York | SUNLINE 2000 B5CH 036 | Operating instructions | York SUNLINE 2000 B5CH 036 Operating instructions

®
SUNLINE 2000
GAS / ELECTRIC
SINGLE PACKAGE AIR CONDITIONERS
INSTALLATION INSTRUCTION
530.18-N8Y (295)
Supersedes: 530.18-N8Y (994)
MODELS D6CG 036, 048 & 060 (10 SEER)
MODEL D1CG 072 (9 EER)
(STYLE A & Belt Drive Option)
035-12857
GENERAL
YORK Model DCG units are single package air conditioners
with gas heat designed for outdoor installation on a rooftop or
a slab.
The units are completely assembled on rigid, permanently
attached base rails. All piping, refrigerant charge, and electrical
wiring is factory-installed and tested. The units require only
electric power, gas piping and duct connections at the point of
installation.
The gas-fired heaters have aluminized steel tubular heat
exchangers and spark ignition with intermittent pilot.
This appliance is not to be used for temporary heating of
buildings or structures under construction.
INSPECTION
•
•
•
•
•
•
•
•
530.18-N1.6V
530.18-N1.8V
530.18-N2.11V
530.18-N8.2V
530.18-N8.3V
530.18-N8.4V
530.18-N8.12V
690.15-N25V
Renewal Parts:
-Motorized Outdoor Air Damper Accy.
-Coil Guard
-Low NOx Accessory
-High Altitude Accy. (Natural Gas)
-High Altitude Accy. (Propane)
-Gas Piping Accessory
-Propane Conversion Accessor
-Low Ambient Accessory
• Refer to Parts Manual for complete listing of replacement
parts on this equipment.
All forms referenced in this instruction may be ordered from:
As soon as a unit is received, it should be inspected for possible
damage during transit. If damage is evident, the extent of the
damage should be noted on the carrier’s freight bill. A separate
request for inspection by the carrier’s agent should be made in
writing. Refer to Form 50.15-NM for additional information.
APPROVALS
REFERENCE
Design certified by CGA and UL listed as follows:
Additional information on the design, installation, operation and
service of this equipment is available in the following reference forms:
1. For use as a forced air furnace with cooling unit.
2. For outdoor installation only.
3. For installation directly on combustible flooring or, in the U.S.A.,
on wood flooring or Class A, B, or C roof covering material.
4. For use with natural gas and/or propane (LP) gas.
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55.70-N1
-General Installation
55.70-N2
-Pre-start & Post-start Check List
530.18-N1.2V -Economizer Accessory
530.18-N1.4V -Fixed Outdoor Air Damper Accessory
Publications Distribution Center
Unitary Products Group
P.O. Box 1592, York, PA 17405
Not suitable for use with conventional venting systems.
Installer should pay particular attention to the words: NOTE, CAUTION and WARNING. Notes are intended to clarify or
make the installation easier. Cautions are given to prevent equipment damage. Warnings are given to alert installer that personal injury and/or equipment damage may result if installation procedure is not handled properly.
FOR YOUR SAFETY
If you smell gas:
1. Open windows
2. Don’t touch
electrical switches.
3. Extinguish any
open flame.
4. Immediately call
your gas supplier.
FOR YOUR SAFETY
Do not store or use
gasoline or other
flammable vapors or
liquids in the vicinity
of this or any other
appliance.
CAUTION
THIS PRODUCT M UST BE INSTALLED IN STRICT COMPLIANCE W ITH
THE ENCLOSED INSTALLATION INSTRUCTIONS AND ANY APPLICABLE
LOCAL, STATE, AND NATIONAL CODES INCLUDING, BUT NOT LIMITED
TO, BUILDING, ELECTRICAL, AND MECHANICAL CODES.
WARNING
INCORRECT INSTALLATION MAY CREATE A CONDITION WHERE THE
OPERATION OF THE PRODUCT COULD CAUSE PERSONAL INJURY
OR PROPERTY DAMAGE.
530.18-N8Y
TABLE OF CONTENTS
Burner Instructions............................................................. 15
Burner Air Shutter Adjustment ........................................... 15
Supply Air Blower and Temperature Rise Adjustment ....... 15
Checking Gas Input ........................................................... 16
Secure Owner’s Approval .................................................. 16
General ................................................................................ 1
Inspection............................................................................. 1
Reference ............................................................................ 1
Approvals ............................................................................. 1
Nomenclature....................................................................... 2
INSTALLATION
MAINTENANCE & TROUBLESHOOTING
Limitations............................................................................ 3
Location ............................................................................... 3
Rigging and Handling .......................................................... 3
Clearances........................................................................... 3
Ductwork .............................................................................. 3
Filters ................................................................................... 4
Condensate Drain ................................................................ 4
Service Access..................................................................... 4
Thermostat ........................................................................... 4
Power and Control Wiring.................................................... 4
Blower Speed Selection....................................................... 4
Compressors........................................................................ 4
Combustion Discharge ........................................................ 4
Disconnect Switch Bracket For Optional Belt-Drive ............ 5
Gas Piping ........................................................................... 5
Gas Connection ................................................................... 6
L.P. Units, Tanks and Piping ................................................ 6
Low NOx Application............................................................ 6
Vent and Combustion Air Hoods.......................................... 7
Optional Economizer Rain Hood ......................................... 7
Normal Maintenance.......................................................... 16
Cleaning Flue Passages and Heating Elements ............... 17
Troubleshooting ................................................................. 17
TABLES
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Description
Page
Unit Application Data ..................................
3
Gas Heat Application Data..........................
4
Pipe Sizing .................................................
5
Physical Data..............................................
8
Supply Air Blower Perf. 3 - 6 Ton Direct-Drive
8
Supply Air Blower Perf. 3 & 4 Ton Belt-Drive 9
Supply Air Blower Perf. 5 & 6 Ton Belt-Drive 10
Accessory Static Resistances .................... 12
Motor & Drive Data-Belt-Drive Blower........ 12
Electrical Data Direct-Drive ........................ 12
Electrical Data Belt-Drive............................ 12
Limit Control Setting ................................... 14
Belt Drive Supply Air Motor Pulley Adj........ 15
Gas Rate - Cubic Feet Per Hour ................ 16
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Description
Page
Center of Gravity.........................................
3
Recommended Drain Piping.......................
4
Typical Field Wiring.....................................
5
External Supply Connection .......................
6
Bottom Supply Connection .........................
6
Vent and Combustion Air Hoods.................
7
Economizer Rain Hood Assembly ..............
7
Enthalpy Setpoint Adjustment.....................
8
Dimensions and Clearances....................... 11
Gas Valve Piping......................................... 13
Gas Valves.................................................. 14
Proper Flame Adjustment ........................... 15
Typical Flame Appearance ......................... 15
Hole Loc. for Press. Drop Readings........... 15
Press. Drop versus Supply Air CFM ........... 16
OPERATION
FIGURES
Cooling System.................................................................. 13
Preliminary Operation Cooling........................................... 13
Cooling Sequence of Operation ........................................ 13
Safty Controls (Cooling)..................................................... 13
Heating Sequence of Operation ........................................ 13
Safety Controls (Heating) .................................................. 14
Heat Anticipator Setpoints ................................................. 14
Pre-Start Check List........................................................... 14
START-UP
Operating Instructions........................................................ 14
Post-Start Check List (Gas) ............................................... 14
Manifold Gas Pressure Adjustment ................................... 14
Pilot Checkout.................................................................... 15
PRODUCT NOMENCLATURE
D
6
C
G
0
3
6
N
0
4
0
2
PRODUCT CATEGORY
D = Single Package Air Conditioner
(Air Cooled)
5
VOLTAGE CODE
06 = 208/230-1-60
25 = 208/230-3-60
46 = 460-3-60
58 = 575-3-60
PRODUCT GENERATION
NOMINAL GAS HEATING
OUTPUT CAPACITY
1 = 1st Generation
6 = 6th Generation
PRODUCT IDENTIFIER
CG = Gas/Electric
NOMINAL COOLING
CAPACITY
036 = 3 Ton
048 = 4 Ton
060 = 5 Ton
072 = 6 Ton
2
FACTORY INSTALLED
HEAT
040 = 40 MBH
060 = 60 MBH
079 = 79 MBH
099 = 99 MBH
N = Gas Heat Installed
Unitary Products Group
530.18-N8Y
INSTALLATION
LIMITATIONS
These units must be installed in accordance with the current
editions of the following national and local safety codes:
In the U.S.A.:
1. National Electrical Code ANSI/NFPA No. 70.
2. National Fuel Gas Code Z223.1.
3. Gas-Fired Central Furnace Standard ANSI Z21.47-1993.
4. Local gas utility requirements.
In Canada:
1. Canadian Electrical Code CSA C22.1
2. Current Gas Installation Codes CAN/CGA-2.3-M93.
3. Local plumbing and waste water codes.
4. Other applicable local codes.
Refer to Table 1 for Unit Application Data and to Table 2 for Gas
Heat Application Data.
If components are to be added to a unit to meet local codes, they
are to be installed at the dealer’s and / or the customer’s expense.
Size of unit for proposed installation should be based on heat
loss / heat gain calculation made according to the methods of
Air Conditioning Contractors of America (ACCA).
TABLE 1 - UNIT APPLICATION DATA
Model DCG
036
048
060
072
208/230V
187 / 253
Voltage Variation
460V
414 / 504
Min. / Max.1
575V
518/630
Supply Air CFM, Nom.
1200
1600
2000
2400
Wet Bulb Temperature (°F) of
57 / 72 57 / 72 57 / 72 57 / 72
Air on Evaporator Coil,
Min. / Max.
Dry Bulb Temperature (°F) of
45 / 120 45 / 120 45 / 120 45 / 120
Air on Condenser Coil,
Min.2 / Max.
1
Utilization range “A” in accordance with ARI Standard 110.
2
A low ambient accessory is available for operation down to 0°F.
LOCATION
Use the following guidelines to select a suitable location for
these units.
CAUTION: If a unit is to be installed on a roof curb or special
frame other than a YORK roof curb, gasketing must
be applied to all surfaces that come in contact with
the unit underside.
5. Maintain level tolerance to 1/2" maximum across the entire
length or width of the unit.
6. Elevate the unit sufficiently to prevent any blockage of the
air entrances by snow in areas where there will be snow
accumulation. Check the local weather bureau for the
expected snow accumulation in your area.
RIGGING AND HANDLING
Exercise care when moving the unit. Do not remove any
packaging until the unit is near the place of installation. Rig the
unit by attaching chain or cable slings to the lifting holes
provided in the base rails. Spreaders, whose length exceeds
the largest dimension across the unit, MUST be used across
the top of the unit.
BEFORE LIFTING A UNIT, MAKE SURE THAT ITS WEIGHT
IS DISTRIBUTED EQUALLY ON THE CABLES SO THAT IT
WILL LIFT EVENLY.
Units may also be moved or lifted with a forklift. Slotted
openings in the base rails are provided for this purpose.
LENGTH OF FORKS MUST BE A MINIMUM OF 42".
Remove the nesting brackets from the four corners on top of
the unit. All screws that are removed when taking these
brackets off must be replaced on the unit.
CAUTION: An adhesive backed label is provided over the
outside of the combustion air inlet opening to prevent moisture from entering the unit which could
cause damage to electrical components. Allow this
closure label to remain in place until the combustion air hood is to be installed (refer to Figure 6).
Refer to Table 4 for unit weights and to Figure 1 for approximate
center of gravity.
CONDENSER
COIL END
BACK
APPROXIMATE
CENTER OF
GRAVITY
FRONT
32-1/8
447⁄8“
15-1/4
A
B
21
1. Unit is designed for outdoor installation only.
2. Condenser coils must have an unlimited supply of air.
Where a choice of location is possible, position the unit on
either north or east side of building.
WARNING: Excessive exposure of this furnace to contaminated combustion air may result equipment damage or personal injury. Typical contaminates
include: permanent wave solutions, chlorinated
waxes and cleaners, chlorine based swimming
pool chemicals, water softening chemicals, carbon
tetrachloride, Halogen type refrigerants, cleaning
solvents (e.g. perchloroethylene), printing inks,
paint removers, varnishes, hydrochloric acid, cements and glues, antistatic fabric softeners for
clothes dryers, masonry acid washing materials.
3. For ground level installation, use a level concrete slab with
a minimum thickness of 4 inches. The length and width
should be at least 6 inches greater than the unit base rails.
Do not tie slab to the building foundation.
4. Roof structures must be able to support the weight of the unit
and its options and / or accessories. Unit must be installed on
a solid level roof curb or appropriate angle iron frame.
Unitary Products Group
FIG. 1 - CENTER OF GRAVITY
48-11/32
821⁄4“
DIM.
A
B
3-5 TON 6 TON
19-3/4"
22"
40-3/4"
44"
CLEARANCES
All units require certain clearances for proper operation and
service. Installer must make provisions for adequate combustion
and ventilation air in accordance with Section 5.3, Air for
Combustion and Ventilation of the National Fuel Gas Code, ANSI
Z223.1 (in U.S.A.) or Sections 7.2, 7.3 or 7.4 of Gas Installation
Codes CAN/CGA-B149.1 and .2 (in Canada) and/or applicable
provisions of the local building codes. Refer to Figure 9 for the
clearances required for combustible construction, servicing,
and proper unit operation.
WARNING: Do not permit overhanging structures or shrubs to
obstruct condenser air discharge outlet, combustion
air inlet or vent outlet.
DUCTWORK
Ductwork should be designed and sized according to the methods
in Manual Q of the Air Conditioning Contractors of America (ACCA).
A closed return duct system shall be used. This shall not preclude
use of economizers or outdoor fresh air intake. The supply and
return air duct connections at the unit should be made with flexible
joints to minimize the transmission of noise.
3
530.18-N8Y
The supply and return air duct systems should be designed for the
CFM and static requirements of the job. They should NOT be sized
to match the dimensions of the duct connections on the unit.
CAUTION: When fastening ductwork to the side duct flanges on
the unit, insert the screws through the duct flanges
only. DO NOT insert the screws through the casing.
Outdoor ductwork must be insulated and waterproofed.
Refer to Figure 9 for information concerning side and bottom
supply and return air duct openings.
FILTERS
1" filters are supplied with each unit. 2" replacement filters may
be used with no modification to the filter racks. Filters must
always be installed ahead of the evaporator coil and must be
kept clean or replaced with same size and type. Dirty filters will
reduce the capacity of the unit and will result in frosted coils or
safety shutdown. Minimum filter area and required sizes are
shown in Table 4.
CONDENSATE DRAIN
Plumbing must conform to local codes. Use a sealing compound
on male pipe threads. Install a condensate drain line from the 3/4"
PVC female connection on the unit to spill into an open drain.
NOTE: The condensate drain line MUST be trapped to provide
proper drainage. See Figure 2.
Canadian Electric Code (CEC) C22.1 (in Canada), and / or
local ordinances. The unit must be electrically grounded in
accordance with the N.E.C. ANSI / NFPA 70 or local codes.
Voltage tolerances which must be maintained at the
compressor terminals during start-up and running conditions
are indicated on the unit Rating Plate and Table 1.
The internal wiring harness furnished with this unit is an integral
part of a UL and CGA design certified unit. Field alteration to
comply with electrical codes should not be required.
A disconnect switch should be field provided for the unit. The
switch must be separate from all other circuits. Refer to Figure
9 for installation location. If any of the wire supplied with the
unit must be replaced, replacement wire must be of the type
shown on the wiring diagram.
Electrical lines must be sized properly to carry the load. USE COPPER
CONDUCTORS ONLY. Each unit must be wired with a separate
branch circuit fed directly from the meter panel and properly protected.
CAUTION: When connecting electrical power and control wiring to the unit, waterproof type connectors MUST
BE USED so that water or moisture cannot be
drawn into the unit during normal operation. The
above waterproofing conditions will also apply
when installing a field-supplied disconnect switch.
Refer to Figure 3 for typical field wiring and to the appropriate unit
wiring diagram for control circuit and power wiring information.
BLOWER SPEED SELECTION
FIG. 2 - RECOMMENDED DRAIN PIPING
SERVICE ACCESS
Access to all serviceable components is provided by the
following removable panels:
•
•
•
•
•
•
Compressor compartment
Burner compartment
Blower compartment
Main control box
Filter compartment
Motor access (on units with belt-drive option)
Refer to Figure 9 for location of these access panels.
Three blower motor speeds are available on the direct-drive
units. The speed selection for the direct-drive units is
determined by the CFM and ESP requirements of the
applications. All units with belt-drive option have an adjustable
motor pulley to achieve the above conditions.
All direct-drive units with 208/230 voltage are shipped with the
wire labeled #116 connected to the "HIGH" speed tap on the
blower motor. If a lower blower motor speed is desired, this wire
should be moved to the "MED" or "LOW" speed tap on the
motor for the speed desired.
All direct-drive units with 460 and 575 voltage are shipped with
the wire labeled #116 connected to the "HIGH" speed tap on
the blower motor. If the medium speed is required, connect wire
#116 to the "MED" speed tap and the blue motor lead to the
"HIGH" speed tap. If the low speed is required, connect wire
#116 to the "LOW" speed tap, the blue motor lead to the "HIGH"
speed tap and the orange motor lead to the "MED" speed tap.
COMPRESSORS
On some units the compressor is mounted on springs which
have been tightened down for shipment only.
After this unit is installed, back out the compressor bolts until
the sleeve clears the top grommet.
CAUTION: Make sure that all screws are replaced on the unit
to maintain an air-tight seal.
CAUTION: Do Not loosen compressor mounting bolts.
THERMOSTAT
TABLE 2 - GAS HEAT APPLICATION DATA
Input
Capacity,
(Mbh)
50
75
100
125
The room thermostat should be located on an inside wall
approximately 56" above the floor where it will not be subject
to drafts, sun exposure, or heat from electrical fixtures or
appliances. Follow manufacturer’s instructions enclosed with
thermostat for general installation procedure. Color coded
insulated wires (#18 AWG) should be used to connect
thermostat to unit. See figure 3 for wiring details.
NOTE: If the unit has an economizer, remove jumper J1 from
terminals 8 and 10 on the relay board to prevent
simultaneous operation of the compressor and the
economizer. If you want to energize the compressor
for supplemental cooling during the economizer operation, use a thermostat with two stages of cooling.
POWER AND CONTROL WIRING
Field wiring to the unit must conform to provisions of the National
Electrical Code (NEC), ANSI / NFPA 70-1987 (in USA) current
4
Output
Capacity,
(Mbh)
40
60
79
99
Temp. Rise °F
Available
Gas Rate1
At Full Input 2
on
(Ft.3/Hr.)
Models
Min.
Max.
3 Ton
47
15
45
4 Ton
70
25
55
3/5/6 Ton
93
40/25/25 70/55/55
4/5/6 Ton
116
45/35/35 75/65/65
NOTE: Gas Heaters are shipped available for natural gas, but can be converted to L.P. with Kit Model
No. 1NP0434. All furnaces meet the latest California seasonal efficiency requirements.
1
Based on 1075 Btu/Ft3.
2
The air flow must be adjusted to obtain a temperature rise within the range shown.
COMBUSTION DISCHARGE
The products of combustion are discharged horizontally
through a screened opening on the gas heat access panel.
Unitary Products Group
530.18-N8Y
COOLING / HEATING (24 VOLT THERMOSTAT)
CONTROL WIRING
COOLING / HEATING (24 VOLT ELECTRONIC THERMOSTAT)
THERMOSTAT1
TERMINALS
UNIT TERMINAL
STRIP TB1
THERMOSTAT1
TERMINALS
ADD
JUMPER
ADD
JUMPER
3
4
NOT
USED
ADD
JUMPER
COOLING / HEATING (24 VOLT ELECTRONIC THERMOSTAT)
1
UNIT TERMINAL
STRIP TB1
ADD
JUMPER
4
TO REMOTE SENSOR
2TH04702224 IF USED
24 VOLT THERMOSTAT 2TH07701024. IF THE UNIT HAS AN ECONOMIZER,
REMOVE JUMPER J1 FROM TERMINALS 8 AND 10 ON THE RELAY BOARD
TO PREVENT SIMULTANEOUS OPERATION OF THE COMPRESSOR AND
THE ECONOMIZER. IF YOU WANT TO CONTROL THE ECONOMIZER ON A
SECOND STAGE OF COOLING OR HAVE AN ELECTRIC HEAT ACCESSORY
WITH TWO STAGES OF HEAT, USE THERMOSTAT 2TH04701024.
THERMOSTAT
TERMINALS
24 VOLT
TRANSFORMER
2
24 VOLT
TRANSFORMER
1
UNIT TERMINAL
STRIP TB1
1
1
ELECTRONIC PROGRAMMABLE THERMOSTAT 2ET04700224 (INCLUDES SUBBASE)
TO CONTROL ECONOMIZER ON SECOND STAGE OF COOLING, REMOVE JUMPER
J1 FROM TERMINALS 8 AND 10 ON THE RELAY BOARD.
2
SECOND STAGE COOLING IS NOT REQUIRED ON UNITS LESS ECONOMIZER.
3
SECOND STAGE HEATING IS ONLY REQUIRED ON UNITS WITH A TWO STAGE
ELECTRIC HEATER.
4
REMOVE JUMPER J2 FROM TERMINALS 4 AND 9 ON JUMPER PLUG CONNECTOR
P6 ON UNITS WITH ECONOMIZER. TERMINALS A1 AND A2 PROVIDE A RELAY
OUT-PUT TO CLOSE THE OUTDOOR ECONOMIZER DAMPERS WHEN THE
THERMOSTAT SWITCHES TO THE SET-BACK POSITION.
ELECTRONIC PROGRAMMABLE THERMOSTAT 2ET07701024 (INCLUDES SUBBASE).
IF THIS UNIT HAS AN ECONOMIZER, REMOVE JUMPER J1 FROM TERMINALS 8 AND
10 ON THE RELAY BOARD TO PREVENT SIMULTANEOUS OPERATION OF THE
COMPRESSOR AND THE ECONOMIZER. IF YOU WANT TO CONTROL THE
ECONOMIZER ON A SECOND STAGE OF COOLING, USE THERMOSTAT 2ET04700224.
24 VOLT
TRANSFORMER
CAUTION: Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and
dangerous operation. Verify proper operation after
servicing.
POWER WIRING
RE FER TO ELECTR ICAL DATA
TABLES TO SIZE THE DISCONNECT
SWITCH, WIRING & OVERCURRENT
PROTECTION.
FIG. 3 - TYPICAL FIELD WIRING
DISCONNECT SWITCH BRACKET FOR UNITS
WITH OPTIONAL BELT-DRIVE BLOWER
A special bracket for mounting a field-supplied disconnect
switch is provided in each unit ordered with an optional
belt-drive supply air blower. The bracket is shipped inside the
blower compartment taped to the top of the blower housing.
Install the bracket on the left hand side of the unit as shown in
Figure 9. Several existing screws at the top of the unit and one
screw approximately midway down from the top will be used
for mounting the bracket. Screws should be loosened only NOT REMOVED. Matching holes in the bracket have
elongated keyways allowing easy installation. Re-tighten
screws after bracket is in place to ensure panels will remain
leak tight.
GAS PIPING
Proper sizing of gas piping depends on the cubic feet per hour
of gas flow required, specific gravity of the gas and the length
of run. “National Fuel Gas Code” Z223-1992 (in the USA), or
Unitary Products Group
R EFER TO EL EC TRIC AL DATA
TABLES TO SIZE THE DISCONNECT
SWITCH, WIRING & OVERCURRENT
PROTECTION.
the current Gas Installation Codes CAN/CGA-B149.1 and .2
(in Canada) should be followed in all cases unless superseded
by local codes or gas company requirements. Refer to Table 3.
TABLE 3 - PIPE SIZING
Length in Feet
10
20
30
40
50
60
70
80
90
100
1/2 in.
132
92
73
63
56
50
46
43
40
38
Nominal Iron Pipe Size
3/4 in.
1 in.
278
520
190
350
152
285
130
245
115
215
105
195
96
180
90
170
84
160
79
150
1-1/4 in.
1,050
730
590
500
440
400
370
350
320
305
Maximum capacity of pipe in cubic feet of gas per hour. (Based upon a pressure drop of 0.3
inch water column and 0.6 specific gravity gas).
5
530.18-N8Y
FIG. 4 - EXTERNAL SUPPLY CONNECTION
EXTERNAL SHUT-OFF
FIG. 5 - BOTTOM SUPPLY CONNECTION
EXTERNAL SHUT-OFF
The heating value of the gas may differ with locality. The value
should be checked with the local gas utility.
6. The furnace and its individual manual shut-off valve must
be disconnected from the gas supply piping system during
any pressure testing of that system at test pressures in
excess of 1/2 psig (3.48kPa).
NOTE: There may be a local gas utility requirement specifying
a minimum diameter for gas piping. All units require a
1/2 inch pipe connection at the entrance fitting.
GAS CONNECTION
The gas supply line can be routed through the knockouts
located on the front of the unit or through the opening provided
in the unit’s base. Refer to Figure 9 to locate these access
openings. Typical supply piping arrangements are shown in
Figures 4 and 5. All shaded items are field-supplied.
Two grommets are shipped in the blower compartment (in parts
bag taped to the blower housing) of every unit with gas heat
and should be used in the knockouts when the gas piping
penetrates the front of the unit.
After the gas supply piping has been installed, the bottom
opening should be sealed to prevent water from leaking into
the building.
Gas piping recommendations:
1. A drip leg and a ground joint union must be installed in the
gas piping.
The furnace must be isolated from the gas supply piping
system by closing its individual manual shut-off valve
during any pressure testing of the gas supply piping system
at test pressures equal to or less than 1/2 psig (3.48kPa).
7. A 1/8 inch NPT plugged tapping, accessible for test gage
connection, must be installed immediately upstream of the
gas supply connection to the furnace.
L.P./PROPANE UNITS, TANKS AND PIPING
All gas heat units are shipped from the factory equipped for natural
gas use only. The unit may be converted in the field for use with
L.P./propane gas with accessory kit model number 1NP0434..
All L.P./propane gas equipment must conform to the safety
standards of the National Fire Protection Association.
For satisfactory operation, L.P./propane gas pressure must be
10.5 inch W.C at the unit under full load. Maintaining proper
gas pressure depends on three main factors:
2. When required by local codes, a manual shut-off valve may
have to be installed outside of the unit.
1. The vaporization rate which depends on (a) the
temperature of the liquid and (b) the “wetted surface” area
of the container or containers.
3. Use wrought iron or steel pipe for all gas lines. Pipe
compound should be applied sparingly to male threads
only.
2. The proper pressure regulation. (Two-stage regulation is
recommended from the standpoint of both cost and
efficiency.)
WARNING: Natural gas may contain some propane. Propane,
being an excellent solvent, will quickly dissolve
white lead or most standard commercial compounds. Therefore, a special pipe compound must
be applied when wrought iron or steel pipe is used.
Shellac base compounds such as Gaskolac or
Stalastic, and compounds such as Rectorseal #5,
Cyde’s or John Crane may be used.
3. The pressure drop in the lines between regulators and
between the second stage regualtor and the appliance.
Pipe size required will depend on the length of the pipe run
and the total load of all appliances.
4. All piping should be cleaned of dirt and scale by hammering
on the outside of the pipe and blowing out the loose dirt and
scale. Before initial start-up, be sure that all of the gas lines
external to the unit have been purged of air.
5. The gas supply should be a separate line and installed in
accordance with all safety codes as prescribed under
“Limitations”. After the gas connections have been
completed, open the main shut-off valve admitting normal
gas pressure to the mains. Check all joints for leaks with
soap solution or other material suitable for the purpose.
NEVER USE A FLAME.
6
Complete information regarding tank sizing for vaporization,
recommended regulator settings, and pipe sizing is available from
most regulator manufacturers and L.P./propane gas suppliers.
L.P./propane gas is an excellent solvent and special pipe
compound must be used when assembling piping for this gas
as it will quickly dissolve white lead or most standard
commercial compounds. Shellac base compunds such as
Rectorseal #5 are satisfactory for this type of gas.
Check all connections for leaks when piping is completed,
using a soap solution. NEVER USE A FLAME.
LOW NOx APPLICATION
For natural gas heat installations in locations which require low
Nitros Oxide emmissions, accessory model 1LN0404 must be
installed.
Unitary Products Group
530.18-N8Y
1. With filter section access panel removed, take out hood
components, filters and sensor described above. Remove
and discard outdoor air opening cover on back unit (Upper
right hand corner).
VENT AND COMBUSTION AIR HOODS
The vent and combustion air hoods are shipped attached to the
blower housing in the blower compartment. These hoods must
be installed on the outside of the gas heat access panel to
ensure proper unit function. The necessary mounting screws
are provided in a bag also attached to the blower housing.
The screen for the combustion air intake hood is secured to the
inside of the access panel opening with three fasteners and the
screws used for mounting the hood to the panel. The top flange
of this hood slips in under the top of the access panel opening
when installing. Refer to Figure 6. Remove the protective label
covering the opening just prior to installing this hood.
The vent hood (including its screen) is installed by inserting the
top flange of the hood into the slotted opening in the access
panel. The top screw secures the hood to the access panel.
The remaining two side screws must be installed after the
access panel is installed on the unit. These screws engage the
bottom flue box flange.
2. Remove the 1/2" knockout (A) in the units rear panel
(located to the right side of the outdoor air opening). Insert
the two loose wires from inside the unit, into the 1/2"
bushing provided. Insert wires and bushing into knockout.
Snap bushing into place.
3. Mount the outdoor air sensor to the rear panel, just below
the knockout described in Step 2. Secure with two
self-drilling screws at dimples (B) provided in the panel.
NOTE: Sensor must be positioned so that the sensing ports
are at the top (louvers pointing downward) and terminal connections to the right.
4. Connect the two wires, indicated in Step 2, to the sensor
as follows:
CAUTION: All three screws in the vent hood must be properly
installed before furnace operation to insure all
combustion products are exhausted from the unit.
• Wire #73 to terminal (+)
• Wire #74 to terminal (S)
5. Assemble the LH and RH side plates to the top cover (2
screws each side) to form the hood. Apply gasketing to the
flange surface on each side plate. Extend gasketing 1/4"
beyond top and bottom of each flange to insure adequate
corner sealing. Secure this assembly to the unit back panel
(upper right hand corner). First, remove screw (C) on unit
top cover. Then slip flange of hood cover in under flange of
unit top cover, replace screw (C), engaging hole (E) in hood
flange and tighten. Attach the two side plates to the unit
panel by using two self-drilling screws for each side plate
at dimples (D) provided in the panel.
FIG. 6 - VENT AND COMBUSTION AIR HOODS
OPTIONAL ECONOMIZER RAIN HOOD
6. Position fillpiece at bottom of hood, between the two side
plates but do not secure at this time. (Slotted openings MUST
be downward for drainage). After fillpiece is properly positioned, note where contact is made with the unit panel. Remove fillpiece and apply gasket material to this area to provide
a seal. Reposition fillpiece and secure with 2 screws.
The following procedure should be used when assembling an
economizer rain hood onto a unit. Refer to Figure 7. The
outdoor and return air dampers, damper actuator, the linkage
and all the controls are factory mounted as part of the
economizer option.
7. Install the two filters into the hood assembly, sliding down
along retainers on side plates, into fillpiece at bottom of
hood.
All of the hood components, including the filters, the gasketing
and the hardware for assembling are located above the top
filter racks within the filter section. The outdoor air sensor is in
the bag of parts located at the bottom of the return air section.
HOOD
FILTER COVER
COVER
GASKETED
FLANGE
OUTDOOR AIR
OPENING COVER
C
D
E
A
D
D
OUTDOOR AIR
SENSOR
GASKET
D
B
L. H. SIDE
PLATE
GASKETED
FLANGE
R. H.
SIDE
PLATE
FILTERS
FILTER SECTION
ACCESS PANEL
SIDE DUCT
APPLICATION SHOWN
FILLPIECE
FIG. 7 - ECONOMIZER RAIN HOOD ASSEMBLY (OPTION)
Unitary Products Group
7
530.18-N8Y
NOTE: Install filters so that “Air Flow” arrows point
toward the unit.
8. Install filter cover over the end of the hood with one
screw (center of hood), securing filters into position.
CAUTION: When proceeding with Steps 9 and 10, extreme care must be exercised while turning
both the set point and minimum position
adjusting screws to prevent twisting them
off.
9. The enthalpy set point for the dampers may now be
set by selecting the desired set point from graph in
Figure 8. For a single enthalpy economizer, carefully
turn the set point adjusting screw to the “A”, “B”, “C”
or “D” setting corresponding to the lettered curve.
For a dual enthalpy economizer, carefully turn the
set point adjusting screw fully clockwise past the “D”
setting.
10. To check that the damper blades move smoothly
without binding, carefully turn the minimum position
adjusting screw fully clockwise and then energize
and de-energize terminals “R” to “G”. With terminals
“R” to “G” energized, turn the minimum position
screw counterclockwise until the desired minimum
position has been attained.
11. Replace the filter section access panel.
FIG. 8 - ENTHALPY SET POINT ADJUSTMENT
TABLE 4 - PHYSICAL DATA
DCG
036
048
060
072
CENTRIFUGAL BLOWER (Dia. x Wd. in.) 12 x 10 12 x 10 12 x 10 12 x 11
1⁄
3⁄
FAN MOTOR HP (Direct-Drive)
1
1
2
4
FAN MOTOR HP (Belt-Drive)
1.5
1.5
1
1.5
ROWS DEEP
3
3
3
4
FINS PER INCH
13
13
13
13
FACE AREA (Sq. Ft.)
3.6
4.3
5.1
5.1
22
22
22
24
PROPELLER DIA. (in.)
1⁄
1⁄
1⁄
1⁄
FAN MOTOR HP
2
2
2
2
NOM. CFM TOTAL
4,500
4,200
4,500
4,500
ROWS DEEP
1
1
1
2
FINS PER INCH
16
19
22
16
FACE AREA (Sq. Ft.)
17.1
17.1
17.1
16.7
QUANTITY PER UNIT (14" x 20" x 1")
2
2
2
2
QUANTITY PER UNIT (14" X 25" X 1")
1
1
1
1
TOTAL FACE AREA (sq. ft.)
6.3
6.3
6.3
6.3
REFRIGERANT 22 (lbs./oz.)
6/0
6/6
7/4
10/3
MODELS
EVAP.
BLOWER
EVAP.
COIL
COND.
FAN
COND.
COIL
AIR
FILTERS
(SEE NOTE)
CHARGE
WEIGHTS (LBS)
3 Ton
615
4 Ton
655
Basic Unit
(Nom. Max.)
5 Ton
680
6 Ton
735
OPTIONS / ACCESSORIES
Economizer
50
Motorized Outdoor
48
Air Damper
Barometric Relief/Fixed
10
Outdoor Air Intake Damper
Roof Mounting Curb
92
Belt-Drive Blower
5
NOTE: Filter racks are adapted for 1" or 2" thick filters.
TABLE 5 - SUPPLY AIR PERFORMANCE - 3 Thru 6 Ton w/Direct-Drive Blower
GAS HEAT VALUES SHOWN @ 230/460/575 Volts - Side Duct Connections
MODEL
DCG
036
048
060
072
MOTOR
SPEED
HI
MED
LOW
HI
MED
LOW
HI
MED
LOW
HI
0.20
CFM
1684
1487
1996
1804
1681
2400
2290
2150
2461
Watts
800
710
960
838
760
1155
1105
1020
1480
0.30
CFM
1631
1464
1933
1765
1640
2338
2214
2100
2402
Watts
780
690
936
810
738
1125
1065
990
1440
0.40
CFM
1699
1582
1421
1868
1714
1604
2274
2145
2029
2361
Watts
825
750
670
910
785
715
1095
1030
950
1395
Available External Static Pressure - IWG*
0.50
0.60
0.70
CFM
1650
1524
1367
1795
1650
1541
2167
2071
1965
2260
Watts
785
720
650
880
765
695
1045
990
910
1350
CFM
1570
1410
1315
1722
1589
1490
2096
1990
1905
2178
Watts
755
690
620
845
735
670
1010
950
880
1305
CFM
1430
1324
1246
1635
1508
1416
1990
1911
1816
2101
Watts
725
650
605
820
705
645
980
920
838
1260
0.80
CFM
1360
1260
1185
1544
1407
1337
1887
1828
1724
2000
Watts
700
630
590
790
675
620
945
885
800
1205
0.90
CFM
1280
1185
1110
1419
1306
1230
1771
1724
1644
1914
Watts
680
610
570
765
645
595
905
835
770
1155
1.00
CFM
1180
1100
1020
1300
1195
1120
1629
1604
1531
1830
Watts
655
590
545
740
625
575
855
798
710
1110
NOTE: For 208 volts,multiply values by 0.95.
*Includes allowances for a wet evaporator coil, 1" filters and gas fired heat exchangers. Refer to Table 8 for static resistance values on applications other than side duct airflows.
8
Unitary Products Group
530.18-N8Y
TABLE 6 - SUPPLY AIR PERFORMANCE - 3 & 4 Ton w/Belt-Drive Blower
3 TON - SIDE DUCT CONNECTIONS @ 230/460/575 Volts
MODEL AIR FLOW
DCG
CFM
036
1700
1600
1500
1400
1300
1200
1100
1000
900
MODEL AIR FLOW
DCG
CFM
036
1700
1600
1500
1400
1300
1200
1100
1000
900
0.20
RPM Watts
835
705
811
655
782
610
-
0.30
RPM Watts
880
745
854
695
827
650
798
595
-
Available External Static Pressure - IWG*
0.40
0.50
0.60
RPM Watts RPM Watts RPM Watts
923
795
969
860
1013
970
898
740
942
790
986
840
871
685
917
730
960
775
844
640
889
680
932
720
816
590
862
635
907
675
834
585
881
630
809
550
855
590
782
510
829
545
797
500
0.70
RPM Watts
1029
900
1003
825
975
765
951
715
927
665
900
625
872
858
843
540
0.80
RPM Watts
1046
905
1018
790
995
750
970
705
942
665
919
625
890
580
0.90
RPM Watts
1055
875
1036
780
1011
735
987
690
963
655
936
615
1.00
RPM Watts
1066
850
1047
765
1028
720
1005
680
980
645
Available External Static Pressure - IWG*
1.10
1.20
1.30
RPM Watts RPM Watts RPM Watts
1075
800
1060
750
1084
775
1040
695
1068
715
1089
735
1020
660
1050
670
1053
680
1.40
RPM Watts
1090
690
1.50
RPM Watts
-
NOTE: FOR 208 VOLTS, MULTIPLY VALUES BY 0.95.
*INCLUDES ALLOWANCES FOR A WET EVAPORATOR COIL, 1" FILTERS, AND
GAS-FIRED HEAT EXCHANGERS. REFER TO TABLE 8 FOR RESISTANCE VALUES ON CONNECTIONS
OTHER THAN SIDE DUCT AIRFLOWS.
4 TON - SIDE DUCT CONNECTIONS @ 230/460/575 Volts
MODEL AIR FLOW
DCG
CFM
048
2000
1900
1800
1700
1600
1500
1400
1300
1200
MODEL AIR FLOW
DCG
CFM
048
2000
1900
1800
1700
1600
1500
1400
1300
1200
0.20
RPM Watts
843
860
817
775
790
700
-
0.30
RPM Watts
880
925
854
850
828
760
802
670
-
Available External Static Pressure - IWG*
0.40
0.50
0.60
RPM Watts RPM Watts RPM Watts
919
1005
956
1065
993
1145
893
920
930
995
970
1065
867
840
906
905
944
980
840
745
881
815
920
900
818
665
858
740
898
820
842
695
882
755
833
650
867
705
858
665
847
640
0.70
RPM Watts
1030
1195
1008
1125
985
1040
961
970
940
890
922
835
904
765
893
725
880
680
0.80
RPM Watts
1067
1235
1046
1170
1025
1100
1001
1030
980
950
962
895
942
820
932
785
916
730
0.90
RPM Watts
1103
1270
1085
1210
1064
1145
1040
1075
1020
1005
1003
945
982
880
970
835
953
780
1.00
RPM Watts
1102
1180
1081
1115
1060
1050
1044
995
1024
920
1010
870
992
815
Available External Static Pressure - IWG*
1.10
1.20
1.30
RPM Watts RPM Watts RPM Watts
1121
1140
1100
1085
1086
1035
1067
965
1107
1000
1053
920
1099
960
1034
855
1080
905
-
1.40
RPM Watts
-
1.50
RPM Watts
-
NOTE: FOR 208 VOLTS, MULTIPLY VALUES BY 0.95.
*INCLUDES ALLOWANCES FOR A WET EVAPORATOR COIL, 1" FILTERS, AND
GAS-FIRED HEAT EXCHANGERS. REFER TO TABLE 8 FOR RESISTANCE VALUES ON CONNECTIONS
OTHER THAN SIDE DUCT AIRFLOWS.
Unitary Products Group
9
530.18-N8Y
TABLE 7 - SUPPLY AIR PERFORMANCE - 5 & 6 Ton w/Belt-Drive Blower
5 TON - SIDE DUCT CONNECTIONS @ 230/460/575 Volts
MODEL AIR FLOW
DCG
CFM
060
2500
2400
2300
2200
2100
2000
1900
1800
1700
1600
1500
MODEL AIR FLOW
DCG
CFM
060
2500
2400
2300
2200
2100
2000
1900
1800
1700
1600
1500
0.20
RPM Watts
1059
1560
1032
1405
1005
1260
980
1160
930
1060
877
950
-
0.30
RPM Watts
1077
1590
1054
1470
1024
1275
1002
1170
957
1070
908
975
-
Available External Static Pressure - IWG*
0.40
0.50
0.60
RPM Watts RPM Watts RPM Watts
1095
1630
1114
1650
1134
1660
1074
1525
1094
1560
1116
1595
1049
1370
1069
1440
1090
1475
1022
1190
1044
1250
1066
1350
983
1080
1010
1100
1039
1160
941
1000
976
1020
1009
1050
894
885
940
940
980
980
855
815
903
860
950
905
884
815
925
850
864
770
908
805
882
740
0.70
RPM Watts
1158
1685
1140
1620
1116
1505
1090
1410
1064
1260
1040
1100
1014
1020
988
940
964
880
948
835
926
780
0.80
RPM Watts
1181
1720
1167
1640
1142
1535
1117
1440
1092
1340
1070
1225
1047
1095
1022
970
1001
910
987
870
965
830
0.90
RPM Watts
1193
1665
1170
1580
1148
1480
1121
1385
1100
1285
1079
1180
1058
1060
1035
960
1020
900
1004
860
1.00
RPM Watts
1202
1620
1180
1530
1155
1425
1133
1340
1110
1240
1090
1135
1071
1030
1056
965
1038
880
Available External Static Pressure - IWG*
1.10
1.20
1.30
RPM Watts RPM Watts RPM Watts
1190
1475
1169
1385
1205
1445
1143
1280
1178
1330
1222
1375
1122
1190
1158
1240
1196
1295
1103
1100
1134
1140
1164
1175
1088
1035
1118
1065
1145
1105
1070
925
1101
980
1130
1045
1.40
RPM Watts
1197
1205
1170
1130
1158
1075
1.50
RPM Watts
1198
1150
1184
1110
NOTE: FOR 208 VOLTS, MULTIPLY VALUES BY 0.95.
*INCLUDES ALLOWANCES FOR A WET EVAPORATOR COIL, 1" FILTERS, AND GAS-FIRED HEAT EXCHANGERS. REFER TO
TABLE 8 FOR RESISTANCE VALUES ON CONNECTIONS
OTHER THAN SIDE DUCT AIRFLOWS.
6 TON - SIDE DUCT CONNECTIONS @ 230/460/575 Volts
MODEL AIR FLOW
DCG
CFM
072
3200
3000
2800
2600
2400
2200
2000
1800
MODEL AIR FLOW
DCG
CFM
072
3200
3000
2800
2600
2400
2200
2000
1800
0.20
RPM Watts
1150
2325
1100
2010
1045
1700
985
1425
930
1240
-
0.30
RPM Watts
1182
2425
1129
2090
1074
1780
1015
1475
958
1300
905
1070
-
Available External Static Pressure - IWG*
0.40
0.50
0.60
RPM Watts RPM Watts RPM Watts
1212
2525
1157
2150
1185
2225
1215
2290
1102
1850
1131
1940
1160
2025
1045
1540
1075
1630
1103
1715
990
1350
1020
1400
1051
1430
933
1160
965
1210
997
1250
919
1025
950
1100
909
925
0.70
RPM Watts
1242
2360
1190
2075
1135
1760
1081
1490
1028
1285
982
1130
939
1005
0.80
RPM Watts
1217
2130
1163
1825
1111
1600
1060
1325
1014
1160
968
1030
0.90
RPM Watts
1245
2190
1193
1920
1142
1675
1090
1380
1045
1175
998
1050
1.00
RPM Watts
1222
1990
1173
1730
1124
1450
1077
1200
1028
1060
Available External Static Pressure - IWG*
1.10
1.20
1.30
RPM Watts RPM Watts RPM Watts
1250
2060
1205
1800
1234
1885
1155
1550
1186
1640
1217
1710
1109
1275
1140
1360
1170
1460
1058
1060
1087
1075
1118
1150
1.40
RPM Watts
1249
1775
1205
1545
1148
1250
1.50
RPM Watts
1235
1600
1176
1360
NOTE: FOR 208 VOLTS, MULTIPLY VALUES BY 0.95.
*INCLUDES ALLOWANCES FOR A WET EVAPORATOR COIL, 1" FILTERS, AND GAS-FIRED HEAT EXCHANGERS. REFER TO
TABLE 8 FOR RESISTANCE VALUES ON CONNECTIONS
OTHER THAN SIDE DUCT AIRFLOWS.
10
Unitary Products Group
530.18-N8Y
(Direct-Drive Units)
DUCT COVERS - Units are shipped with all air duct
openings covered.
For side duct applications;
1. Remove and discard the supply and return air duct
covers.
2. Connect ductwork to duct flanges on the rear of the
unit.
For bottom duct applications;
1. Remove the side supply air duct cover to gain
access to the bottom supply air knockout panel.
2. Remove and discard the bottom knockout panel.
3. Replace the side duct cover.
4. With filter section access panel removed from the
unit, remove and discard the bottom return air
knockout panel.
5. Replace the filter access panel.
CLEARANCES
Front
Back
Left Side (Filter Access)
Right Side (Cond. Coil)
Below Unit1
Above Unit2
All dimensions are in inches. They are subject to change without notice. Certified dimensions will be provided upon request.
32"
12" (Less Economizer)
36" (With Economizer)
24" (Less Economizer)
36" (With Economizer)
24"
20"
72" (For Condenser Air Discharge)
111⁄2
3
1
111⁄2
2
45⁄8
Units may be installed on combustible floors made from wood or class A, B or C
roof covering material (Applicable in the USA only).
Units must be installed oudoors. Overhanging structures or shrubs should not
obstruct the outdoor coil nor the fan outlet.
NOTE: A 1" clearance must be provided between any combustible material and the
supply air ductwork for a distance of 3 feet from the unit.
The products of combustion must not be allowed to accumulate within a confined
space and recirculate.
Locate unit so that the vent air outlet hood is at least:
• Three (3) feet above any forced air inlet located within 10 horizontal feet (excluding
those integral to the unit).
• Four (4) feet below, 4 horizontal feet from, or 1 foot above any door or gravity air inlet
into the building.
• Four (4) feet from electric meters, gas meters, regulators and relief equipment.
171⁄2
171⁄2
61⁄2
REAR VIEW
SIDE SUPPLY AND RETURN
UTILITIES ENTRY DATA
HOLE
KNOCKOUT
SIZE
(DIA.)
A
7/8" *
77⁄8
B
2" *
C
D
1-5/8"
1-1/2"
USED FOR
Control Wiring
(Side or Bottom)**
Power Wiring
(Side or Bottom)
Gas Piping (Front)
Gas Piping (Bottom)
*Knockouts in the bottom of the unit can be located by the slice
in the insulation.
**Do not remove the 2" knockout ring.
AIR FLOW LEGEND
RETURN AIR
SUPPLY AIR
OUTDOOR AIR
OUTDOOR AIR
(Economizer)
FIG. 9 - DIMENSIONS AND CLEARANCE (3, 4, 5 & 6 TON)
Unitary Products Group
11
530.18-N8Y
TABLE 8 - STATIC RESISTANCES
EXTERNAL STATIC PRESSURE DROP
RESISTANCE, IWG
CFM
1000 1200 1400 1600 1800 2000 2200
0.07
0.08
0.09
0.11
0.13
0.15
0.17
0.06
0.07
0.08
0.09
0.10
0.11
0.12
DESCRIPTION
Economizer/Motorized Damper1, 2
Bottom Duct Connections1
2400
0.20
0.14
2600
0.23
0.16
2800
0.26
0.19
3000
0.30
0.22
1
Deduct
2
these resistance values from the available external static pressure shown in the respective Blower Performance Table.
The pressure thru the economizer is greater for 100% outdoor air than for 100% return air. If the resistance of the return air duct system is less than 0.25 IWG, the unit will deliver less CFM
during full economizer operation.
TABLE 9 - MOTOR AND DRIVE DATA - Belt-Drive Blower
HP
RPM
FRAME
SIZE
SERVICE
FACTOR
780 - 1090
790 - 1120
850 - 1220
900 - 1250
1
1-1/2
1-1/2
1-1/2
1100
1725
1725
1725
48
56
56
56
1.15
1.15
1.15
MODEL
DCG 036
DCG 048
DCG 060
DCG 072
MOTOR*
BLOWER
RANGE
(RPM)
ADJUSTABLE
MOTOR PULLEY
PITCH
BORE
DIA.
(in.)
(in.)
2.4 - 3.4
5/8
2.4 - 3.4
7/8
2.4 - 3.4
7/8
2.8 - 3.8
7/8
FIXED
BLOWER PULLEY
PITCH
BORE
DIA.
(in.)
(in.)
3.5
1
5.7
1
5.2
1
5.2
1
BELT
PITCH
LENGTH
(in.)
33.3
37.3
37.3
37.3
DESIGNATION
A32
A36
A36
A36
*All motors have solid bases and are inherently protected. These motors can be selected to operate into their service factor because they are located in the moving air, upstream of any
heating device.
TABLE 10 - ELECTRICAL DATA (BASIC UNIT) w/ Direct-Drive Blower Motor
MODEL
DCG
036
048
060
072
POWER
SUPPLY
208/230-1-60
208/230-3-60
460-3-60
575-3-60
208/230-1-60
208/230-3-60
460-3-60
575-3-60
208/230-1-60
208/230-3-60
460-3-60
575-3-60
208/230-3-60
460-3-60
575-3-60
VOLTAGE
LIMITATIONS
MIN.
MAX.
RLA
LRA
COND.
FAN
MOTOR,
FLA
187
187
414
518
187
187
414
518
187
187
414
518
187
414
518
253
253
504
630
253
253
504
630
253
253
504
630
253
504
630
19.2
14.1
7.1
5.8
23.1
14.7
7.1
6.4
28.2
16.7
9.6
8.3
20.7
10.0
8.2
87
110
54
44
105
130
64
52
135
150
73
59
156
70
54
2.3
2.3
1.4
1.4
2.3
2.3
1.4
1.4
2.3
2.3
1.4
1.4
2.3
1.4
1.4
COMPRESSOR
(SEE NOTE 1)
SUPPLY
AIR
BLOWER
MOTOR,
FLA
4.4
4.4
2.0
2.0
5.0
5.0
2.2
2.2
6.6
6.6
3.3
3.3
6.8
3.6
3.6
MAX.
MAX.
MIN.
TOTAL
FUSE
HACR
WIRE
UNIT
SIZE,
BREAKER
SIZE,
AMPACITY,
(SEE NOTE 2)
SIZE,
AWG
AMPS
AMPS
AMPS (SEE NOTE 3)
30.7
45
45
8
24.3
35
35
10
12.5
15
15
14
10.9
15
14
36.2
50
50
8
25.7
40
40
10
12.5
15
15
14
11.6
15
14
6
44.2
70
70
45
45
10
29.8
25
10
16.7
25
15.1
20
12
35.0
50
50
8
17.5
25
25
10
15.3
20
12
NOTES:1. Utilization Range “A” in accordance with ARI Standard 110.
2. Dual element, time delay type.
3. Based on 60°C copper conductors.
TABLE 11 - ELECTRICAL DATA (BASIC UNIT) w/ Belt-Drive Blower Motor
MODEL
DCG
036
048
060
072
POWER
SUPPLY
208/230-1-60
208/230-3-60
460-3-60
575-3-60
208/230-1-60
208/230-3-60
460-3-60
575-3-60
208/230-1-60
208/230-3-60
460-3-60
575-3-60
208/230-3-60
460-3-60
575-3-60
VOLTAGE
LIMITATIONS
MIN.
MAX.
RLA
LRA
COND.
FAN
MOTOR,
FLA
187
187
414
518
187
187
414
518
187
187
414
518
187
414
518
253
253
504
630
253
253
504
630
253
253
504
630
253
504
630
19.2
14.1
7.1
5.8
23.1
14.7
7.1
6.4
28.2
16.7
9.6
8.3
20.7
10.0
8.2
87
110
54
44
105
130
64
52
135
150
73
59
156
70
54
2.3
2.3
1.4
1.4
2.3
2.3
1.4
1.4
2.3
2.3
1.4
1.4
2.3
1.4
1.4
COMPRESSOR
(SEE NOTE 1)
SUPPLY
AIR
BLOWER
MOTOR,
FLA
5.3
5.3
3.1
3.1
8.6
5.2
2.6
2.0
8.6
6.0
3.0
2.4
7.3
3.7
2.8
TOTAL
UNIT
AMPACITY,
AMPS
31.6
25.2
13.4
11.8
39.5
25.9
12.9
11.4
46.2
29.2
16.4
14.2
35.5
17.6
14.5
MAX.
FUSE
SIZE,
(SEE NOTE 2)
AMPS
45
35
20
15
50
40
15
15
70
45
25
20
50
25
20
MAX.
HACR
BREAKER
SIZE,
AMPS
45
35
20
50
40
15
70
45
25
50
25
-
MIN.
WIRE
SIZE,
AWG
(SEE NOTE 3)
8
10
12
14
8
10
14
14
8
10
10
12
8
10
12
NOTES: 1. Utilization Range “A” in accordance with ARI Standard 110.
2. Dual element, time delay type.
3. Based on 60°C copper conductors.
12
Unitary Products Group
530.18-N8Y
OPERATION
COOLING SYSTEM
The cooling section is a complete factory package utilizing an
air-cooled condenser. The system is factory-charged with
Refrigerant-22.
The compressor is hermetically sealed and internally sprung.
The compressors have inherent (internal) protection. If there is
an abnormal temperature rise in the compressor, the protector
will open to shut down the compressor.
PRELIMINARY OPERATION COOLING
After the installation has been completed, energize the
crankcase heater for at least 4 hours before operating the unit.
After this initial warm-up, the compressor should be given three
false starts (energized just long enough to make a few
revolutions) with a 5 minute delay between each start before
being put into full time service.
NOTE: Prior to each cooling season, the crankcase heater
must be energized at least 10 hours before the system
is put into operation.
COOLING SEQUENCE OF OPERATION
Single-Stage Cooling: When the thermostat calls for “cooling”,
“R” is closed to “G” and “Y1" (wiring schematic) which
completes the low voltage control circuit, immediately
energizing the compressor, condenser fan motor and blower
motor simultaneously.
Two-Stage Cooling: A two-stage cooling thermostat may be
used if the unit has an economizer. First-stage cooling is
provided by the economizer - if the outdoor air enthalpy is
acceptable, and second-stage cooling is provided by the
compressor. Jumper wire J1 must be removed. Refer to the
unit wiring diagram.
After the thermostat is satisfied and opens, all components will
stop simultaneously.
CONTINUOUS BLOWER - Continuous blower operation is
possible by closing the R to G circuit on the thermostat.
SAFETY CONTROLS (Cooling)
The refrigerant system is equipped with the following safety
controls:
1. A Suction Line Freezestat to protect aginst low evaporator
temperatures due to a low air flow or a low return air
temperature.
2. A High Pressure Cutout Switch to protect against excessive
discharge pressures due to a blocked condenser coil or a
condenser motor failure.
3. A Low Pressure Switch to protect against loss of refrigerant
charge.
If either one of the above safety controls opens, the refrigerant
system will bo locked out. The lock out of the system can be
reset by opening the 24V circuit either at the room thermostat
or at the unit disconnect.
normally closed blower interlock relay contact “K3-1" provides
24 volt power to the blower relay ”BR". The “BR” power contacts
close and the blower motor operates.
INTERMITTENT BLOWER: With the room thermostat system
switch set to the “AUTO” or “HEAT” position and the fan switch
set to “AUTO”, the supply air blower will operate after the room
thermostat calls for heat and the air in the gas heat
compartment has achieved a pre-set temeprature.
When “TH1" on the thermostat closes, the draft motor relay
”DMR" is energized. The “DMR” power contacts close which
energizes the line voltage draft motor. As the speed of the draft
motor reaches approximately 2500 RPM, the centrifugal switch
contact “CS” located on the end of the draft motor shaft closes
to power the ignition control “IC”.
After 15 seconds, the "IC" will start the ignitor sparking and will
open the redundant valve locted inside the main gas valve “GV”
to allow a flow of gas to only the carryover tube. See Figure 10.
Only after the pilot flame has been ignited and the presence of
pilot flame detected at the “IC” by a signal sent back through
the flame sensor is sparking terminated and the main gas valve
opened.
Gas flows into each of the main burners and is ignited from the
carryover tube flame.
The "IC" will try for 85 seconds to ignite the pilot carryover tube.
If the "IC" fails to detect a pilot flame during the 85 seconds, it
will close the redundant valve. After a 5 minute purge period,
the "IC" will again try to light the pilot carryover tube. This will
continue continuously until the "IC" detects a pilot flame.
If, after detecting a pilot flame and opening the main gas valve,
the "IC" looses pilot flame indication, it will close both the main
and redundant gas valves. The "IC" will start the above
sequence over until a pilot flame is detected and it will open the
main gas valve again.
The "IC" will only allow 16 pilot flameouts and a single rollout
switch opening per thermostat cycle. After 16 pilot flameouts or
a single rollout switch opening, the "IC" closes both the main
and redundant gas valves. The "IC" requires resetting the
thermostat or removal of it’s power lead coming from the draft
motor to reset the "IC" and return it to the above sequence of
operation.
At the same time power was supplied to the “DMR”, a parallel
circuit activates the time delay relay (TDR). The “TDR” closes
in approximetly 35 seconds and starts the circulating air blower
by energizing the blower interlock relay “K3", thus closing the
”K3-2" contact and energizing the blower relay “BR”.
When the heating cycle is complete, “TH-1" opens
de-energizing the “IC”, thus closing the redundant and main
gas valves. The blower motor and the draft motor continue to
run for a short period after the furnace is shut down until the
“TDR” opens (in approximately 30 seconds) de-energizing the
“K3", ”BR" and "DMR" relays.
REDUNDANT
VALVE
MAIN VALVE
GAS MAIN
HEATING SEQUENCE OF OPERATION
The following sequence describes the operation of the gas heat
section.
CONTINUOUS BLOWER: With the room thermostat switch set
to “ON”, the supply air blower will operate continuously. The
Unitary Products Group
GAS
VALVE
TO PILOT BURNER
TO MAIN
BURNER
FIG. 10 - GAS VALVE PIPING
13
530.18-N8Y
SAFETY CONTROLS (Heating)
The control circuit includes the following safety controls:
1. Limit Control (LS). This control is located inside the heat
exchanger compartment and is set to open at the
temperature indicated in Table 12. It resets automatically.
The limit switch, operates when a high temperature
condition, caused by inadequate supply air flow occurs,
thus shutting down the ignition control and closing the main
gas valve.
TABLE 12 - LIMIT CONTROL SETTING
Units
(Tons)
3
4
3
4
5
5
6
6
Capacity, MBH
Input
Output
50
40
75
60
100
79
125
99
100
79
125
99
100
79
125
99
Limit Control
Opens, °F
165
165
165
165
165
165
165
165
2. Centrifugal Switch (CS-36). If the draft motor should fail,
the centrifugal switch attached to the shaft of the motor
prevents the ignition control and gas valve from being
energized.
3. Redundant Gas Valve. This valve is an integral part of the
main gas valve and is located up stream of the main gas
valve. Should the main gas valve fail in the open position
the redundant valve serves as a back up and shuts off the
flow of gas.
4. Flame Sensor Rod. This sensor rod is located on the far
side of the carryover tube. If the ignition control does not
receive a signal from the flame sensor indicating that the
pilot flame has ignited properly, the main gas valve will not
open. If the flame sensor fails to detect the pilot flame during
operation of the main burners, a signal is sent to the ignition
control to close the main gas valve.
5. Rollout Switch. This switch is located in the burner
vestibule. In the event of a sustained main burner flame
rollout, it shuts off the ignition control and closes the main
gas valve.
HEAT ANTICIPATOR SETPOINTS
The anticipator must be set correctly. Too high of a setting will
result in longer heat cycles and a greater temperature swing in
the conditioned space.
Reducing the value below the correct setpoint will give shorter
“ON” cycles and may result in the lowering of the temperature
within the conditioned space.
Gas Valve
Honeywell VR8204M
White-Rodgers 36E36
Anticipator Setpoint
0.60 amp
0.54 amp
PRE-START CHECK LIST
Complete the following checks before starting the unit.
1. Check the type of gas being supplied. Be sure that it is the
same as listed on the unit nameplate.
2. Make sure that the vent and combustion air hoods have
been properly installed.
START-UP
OPERATING INSTRUCTIONS
MANIFOLD GAS PRESSURE ADJUSTMENT
CAUTION: This furnace is equipped with an intermittent pilot
and automatic re-ignition system. DO NOT attempt
to manually light the pilot.
Small adjustments to the high-fire gas flow may be made by
turning the pressure regulator adjusting screw on the automatic
gas valve. Refer to Figure 11.
TO LIGHT PILOT AND MAIN BURNERS:
1. Turn “off” electric power to unit.
2. Turn room thermostat to lowest setting.
“ON”-"OFF"
CONTROL
HIGH FIRE ADJ.
(UNDER SCREW)
PILOT ADJ.
(UNDER
SCREW)
3. Turn gas valve knob to “on” position.
4. Turn “on” electric power to unit.
Honeywell
VR8204M
5. Set room thermostat to desired temperature.
(If therm ost at “s et” temperature is above room
temperature, pilot burner ignition will occur and, after an
interval to prove pilot flame, main burners will ignite).
TO SHUT DOWN:
1. Turn “off” electric power to unit.
2. Depress knob of gas valve while turning to “off” position.
POST-START CHECK LIST (GAS)
“ON”-"OFF" CONTROL
PILOT ADJ.
(UNDER
SCREW)
White-Rodgers
36E36
PRESSURE REGULATOR
MANIFOLD ADJUST. SCREW
1/2-14 NPT (OUTLET)
After the entire control circuit has been energized and the
heating section is operating, make the following checks:
FIG. 11 - GAS VALVES
1. Check for gas leaks in the unit piping as well as the supply piping.
Adjust as follows:
2. Check for correct manifold gas pressures. See “Checking
Gas Input”.
1. Remove the cap on the regulator. (High Fire adjusting
screw on valve).
3. Check the supply gas pressure. It must be within the limits
shown on rating nameplate. Supply pressure should be
checked with all gas appliances in the building at full fire.
At no time should the standby gas line pressure exceed 13",
nor the operating pressure drop below 4.5" for natural gas
units. If gas pressure is outside these limits, contact the
local gas utility for corrective action.
2. To decrease the gas pressure, turn the adjusting screw
counterclockwise.
14
3. To increase the gas pressure, turn the adjusting screwclockwise.
NOTE: Check the rating/orifice data label on the blower access
panel for the proper manifold pressure of the furnace.
Unitary Products Group
530.18-N8Y
PILOT CHECKOUT
The pilot flame should envelope 3/8 inches of the end of the
flame sensor. Refer to Figure 12. To adjust pilot flame, (1)
remove pilot adjustment cover screw, (2) adjust the screw for
the proper pilot flame, (3) be sure to replace cover screw after
adjustment to prevent possible gas leakage.
TABLE 13 - BELT-DRIVE SUPPLY AIR
MOTOR PULLEY ADJUSTMENT
TURNS
OPEN*
5
4
3
2
1
0
3 TON
780
842
904
966
1028
1090
BLOWER DRIVE RANGE (RPM)
4 TON
5 TON
790
850
856
924
922
998
988
1072
1054
1246
1120
1220
6 TON
900
970
1040
1110
1180
1250
*Pulley can be adjusted in half-turn increments.
OPTIONAL BELT-DRIVE BLOWER
FIG. 12 - PROPER FLAME ADJUSTMENT
Put the system into operation and observe through complete
cycle to be sure all controls function properly.
All units with belt-drive blowers have single-speed motors. The
variable pitch pulley on the blower motor can be adjusted to
obtain the desired supply air CFM. Refer to Table 9 for blower
motor and drive data. The tension on the belts should be
adjusted as shown in Figure 14.
BURNER INSTRUCTIONS
To check or change burners, pilot or orifices, CLOSE MAIN MANUAL
SHUT-OFF VALVE AND SHUT OFF ALL POWER TO THE UNIT.
1. Remove the two screws holding either end of the manifold
to the burner supports.
2. Open the union fitting in the gas supply line just upstream of the unit
gas valve and downstream from the main manual shut-off valve.
3. Remove the gas piping patch plate.
4. Disconnect wiring to the gas valve and spark ignitor.
Remove the manifold-burner gas valve assembly by lifting
up and pulling back.
Burners are now accessible for service.
Reverse the above procedure to replace the assembly. Make sure
that burners are level and seat at the rear of the heat exchanger.
BURNER AIR SHUTTER ADJUSTMENT
Adjust burner shutters so that a distinct, sharp, blue flame is
obtained. Refer to Figure 13.
FIG. 14 - BELT ADJUSTMENT
Start the supply air blower motor. Adjust the resistances in both
the supply and the return air duct systems to balance the air
distribution throughout the conditioned space. The job
specifications may require that this balancing be done by
someone other than the equipment installer.
FIG. 13 - TYPICAL FLAME APPEARANCE
SUPPLY AIR BLOWER AND TEMPERATURE RISE
ADJUSTMENTS
The speed of the supply air blower will depend on the required
CFM, the unit accessories and the static resistances of both
the supply and the return air duct systems. With this
information, the speed for the supply air blower can be
determined from the blower performance and accessory static
resistance data in Tables 5 through 8.
To check the supply air CFM after the initial balancing has been
completed:
1. Drill two 5/16 inch holes in the side panels as shown in Figure 15,
if they are not already supplied at this location.
2. Insert at least 8" of 1/4 inch tubing into each of these holes
for sufficient penetration into the air flow on both sides of
the evaporator coil.
Knowing the required blower RPM and the blower motor HP,
the speed setting for the supply air motor can be determined.
NOTE: The tubes must be inserted and held in a position
perpendicular to the air flow so that velocity pressure will not affect the static pressure readings.
The setting (turns open) for the optional belt-drive supply air
motor pulley can be determined from Table 13.
3. Using an inclined manometer, determine the pressure drop
across a dry evaporator coil. Since the moisture on an
Unitary Products Group
15
530.18-N8Y
evaporator coil may vary greatly, measuring the pressure
drop across a wet coil under field conditions would be
inaccurate. To assure a dry coil, the compressors should
be de-energized while the test is being run.
4. Knowing the pressure drop across a dry coil, the actual CFM
through the unit can be determined from the curve in Figure 16.
NATURAL GAS
1. Turn off all other gas appliances connected to the gas meter.
2. With the furnace turned on, measure the time needed for one
revolution of the hand on the smallest dial on the meter. A
typical gas meter usually has a 1/2 or a 1 cubic foot test dial.
The temperature rise (or temperature difference between the return
air and the heated air from the furnace) must lie within the range
shown on the UL or CGA rating plate and the data in Table 2.
If the CFM is above or below the specified value, the supply air
motor speed may have to be changed by moving the motor
speed tap to another terminal.
3. Using the number of seconds for each revolution and the
size of the test dial increment, find the cubic feet of gas
consumed per hour from Table 14.
Btuh Input x 0.8
1.08 x oF Temp. Rise
WARNING: Failure to properly adjust the total system air quantity can result in poor system performance.
NOTE To find the Btu input, multiply the number of cubic feet of
gas consumed per hour by the Btu content of the gas in
your particular locality (contact your gas company for this
information - it varies widely from city to city.)
CFM =
After readings have been obtained, remove the tubes and seal up
the drilled holes in the side panels. 5/16" dot plugs (P/N 029-13880)
are available through normal parts ordering procedures.
161⁄
DAMPER
ASSEMBLY
2“
171⁄
8“
5⁄ “
16
HOLES
21"
INDOOR
COIL
DUCT FLANGES
(Back of Unit)
L.H. END VIEW
(Filter Access End)
FRONT OF UNIT
FIG. 15 - HOLE LOCATIONS
(PRESS. DROP READINGS)
0.6
If the actual input is not within 5% of the furnace rating (with
allowance being made for the permissible range of the regulator
setting) replace the orifice spuds with spuds of the proper size.
TABLE 14 - GAS RATE - CUBIC FEET PER HOUR
Seconds
for One
Rev.
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
60
FILTERS
DCG060,072
DCG048
0.5
PRESSURE DROP (IWG)
CHECKING GAS INPUT
DCG036
Size of Test Dial
1/2 cu. ft.
1 cu. ft.
180
150
129
113
100
90
82
75
69
64
60
56
53
50
47
45
43
41
39
37
36
35
34
32
31
30
360
300
257
225
200
180
164
150
138
129
120
113
106
100
95
90
86
82
78
75
72
69
67
64
62
60
Example: By actual measurement, it takes 38 seconds for the hand on the 1-cubic
foot dial to make a revolution with just a 100,000 Btuh furnace running. Using this
information, locate 38 seconds in the first column in the table above. Read across
to the column headed “1 Cubic Foot”, where you will see that 95 cubic feet of gas
per hour are consumed by the furnace at that rate. Multiply 95 x 1050 (the Btu
rating of the gas obtained from the local gas company). The result is 99,750 Btuh,
which is close to the 100,000 Btuh rating of the furnace.
0.4
0.3
0.2
0.1
0.0
8
11
17
14
20
NOMINAL CFM (HUNDREDS)
23
26
FIG. 16 PRESSURE DROP vs SUPPLY AIR CFM
SECURE OWNER’S APPROVAL: When the system is functioning properly, secure the owner’s approval. Show him
the location of all disconnect switches and the thermostat. Teach him how to start and stop the unit and how to adjust temperature settings within the limitations of the system.
16
Unitary Products Group
530.18-N8Y
MAINTENANCE
NORMAL MAINTENANCE
CAUTION: Prior to any of the following maintenance procedures, shut off all power to the unit to prevent
personal injury.
Periodic maintenance normally consists of changing or
cleaning filters and (under some conditions) cleaning the main
burners.
FILTERS - Inspect once a month. Replace disposable or clean
permanent type as necessary. DO NOT replace permanent
type with disposable.
MOTORS - Indoor fan and outdoor fan motors are permanently
lubricated and require no maintenance. Ventor motor is factory
lubricated for an estimated 10 year life.
OUTDOOR COIL - Dirt should not be allowed to accumulate
on the outdoor coil surface or other parts in the air circuit.
Cleaning should be as often as necessary to keep coil clean.
Use a brush, vacuum cleaner attachment, or other suitable
means. If water is used to clean coil, be sure power to the unit
is shut off prior to cleaning.
NOTE: Exercise care when cleaning the coil so that the coil
fins are not damaged.
Do not permit the outdoor air discharge to be obstructed by overhanging structures of shrubs.
BURNER & PILOT - Periodically (at least annually at the beginning
of each heating season) make a visual check of the pilot and main
burner flame. If necessary, adjust main burner primary air shutters
so that no yellow flame is observed as explained under “BURNER
AIR SHUTTER ADJUSTMENT”. If it is not possible to adjust for
the proper flame, the burners may need cleaning.
TO CLEAN BURNERS - Remove them from the furnace as
explained in “Burner Instructions”. Clean burners with hot water
applied along top of the burner.
COMBUSTION AIR DISCHARGE - Visually inspect discharge
outlet periodically to make sure that the buildup of soot and dirt
is not excessive. If necessary, clean to maintain adequate
combustion air discharge.
The manufacture recommends that the furnace system be
inspected once a year by a qualified service person.
Unitary Products Group
CLEANING FLUE PASSAGES AND HEATING
ELEMENTS
With proper combustion adjustment the heating element of a
gas fired furnace will seldom need cleaning. If the element
should become sooted, it can be cleaned as follows:
1. Remove the burner assembly as outlined in “BURNER
INSTRUCTIONS”.
2. Remove the roof over the gas heat section.
3. At the top front of the heat section, remove the screws
holding the top of the flue collector box. Carefully remove
the top of the flue collector box without ripping the adjacent
insulation.
4. Lift out the flue diverter baffle.
5. On the inside of the flue collector box, remove the screws
holding the flue baffle. Remove the flue baffle.
6. Using a wire brush on a flexible wand, brush out the inside
of each heat exchanger from the burner inlet and flue outlet
ends.
7. Brush out the inside of the flue collector box and the flue
baffles.
8. Run the wire brush down the vent tube from the flue
collector end.
9. If soot build-up is particularly bad, remove the vent motor
and clean the wheel and housing. Run the wire brush down
the flue extentions at the outlet of the vent housing.
10. After brushing is complete, blow all brushed areas with air
or nitrogen. Vacuum as needed.
11. Replace parts in the order they were removed in Steps
1 to 5.
12. When replacing the top of the flue collector box, be careful
so as not to tear the adjoining insulation.
13. Assure that all seams on the vent side of the combustion
system are air tight. Apply a high temperature (+500°F)
sealing compound where needed.
17
530.18-N8Y
TROUBLESHOOTING
WARNING: Troubleshooting of components necessarily requires opening the electrical control box with the
power connected to the unit. Use extreme care
when working with live circuits! Check the unit
nameplate for the correct line voltage and set the
volt meter to the correct range before making any
connections with line terminals.
CAUTION: The wire number or color and terminal designations referred to may vary. Check the wiring label
inside the control box access panel for the correct
wiring.
1. Draft motor operates and furnace lights but supply air
blower does not start after a short time delay with room
thermostat fan switch set to “AUTO”.
a. Set fan switch to “ON”. If blower motor runs, go to Step
f. If it does not, check to see if line voltage is being
supplied to the contacts of the blower relay, “BR”, and
if the blower relay is pulled in. Check for loose wiring.
b. If “BR” is pulled in, touch the supply air blower motor
housing. If it is hot the motor may be off on inherent
protection. Disconnect power to the unit and check the
blower motor capacitor. If it is defective, replace it with
one of equal capacitance and voltage.
c. If “BR” is pulled in and the blower motor still does not
run, replace the blower motor.
d. If “BR” is not pulled in check for 24 volts at the “BR” coil.
If 24 volts is present, replace the “BR” relay.
e. If 24 volts is not present at the “BR” coil, check for loose
24 volt wiring back to the relay board. Check control
wiring to the room thermostat. If all is fine, replace the
relay board.
f. If the blower motor runs with the fan switch in the “ON”
position but does not run soon after the furnace has
ignited with the fan switch in the “AUTO” position, check
for loose 24 volt wiring between the relay board in the
main control box, the Mate-N-Lok connector in the
partition between the evaporator and gas heat sections
and the time delay relay (TDR).
g. If all control wiring is fine, check for 24 volts at the relay
board. If 24 volts is present, replace the relay board. If
24 volts is not present, replace the “TDR”.
NOTE: The furnace may shut itself down on a high temperature condition during the procedure but this will not
effect the test if it is done within 5 minutes of furnace
shut-down.
2. The supply air blower operates but the draft motor does not
when the room thermostat is set to call for heat and the fan
switch in the “ON” position.
a. The draft motor has inherent protection. If the motor shell
is hot to the touch, wait for the internal overload to reset.
b. If the motor shell is cold with the room thermostat calling
for heat, check for line voltage at the motor’s Mate-NLok connector attached to the evaporator partition. If
line voltage is present, replace the draft motor.
c. If line voltage is not present, check for line voltage at
the draft motor relay (DMR) contacts in the main control
box and check to see if the “DMR” is pulled in.
18
d. If the “DMR” relay is pulled in, check for a loose line
voltage connection.
e. If the “DMR” relay is not pulled in, check for 24 volts at
the “DMR” coil. If 24 volts is present, replace the “DMR”
relay. If 24 volts is not present, check for a loose 24 volt
connection back to the relay board and check the
connections from the room thermostat to the relay
board. If all connections are correct, replace the relay
board.
3. The draft motor runs but the furnace does not light and the
sparker does not spark.
a. Check all 24 volt connections from the relay board to
and in the gas heat section. Check low voltage connections to the “TDR” located in the control box.
b. If the furnace is hot, it may be out on an over temperature condition, wait for limit reset.
c. If the furnace is cold, check for 24 volts at wire 62
attached to the “TDR” located in the control box. If 24
volts is not found, replace the fan-limit.
d. If 24 volts is found at wire 62, remove the wires attached
to the “TDR” and with a VOM, check for continuity
across “TDR”. If none is found, the “TDR” is open and
must be replaced. If there is continuity, re-attach the
wires.
With the draft motor running, check for 24 volts at
terminal 24V on the ignitor control (IC) where the red
lead from the draft motor attaches. If 24 volts is not
present, the centrifugal switch (CS) has not closed or
has gone bad. Check the line voltage to the unit, if it is
correct replace the draft motor. If line voltage is low call
the power company.
e. If 24 volts is present at the ignitor control, check all
control wiring at the ignitor control and the high tension
wire to the ignitor. Check that the greeen ground wires
from the ignitor control, the gas valve and pilot burner
are all intact and making good electrical connection.
Check to make sure that the ceramic insulator on the
pilot ignitor or sensor is not broken or cracked, if all are
intact replace the ignition control “IC”.
4. The draft motor runs and the sparker sparks at the pilot
burner but the pilot does not ignite and a gas odor is not
detected at the draft motor outlet.
a. Check to make sure gas is being supplied to the unit.
Make sure that the gas pressure to the unit is within the
proper limits as described in the “POST START CHECK
LIST” and that the pilot adjust screw is allowing some
flow of gas as described in “PILOT CHECKOUT”.
b. Check all wiring between the ignitor control and the gas valve.
Check to make sure the ground connections are intact.
c. If the wiring is intact, check for 24 volts across terminals
“PV” and “COMMON” on the ignitor control. If 24 volts
is not present, replace the ignitor control.
d. If 24 volts is present, remove the pilot burner and
remove the pilot orifice from the pilot burner. The orifice
is removed in the direction opposite the flow of gas.
Inspect the orifice for obstruction. If it is clear, replace
the main gas valve.
Unitary Products Group
530.18-N8Y
5. The sparker sparks at the pilot burner but the pilot does not
ignite and a gas odor is detected at the draft motor outlet.
7. The pilot burner lights and the spark stops but the main
burners do not light.
a. Adjust the pilot adjust screw on the gas valve as described in “PILOT CHECKOUT”.
a. Check electrical connections between the ignitor control and the gas valve. If intact, check for 24 volts across
terminals “MV” and “COMMON” terminals. If not voltage
detected, replace ignitor control If voltage is present,
replace gas valve.
b. Check the supply pressure as described in “POST
START CHECK LIST”. Make adjustments as necessary.
c. Check the pilot orifice for obstruction as described in
Item 4. Clean as needed but the problem should not be
the gas valve.
6. The pilot burner ignites but the sparker continues to spark
and the main burners do not ignite.
a. Make the same checks and adjustment as described in Item 5.
8. Furnace lights with roll out or one burner has delayed ignition.
a. Make sure that the pilot burner is aligned properly with
the carryover as described in “PILOT CHECKOUT”.
b. Make sure that the carryovers on adjoining burners are
screwed fast and are level with respect to one another.
9. Main burners light but exhibit erratic flame characteristics.
b. Make sure that the pilot burner is not bent or damaged.
c. Make sure that the ground connections at the pilot
burner, gas valve and ignitor control are intact. Check
the high tension wire for good electrical connection. If
all are intact, replace the ignitor module.
Unitary Products Group
a. Adjust air shutters as described in “BURNER AIR
SHUTTER ADJUSTMENT”.
b. Check the main burner orifices for obstruction and
alignment. Removal procedure is described in
“BURNER INSTRUCTIONS”. Clean or replace burner
orifices and burners as needed.
19
Unitary Products Group
P.O. Box 1592, York, Pennsylvania USA 17405-1592
Subject to change without notice. Printed in U.S.A.
Copyright  by York International Corporation 1995. All Rights Reserved.
530.18-N8Y
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