is repaired, replace liquid line filter drier,
evacuate system, and recharge with correct refrigerant quantity.
!
WARNING
Coils are easy to remove if required for compressor removal, or to
replace coil.
1. Shut off all power to unit.
2. Recover refrigerant from system through service valves.
3. Break vacuum with nitrogen.
4. Remove top cover.
5. Remove screws in base pan to coil grille.
6. Remove coil grille from unit.
7. Remove screws on corner post holding coil tube sheet.
!
WARNING
FIRE HAZARD
Failure to follow this warning could result in personal
injury or equipment damage.
Cut tubing to reduce possibility of personal injury and fire.
8. Use midget tubing cutter to cut liquid and vapor lines at
both sides of coil. Cut in convenient location for easy
reassembly with copper slip couplings.
9. Lift coil vertically from basepan and carefully place aside.
10. Reverse procedure to reinstall coil.
11. Replace filter drier, evacuate system, recharge, and check
for normal systems operation.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing, modifying, or servicing system, main
electrical disconnect switch must be in the OFF position.
There may be more than 1 disconnect switch. Lock out and
tag switch with a suitable warning label.
E 2017 Bryant Heating & Cooling Systems 7310 W. Morris St. Indianapolis, IN 46231
Edition Date: 01/17
Catalog No. SM288BNV ---189BNV ---04
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
44
Replaces: SM288BNV--- 189BNV--- 03
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