63-8592 - Application Manual for T6984 &

Application Manual For T6984 & T7984 Series Thermostats
Content:
1. Terms and Definition ..................................................................... 3
2. Control Sequences........................................................................ 5
3. Screw Terminals Arrangement......................................................11
4. Thermostat Dip Switch Definition ..................................................13
5. Application Notes ..........................................................................15
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•
•
•
•
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PI control vs. On/Off control.................................................................................16
Modulating floating control vs. Analog 2 to 10 Vdc control ..................................17
Setpoint dial definition & setpoint limitation..........................................................18
4 to 20 ma. output models ...................................................................................21
Installation of auxiliary screw terminals and general wiring information...............22
On/off output 2: cycle per hour dip switch setting ................................................25
6. Application Drawings For Valves ..................................................27
•
2 way and 3 way valves for heating and/or cooling
7. Application Drawings For Zone Dampers .....................................41
•
•
•
•
Zone dampers
By-pass
Pressure dependent VAV
Mechanically compensated VAV
8. Checkout & Start Up Procedures ..................................................51
T6984 Product Data Manual
T7984 Product Data Manual
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2
1. Terms And Definitions
Changeover input
Heat/Cool
changeover of
ouput 1
Models T6984E, T7984A & C all have the possibility of changeover for output 1. Automatic
changeover is used on systems were a valve or a VAV unit may have cold and hot water or air in
the same system depending on the season. Basically output 1 is primarily cooling (Direct Acting)
when the changeover input is not activated. Activating the changeover input reverses the
function of output 1 to heating mode ( Reverse Acting ) so that the thermostat can use the end
device as a heating device instead of a cooling device.
For the T6984E only a dry contact can be used for changeover.
For the T7984 series a dry contact or 1 sensor per thermostat can be used for changeover.
( See the Multiple & single transformer wiring application )
Mode input
Models T6984D, T7984B have a mode input. These thermostat are designer to operate and
function in 2 distinct mode of operation depending on the application requirements.
This input is not a changeover input for output 1. Installing a jumper on the mode input will
reverse modulating output 1 to operate as a heating only output & the on/off output 2 as a
cooling only output. ( see the control sequence section )
Dip switch
Some thermostat have internal dip switch inside for adjustment of certain parameters.
Those dip switch are accessible by removing the front cover. Be sure to familiarize yourself with
what functions each switch represent ( See thermostat dip switch definition section )
Dip switch setting
When you are familiar with the switch, be sure to select a setting that matches the application
and the selected end devices.
End device
Any peripheral component which is being controlled by the thermostat: valves, damper
actuators, relays, ect........
LED
All thermostat have internal service LED & a system status Led on the cover. The internal
service LED are colored lights that can be viewed from the side of the thermostat they are
energized and the system status LED is the one mounted on the cover. ( See the checkout &
start up procedures section )
Modulating analog
2 to 10 Vdc output
T7984 series
A type of modulating signal that uses a variable DC voltage signal. This type of output on the
T7984 series uses a half wave rectifier bridge. If the same transformer is to be used for the
thermostat and the end device, be sure to select end devices which also use a half wave rectifier
bridge.
Modulating tristate floating
output
T6984 series
A type of modulating signal that uses a set of 2 contacts, one to open the end device, the other
to close the end device. This type of output uses tri-state or floating type actuators. The actuator
will open and close to multiple position according to demand. When the demand and the
temperature is satisfied, the thermostat will stop moving the actuator and will leave to its last
position until the demand changes again.
Motor timing
definition T6984
and modulating
floating output
only
It is important when using T6984 and modulating floating actuator that motor timing dip switch
setting matches the actuator being used. The motor maximum timing is the maximum running
time that the actuator may take to complete full stroke or maximum rotation. For optimum
control, select a dip switch timing setting which is equal or slightly shorter than the actual
maximum running time.
( 20, 30, 60, 120, 150, 240, or 420 seconds )
Night setback,
day-night mode
or NSB
An energy saving mode by which the actual setpoints are modified to different value than the
ones adjusted on the dial. The cooling setpoint will go up and the heating setpoint will go down.
This mode is energized with a dry contact from a remote time clock.
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Power supply
All electronic thermostat need power supply in order to work. 19/30 Vac, 50/60 Hz, 2 VA
Be sure to respect the polarity between each thermostat when using a common transformer.
( 24 Vac & 0 Vac ) The 2 VA rating does not include the power requirement of peripheral end
devices being controlled by the thermostat.
Power up
sequence
Every time power is removed and reapplied to a thermostat, it will go through a power up
sequence. This sequence resets all the function of the thermostat to the desired settings. ( See
the checkout & start up procedures section )
PTC fuse
All on/off output and the open/close output ( output 1 on T6984 ) use PTC fuse for protection.
These fuse are self resetting and are rated at 1.1A maximum inrush, 0.5A maximum running. If
a short occur, remove power to the thermostat for 30 seconds to reset the fuses. Remedy
problem before putting power back to the thermostat.
On/off output
An output which is normally used to control terminal reheat in a zone system. Example: electric
base board relay, electric duct heater relay, perimeter on/off 24 Vac valve, ect......
Remote sensor
All thermostat have their internal sensing device ( Thermistor ) mounted internally in the
thermostat. On the T6984D & E & T7984A, B & C models, it is possible to install a remote room
or remote duct return sensor at a different location than the thermostat. The remote sensor are
not to be used for supply control applications.
Output 1
Main output of the thermostat. On the T6984 series that output is a modulating floating type. On
the T7984 series that output is analog 2 to 10 Vdc.
Triac output
All reheat output and the open/close output ( output 1 on T6984 ) use electronic triac. A triac is
the equivalent of an electronic dry contact, although it has no coil or mechanical moving parts.
These triac outputs are protected with self resetting fuses and are rated at 1.1A maximum
inrush, 0.5A maximum running. When they are energized by the thermostat, their switching
action is as follow:
Output 2
On/off
Motor open
Output 1
Motor close
24 Vac
Power supply
( 0 Vac )
24 Vac valve or VAV
floating actuator
Open
Close
Common
R
24 Vac on/off
relay or valve
24 Vac transformer
1. The leg of the transformer being switched by the triacs is the 0 Vac leg.
2. On the T6984, the common of the floating actuator being used is wired to the 24 Vac leg of
the thermostat
3. On Reheat outputs, the other side of the relay or end device being used is wired to the 24
Vac leg of the thermostat
Zero energy band,
deadband
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On thermostats which have output 1 cooling and output 2 heating ( T6984D, T7984B&C models
only ), the setpoint dial definition needs to be adjusted. ( See setpoint dial definition & setpoint
limitation application note )
These thermostats have 2 distinct setpoints, one for heating the other for cooling ( See the
control curves section ). When the room temperature is between those to setpoints both heating
and cooling outputs are not working, the room temperature is in the Zero energy band. When the
room temperature drops below the heating setpoint, output 2 output will energize. When the
room temperature rises above the cooling setpoint, output 1 will energize.
2 settings values are available for Zero energy band: 3°F(1.5°C) or 5°F(3°C).
4
2. Control Sequences
All the control sequences and ramps are showed without any integral correction.
All the control sequences and ramps are showed in day mode operation. In night mode operation,
the cooling setpoint will go up and the heating setpoint will go down.
( T6984D & T7984B&C only )
The heating setpoint in night mode will go down by the NSB ( Night setback ) value.
The cooling setpoint in night mode will go up by the NSU ( Night setup ) value.
These values can be set using dip switch.
On model with 2 outputs, 1 in heating and the other in cooling ( T6984D & T7984B&C only ); it is
possible to adjust the value of the zero energy band ( deadband ) using dip switch.
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T6984A
SETPOINT DIAL CENTERED
Opened
100%
Device
opened
50 %
Closed
0%
Cooling only mode
Device
closed
Temperature increase
OUTPUT 1 FLOATING
SETPOINT DIAL CENTERED
To use the thermostat on
a heatingbonly application,
reverse the open/close wires
Opened
100%
Device
opened
50 %
Heating only mode
Closed
0%
Device
closed
OUTPUT 1 FLOATING
Temperature increase
T6984E
SETPOINT DIAL CENTERED
Opened
100%
Device Cooling mode
opened
Device
opened
50 %
Closed
0%
Device
closed
Temperature increase
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Device
closed
OUTPUT 1 FLOATING
6
Heating mode
changeover
input active
T6984D
Mode A ( jumper not installed )
Outout 1 floating in cooling mode
Output 2 on/off output in heating mode
SETPOINT DIAL DEFINITION
HEATING
SETPOINT
100%
Device
on
SETPOINT
CENTERED
IN ZERO
ENERGY BAND
COOLING
SETPOINT
Device
opened
50 %
Device
off
Device
closed
0%
OUTPUT 2
ON/OFF
OUTPUT 1
FLOATING
ZERO ENERGY BAND
Temperature increase
Mode B ( jumper installed )
Output 1 floating in heating mode
Output 2 on/off output in cooling mode
100%
Device
opened
SETPOINT DIAL DEFINITION
HEATING
SETPOINT
COOLING
SETPOINT
CENTERED
SETPOINT
IN ZERO
ENERGY BAND
Device
on
50 %
Device
closed
0%
Device
off
OUTPUT 1
FLOATING
OUTPUT 2
ON/OFF
ZERO ENERGY BAND
Temperature increase
7
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T7984A
SETPOINT DIAL CENTERED
Opened
100%
Device
opened Cooling mode
10 Vdc
Device
opened
10 Vdc
50 %
Closed
0%
Device
closed
2 Vdc
Temperature increase
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Device
closed
2 Vdc
OUTPUT 1 ANALOG
8
Heating mode
changeover
input active
T7984B
Mode A ( jumper not installed )
Output 1 analog in cooling mode
Output 2 on/off in heating mode
SETPOINT DIAL DEFINITION
HEATING
SETPOINT
100%
Device
on
SETPOINT
CENTERED
IN ZERO
ENERGY BAND
50 %
Device
off
0%
COOLING
SETPOINT
Device
opened
10 vdc
Device
closed
2 Vdc
OUTPUT 2
ON/OFF
OUTPUT 1
ANALOG
ZERO ENERGY BAND
Temperature increase
Mode B ( jumper installed )
Output 1 analog in heating mode
Output 2 on/off in cooling mode
100%
Device
opened
10 Vdc
SETPOINT DIAL DEFINITION
HEATING
SETPOINT
COOLING
SETPOINT
CENTERED
SETPOINT
IN ZERO
ENERGY BAND
50 %
Device
closed
2 Vdc
0%
Device
on
Device
off
OUTPUT 1
ANALOG
OUTPUT 2
ON/OFF
ZERO ENERGY BAND
Temperature increase
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T7984C
Changeover input
for output 1 not active
Output 1 analog in cooling mode
Output 2 analog in heating mode
SETPOINT DIAL DEFINITION
HEATING
SETPOINT
100%
Device
opened
10 vdc
50 %
SETPOINT
CENTERED
IN ZERO
ENERGY BAND
Device
closed
2 Vdc
0%
COOLING
SETPOINT
Device
opened
10 vdc
Device
closed
2 Vdc
OUTPUT 2
ANALOG
OUTPUT 1
ANALOG
ZERO ENERGY BAND
Temperature increase
Changeover input
for output 1 activated
Output 1 analog in heating mode
Output 2 analog in heating mode
100%
Device
opened
10 Vdc
SETPOINT DIAL DEFINITION
HEATING
SETPOINT
COOLING
SETPOINT
CENTERED
SETPOINT
IN ZERO
Device
opened
ENERGY BAND
10 Vdc
50 %
Device
closed
2 Vdc
Device
closed
2 Vdc
0%
OUTPUT 1
ANALOG
OUTPUT 2
ANALOG
ZERO ENERGY BAND
Temperature increase
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10
3. Screw Terminals Arrangement
T6984 Series Thermostats
Motor open
Output 1
Motor close
T6984A
24 Vac
Power supply
( 0 Vac )
Internal sensor
Sensor input
T6984D
Mode input
( 0 Vac )
NSB input
Output 2
On/off
Motor open
Output 1
Motor close
24 Vac
Power supply
( 0 Vac )
Internal sensor
Sensor input
T6984E
Changeover
input for Out 1
( 0 Vac )
11
Motor open
Output 1
Motor close
24 Vac
Power supply
( 0 Vac )
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T7984 Series Thermostats
T7984A
Remote
sensor input
( 0 Vac )
Not used
Output 1
2-10 Vdc
Changeover
input for Out 1
24 Vac
Power supply
( 0 Vac )
Output 2
On/off
Output 1
2-10 Vdc
T7984B
Remote
sensor input
( 0 Vac )
NSB input
Mode input
24 Vac
Power supply
( 0 Vac )
Output 2
2-10 Vdc
Output 1
2-10 Vdc
T7984C
Remote
sensor input
Changeover
input for Out 1
( 0 Vac )
24 Vac
Power supply
( 0 Vac )
NSB input
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12
4. Thermostat Dip Switch Definition
T6984 Series
T6984D only
OUTPUT 2 ON/OFF CPH
For more information, see on/off output cycle per hour application note.
CYCLES/HOUR
S1
It is possible to fix the number of time per hour the on/off
FAST 8 CPH
1
output will be energized.
SLOW 4 CPH
0
T6984D only
ZERO ENERGY BAND
ZEB
5 °F ( 3 °C )
3 °F ( 1.5 °C )
S2
1
0
On models which have 2 outputs, 1 for cooling and 1 for
heating. It is possible to adjust the zero energy band value
( dead band between heating and cooling setpoints )
T6984D only
SETPOINT DIAL DEFINITION
For more information, see setpoint dial definition & setpoint limitation application note.
Models with cooling and heating outputs
DEFINITION
S3
S4
75 °F OVERRIDE
1
1
⇒ Setpoint dial centered, 75°F limitation not active
HEATING DIAL
0
1
⇒ Setpoint dial defined as heating, 75°F limitation active
COOLING DIAL
1
0
⇒ Setpoint dial defined as cooling, 75°F limitation active
CENTERED H/C
0
0
⇒ Setpoint dial centered, 75°F limitation active
T6984A, D & E
MOTOR TIME
SECONDS
420
240
150
120
90
60
30
20
S5
1
0
1
0
0
1
0
1
S6
1
1
0
0
0
1
1
0
S7
1
1
1
0
1
0
0
0
Motor timing dip switch setting must match
the used actuator maximum running time.
The motor maximum timing is the
maximum running time that the actuator
may take to complete full stroke or
maximum rotation. For optimum control,
select a dip switch timing setting which is
equal or slightly shorter than the actual
maximum running time.
T6984D only
DAY/NIGHT SETBACK
HEAT SETBACK
10 °F ( 5 °C )
5 °F ( 3 °C )
ON = 1
OFF = 0
1
2
3
4
5
6
7
8
COOL SETUP
20 °F (10 °C )
5 °F ( 3 °C )
S8
1
0
Night mode setpoints can be adjusted
to different values depending on the
application.
DIP SWITCH ADJUSTMENTS FOR T6984D
SETPOINT DIAL DEFINITION
NIGHT HEATING
SETPOINT
Device
on
DAY HEATING
SETPOINT
SETPOINT
CENTERED
IN ZERO
ENERGY BAND
HEAT SETBACK
Device
opened
NIGHT COOLING
SETPOINT
Device
closed
Device
off
OUTPUT 2
ON/OFF
DAY COOLING
SETPOINT
Temperature increase
ZERO ENERGY BAND
13
OUTPUT 1
FLOATING
COOL SETUP
63-8592
T7984 Series
T7984B only
OUTPUT 2 ON/OFF CPH
For more information, see on/off output cycle per hour application note.
CYCLES/HOUR
S1
It is possible to fix the number of time per hour the on/off
FAST 8 CPH
1
output will be energized.
SLOW 4 CPH
0
T7984B & C only
ZERO ENERGY BAND
ZEB
5 °F ( 3 °C )
3 °F ( 1.5 °C )
S2
1
0
On models which have 2 outputs, 1 for cooling and 1 for
heating. It is possible to adjust the zero energy band value
( dead band between heating and cooling setpoints )
T7984B & C only
SETPOINT DIAL DEFINITION
For more information, see setpoint dial definition & setpoint limitation application note.
Models with cooling and heating outputs
DEFINITION
S3
S4
75 °F OVERRIDE
1
1
⇒ Setpoint dial centered, 75°F limitation not active
HEATING DIAL
0
1
⇒ Setpoint dial defined as heating, 75°F limitation active
COOLING DIAL
1
0
⇒ Setpoint dial defined as cooling, 75°F limitation active
CENTERED H/C
0
0
⇒ Setpoint dial centered, 75°F limitation active
T7984B & C only
DAY/NIGHT SETBACK
HEAT SETBACK
10 °F ( 5 °C )
5 °F ( 3 °C )
COOL SETUP
20 °F (10 °C )
5 °F ( 3 °C )
S5
1
0
Night mode setpoints can be adjusted
to different values depending on the
application.
T7984A, B & C
REMOTE SENSOR
On model T7984A, switch S7 & S8 are not used.
MAIN SENSOR
S6
For duct return air or remote room sensor control only. Do
not use remote sensor in supply or discharge air control
LOCAL INTERNAL
1
applications.
REMOTE SENSOR
0
ON = 1
OFF = 0
1
2
3
4
5
6
DIP SWITCH ADJUSTMENTS FOR T7984B & C
SETPOINT DIAL DEFINITION
NIGHT HEATING
SETPOINT
Device
100 %
DAY HEATING
SETPOINT
SETPOINT
CENTERED
IN ZERO
ENERGY BAND
OUTPUT 2
HEAT SETBACK
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Device
100 %
Device
0%
Device
0%
ON/OFF OR ANALOG
DAY COOLING
SETPOINT
Temperature increase
ZERO ENERGY BAND
14
OUTPUT 1
ANALOG
COOL SETUP
NIGHT COOLING
SETPOINT
5. Application Notes
5.1.
PI control vs. On/Off control
5.2.
Modulating floating control vs. Analog 2 to 10 Vdc control
5.3.
Setpoint dial definition & setpoint limitation
5.4.
4 to 20 ma. output models
5.5.
Installation of auxiliary screw terminals and
general wiring information
5.6.
On/off output, cycle per hour dip switch setting
15
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5.1. PI Control vs. On/Off Control
PI control stands for Proportional + Integral control. The T6984 & T7984 series thermostat use
advanced PI control algorithms with a small but powerful microcomputer built in the electronic
circuit board. These provide a precise temperature control and eliminate wasted heating or cooling
energy in conventional thermostats. As a result, the room occupant is able to adjust the desired
heating or cooling setpoint to is optimum comfort setting. The result is 5% to 10% energy saving
with improved comfort.
On/Off mechanical thermostats waste energy
Comfort
Temperature
Temperature
Time
PI electronic controls do not waste energy
As an analogy to PI control thermostats.
The following analogy may be useful in explaining PI Three Point Floating or PI Analog 2 to 10
VDC control.
Think of the PI temperature control as a cruise control in a car, which is also a PI type control.
The damper or valve position is equivalent to: the pedal position or engine output
The room temperature is equivalent to: the actual speed of the car
The thermostat setpoint is equivalent to: the desired cruise speed
Q. What is the position of the of the pedal when you are doing 60 MPH ?
A. You don’t know and you don’t care. The pedal position will depend on such things as wind
speed, fuel used, engine temperature and efficiency, the gear that the transmission is in, the
incline of the road, turbulence caused by traffic, number of passenger and total load, if the air
conditioning is on or not, if the windows are open, the tires used and the tire pressure and probably
a million other things !
You know that the cruise control will work adequately in a variety of situations, although sometimes
resulting in very small control errors when things are changing ( under dynamic conditions ). If all is
constant you may notice that the pedal position is constant.
Any variation in the actual load on the engine due to a variation of any parameter will cause
the cruise control to readjust its output to maintain its desired setpoint.
Any residual error after readjustment is corrected by the integral action only.
The floating & Analog 2 to 10 VDC PI controls will provide precise control of room temperature and
maintain setpoint more accurately.
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16
5.2. Modulating Floating Control T6984
vs.
Analog 2 To 10 VDC Control T7984
Both T6984 & T7984 series thermostat use PI control and will fully modulate end devices. Both
type of output are able to position the end device according to the actual demand from their PI
control loop.
Q. Is one better than the other ?
A. No both are fully modulating, although one or the other is more recommended in certain cases.
The PI floating controls will provide precise control of room temperature with lower cost
three point floating motorized valve and damper actuators.
Use analog 2 to 10 VDC control when
You are controlling more than 1 valve or damper
actuator
When you are using spring return end devices
When you are using large end devices
When you are less familiar with electronic
controls ( at first, they are easier to start-up and
troubleshoot )
Use floating control when
You are controlling only 1 valve or damper
actuator
When you are using end devices with no fail
safe
When the total installed cost needs to be lower
When you are using small end devices
When you are more familiar with electronic
controls ***
*** It is important when starting-up and commissioning T6984 thermostats series that uses
modulating floating control to properly setup the actuator direction or rotation versus the thermostat
open/close direction of rotation.
Open contact on the thermostat
Needs to open the end device when activated
Close contact on the thermostat
Needs to close the end device when activated
If the rotation is reversed, the controls will not work properly.
If the rotation is reversed, reverse the Open/Close wiring or flip the Left/Right switch on the
actuator if it is equipped with one.
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5.3. Setpoint Dial Definition & Setpoint Limitation
Valid for these model only: T6984D & T7984B,C
Setpoint dial definition:
On thermostats which have output 1 in cooling mode and a output 2 in heating mode or vice versa.
The setpoint dial definition needs to be adjusted. These thermostats have 2 distinct setpoints, one
for heating the other for cooling ( See the control curves section ). When the room temperature is
between those to AM both heating and cooling outputs are not working, the room temperature is in
the Zero energy band. When the room temperature drops below the heating setpoint, the Reheat
output will energize. When the room temperature rises above below the cooling setpoint, Stage 1
will energize. 2 settings values are available for Zero energy band: 3°F(1.5°C) or 5°F(3°C).
Q. On applications that have a different heating setpoint and cooling setpoint with a zero energy
band, how do you define thermostat dial on the cover of the thermostat ?
A. You need to set the proper dip switch to define the dial.
SETPOINT DIAL DEFINED AS CENTERED
100%
DIAL
TRUE HEATING
TRUE COOLING
SETPOINT
SETPOINT
SETPOINT
CENTERED
Device
Device
IN ZERO
off
opened
ENERGY BAND
50 %
Device
off
0%
Device
closed
REHEAT OUTPUT
STAGE 1
ZERO ENERGY BAND
SETPOINT DIAL DEFINED AS HEATING
100%
TRUE DIAL HEATING
SETPOINT
Device
off
TRUE COOLING
SETPOINT
Device
opened
50 %
100%
TRUE HEATING
SETPOINT
Device
off
TRUE DIAL COOLING
SETPOINT
Device
opened
50 %
Device
off
0%
Device
closed
Device
off
0%
REHEAT OUTPUT
STAGE 1
Device
closed
REHEAT OUTPUT
ZERO ENERGY BAND
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SETPOINT DIAL DEFINED AS COOLING
STAGE 1
ZERO ENERGY BAND
18
Setpoint limitation:
On thermostats which have Stage 1 ( cooling output ) and a Reheat output ( heating output ) The
setpoints can be limited electronically. These thermostats have 2 distinct setpoints, one for heating
the other for cooling.
These model only: T6984D & T7984B,C series thermostat feature a setpoint limitation which is
compatible with ASHRAE 90.1
Both setpoints are electronically limited to 75°F ( 24°C ). The cooling setpoint cannot be
lowered below 75°F and the heating setpoint cannot be raise above 75°F.
SETPOINT DIAL TURNED TO ITS LOWEST VALUE
HEATING
CENTERED
TRUE HEATING
SETPOINT
Device
COOLING
TRUE COOLING
SETPOINT Device
100%
100%
Device
0%
COOLING SETPOINT
CANNOT BE LOWER
THAN 75F
Device
0%
OUTPUT 2
OUTPUT1
ZERO ENERGY BAND
SETPOINT DIAL TURNED TO ITS HIGHEST VALUE
HEATING
CENTERED
TRUE HEATING
SETPOINT
Device
COOLING
TRUE COOLING
SETPOINT Device
100%
100%
HEATING SETPOINT
CANNOT BE HIGHER
THAN 75F
Device
0%
Device
0%
OUTPUT 2
OUTPUT 1
ZERO ENERGY BAND
MINIMUM HEATING SETPOINT
MINIMUM COOLING SETPOINT
IS DIAL MINIMUM SETTING
IS DIAL MAXIMUM SETTING
TRUE HEATING AND COOLING SETPOINTS ARE ELECTRONICALLY
LIMITED AT 75F WHEN DIAL IS ROTATED LEFT TO RIGHT
19
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This setpoint limitation can be overridden for system checkout by setting the dip switch to the
following: T6984D & T7984B,C set S=1 & S4=1. By doing this, the setpoint dial definition is now
centered in the middle of the zero energy band.
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20
5.4. 4 To 20 ma. Output
Valid for these model only: T7984A1040, T7984B1048 & T7984C1046.
1. Wiring:
4 to 20 mA
device
OR
Shunt resistor value to convert 4 to 20 mA
back to a 2 to 10 Vdc control signal
using a 500 Ohms 1/4 watt 5% resistor
4-20 mA output
+
+ +
+
2 to 10 Vdc
0 Vac common
-
-
-
-
2. Characteristics of 4 to 20 ma output is: maximum load 500 Ω at 20 ma. Voltage source is then
around 10 VDC. Normal load should be between 1 Ω and 500 Ω.
3. mA. signal can go as high as 25 mA du to normal component tolerance.
4. Analog voltage 2 to 10 VDC is also available for output 1 on another screw terminal but should
not be used simultaneously as the 4 to 20 mA output. Use either the 4 to 20 mA output or
the 2 to 10 VDC output, but not both.
Notes for model T7984C1046 only having the 4 to 20 mA output.
•
Analog voltage 0 to 10 VDC is also available for output 1 and output 2. Only 1 of these output
can be selected to work as the 4 to 20 mA output. Selection is done with dip switches.
Switch settings
Dip switch #7 off
Dip switch #8 off
Dip switch #7 on
Dip switch #8 off
Dip switch #7 off
Dip switch #8 on
Dip switch #7 on
Dip switch #8 on
•
Output 1
Analog 2 to 10 VDC
Output 2
Analog 2 to 10 VDC
4 to 20 mA
Do not use and wire Stage 1
2 to 10 VDC screw terminal
Analog 2 to 10 VDC
Analog 2 to 10 VDC
4 to 20 mA
Do not use and wire Reheat stage
2 to 10 VDC screw terminal
Never set the dip switches to this setting
Analog voltage 2 to 10 VDC is also available for output 1 and output 2 when they are
configured as 4 to 20 mA output. They should not be used simultaneously as the 4 to 20 mA
output. Use either the selected 4 to 20 mA output or the 2 to 10 VDC output, but not both.
21
63-8592
5.5. Installation Of Auxiliary Screw Terminals
And General Wiring Information
Auxiliary screw terminals:
Usage of auxiliary screw terminals strip in a junction box in the ceiling is recommended when
multiple wires are brought down at the thermostat. This is recommended for the following reasons:
•
•
•
•
It makes troubleshooting, startup and servicing easier.
Sometime the common & 24 Vac wires are used more
than once.
It brings down to the thermostat only 1 wire instead of
3 or 4. Junctions are easier to make at larger junction
screw terminals than at the smaller ones on the
thermostats.
Looping the same power supply, NSB contact and/or
changeover contact from thermostat to thermostat is a
lot easier.
24 Vac transformer
2 to 10 Vdc
L
A
N
B
NSB contact
24 Vac &
NSB contact
to other
thermostats
R
General wiring information:
•
Always read the instruction manuals of all components
installed in the system.
•
Always make a wiring diagram of the installation you want to make before starting to wire the
components.
•
All electronic thermostat need power supply in order to work. 19/30 Vac, 50/60 Hz, 2 VA
Be sure to respect the polarity between each thermostat when using a common transformer. (
24 Vac & Common ) The 2 VA rating does not include the power requirement of peripheral end
devices being controlled by the thermostat.
•
Never go above the rating of the triac outputs: 1.1A maximum inrush, 0.5A maximum running.
•
Polarity must also be respected between a T7984 series thermostat and the analog 2 to 10
VDC end device it its controlling.
•
It is important when starting-up and commissioning T6984 thermostats series that uses
modulating floating control to properly setup the actuator direction or rotation versus the
thermostat open/close direction of rotation.
•
For changeover application using sensors on T7984 models. 1 sensor per thermostat must be
used.
63-8592
22
Single transformer application
24 Vac transformer
L
N
A
B
NSB contact
Changeover contact
24 Vac
24 Vac
24 Vac
Common
Common
Common
NSB input
NSB input
NSB input
Changeover input
Changeover input
Changeover input
To other thermostats
23
For changeover application using sensors on T7984 models,
1 sensor per thermostat must be used.
Only central NSB contact or changeover contact can be used if necessary.
Do not ground any commonleg of any transformer to earth to prevent ground loop.
Usage of auxiliary screw terminals strip in a junction box is recommended
when multiple wires are brought down at the thermostat. This make
troubleshooting, startup and servicing easier.
Honeywell
Auxiliary screw terminals arrangement
Single transformer arrangement
63-8592
WIRING1
Feb 98
Rev.1
63-8592
Multiple transformer application
24 Vac transformer
NSB contact
Changeover contact
N
L
B
A
24 Vac transformer
N
24 Vac
24 Vac transformer
N
L
B A
24 Vac
L
B A
24 Vac
Common
Common
Common
NSB input
NSB input
NSB input
Changeover input
Changeover input
Changeover input
To other thermostats
24
For changeover application using sensors on T7984 models,
1 sensor per thermostat must be used.
Only central NSB contact or changeover contact can be used
if necessary.
Usage of auxiliary screw terminals strip in a junction box is
recommended when multiple wires are brought down at the thermostat.
This make troubleshooting, startup and servicing easier.
Honeywell
Auxiliary screw terminals arrangement
Multiple transformer arrangement
WIRNG1
March 97
Rev.0
5.6. On/off output, cycle per hour dip switch setting
Valid for these model only: T6984D & T7984B
It is possible to fix the number of time per hour the reheat end device will be energized. Those
setting are adjusted with dip switch.
2 different settings are possible:
4 cycles per hour or 8 cycles per hour
Use the following setting for the following reheat device applications:
4 cycles per hour
Anything using a gas fired or oil fired terminal
reheat device ( Never use 8 cycles per hour )
Any gear driven end device valve or damper
actuator
Properly sized electric base board strip
Properly sized electric duct heater
8 cycles per hour
N.C. 24 Vac thermal valve
( Hot wax thermal body valve )
Oversized capacity electric base board strip
Oversized capacity electric duct heater
If possible, always use the 4 cycles per hour setting. This setting increases the life span of the end
device by lowering the number of annual cycles.
25
63-8592
63-8592
26
6. Application Drawings For Valves
2 way and 3 way valves actuator
combinations for heating and/or cooling
Drawing
number
Valve: output 1
modulating
floating control
Changeover of
valve
(output 1) to
heating mode
Output 2
On/off
Night
setback
( NSB )
Optionnal remote
sensor ( not for
supply control
applications )
Thermostat
model
number
T6984 THERMOSTAT SERIES: VALVE APPLICATIONS
TO USE WITH VALVE ACTUATORS: VC6900 Series, VC6831 ( end switch model family ),
M6410, ML6161 & ML684
HWV100
HWV111
HWV141
Cooling or
heating only
Cooling or
heating only
Cooling &
heating →
HWV150
Cooling only
HWV170
Heating only
Drawing
number
Valve: output 1
Modulating 2 to
10 Vdc control
T6984A
Using a dry
contact
Changeover of
valve
( output 1 ) to
heating mode
X ( optionnal )
T6984E
X ( optionnal )
T6984E
On/off heating
only
On/off cooling
only
X
X ( optionnal )
T6984D
X
X ( optionnal )
T6984D
Output 2
T7984B
on/off
T7984C
analog
Night
setback
( NSB )
Optionnal remote
sensor ( not for
supply control
applications )
Thermostat
model
number
T7984 THERMOSTAT SERIES: VALVE APPLICATIONS
TO USE WITH VALVE ACTUATORS: VC7900 Series, ML7984, M7410E & ML7161
HWV210
HWV240
Cooling or
heating only
Cooling &
heating →
HWV250
Cooling only
HWV270
Heating only
HWV280
Cooling &
heating →
HWV282
Analog cooling
only
Analog cooling
only
HWV284
Using a dry
contact or
sensor
Using a dry
contact or
sensor
X ( optionnal )
T7984A
X ( optionnal )
T7984A
On/off heating
only
On/off cooling
only
X
X ( optionnal )
T7984B
X
X ( optionnal )
T7984B
Analog
heating only
X
X ( optionnal )
T7984C
Analog
heating only
Analog
heating only
X
X ( optionnal )
T7984C
X
X ( optionnal )
T7984C
27
63-8592
COOLING APPLICATION
2 Way or 3 way valve
Common
24 Vac transformer
L
A
N
B
Open
Close
Modulating floating
valve actuator
0 Vac
24 Vac
Open
Output 1
Close
Sequence of operation for cooling:
Normal cooling mode, cold water supply
T6984A
On a rise of temperature from setpoint
1- Valve opens
For a heating only application:
Reverse open/close wires as shown
24 Vac
Open
Output 1
Close
On a drop of temperature from setpoint
1- Valve closes
Common
Open
Close
Floating valve actuator cooling
HWV100
63-8592
28
February 98
Rev.1
COOLING APPLICATION
2 Way or 3 way valve
Common
24 Vac transformer
L
A
N
B
Open
Close
Modulating floating
valve actuator
0 Vac
24 Vac
Open
Output 1
Close
Sequence of operation for cooling:
T6984E
Normal cooling mode, cold water supply
For a heating only application:
Install a jumper as shown
On a rise of temperature from setpoint
1- Valve opens
0 Vac
Changeover
input for Out 1
On a drop of temperature from setpoint
1- Valve closes
Remote room or remote duct return sensor
or
Remove factory
wire jumper
Internal sensor
Sensor input
0 Vac
Important:
Not for duct supply control applications
Floating valve actuator cooling
Important:
When remote sensor is not used, leave factory wire jumper installed
When remote sensor is used, remove factory wire jumper
and connect sensor as shown
HWV111
29
February 98
Rev.1
63-8592
COOLING & HEATING APPLICATION
c/w Changeover
2 Way or 3 way valve
Common
24 Vac transformer
L
A
N
B
Open
Close
Modulating floating
valve actuator
Changeover contact
0 Vac
24 Vac
Open
Output 1
Close
Sequence of operation:
Normal cooling mode, cold water supply
Changeover
input for Out 1
On a rise of temperature from setpoint
1- Valve opens
On a drop of temperature from setpoint
1- Valve closes
Changeover activated
Heating mode, hot water supply
T6984E
On a rise of temperature from setpoint
1- Valve closes
On a drop of temperature from setpoint
1- Valve opens
Remote room or remote duct return sensor
or
Remove factory
wire jumper
Internal sensor
Sensor input
0 Vac
Important:
Not for duct supply control applications
Floating valve actuator cooling
c/w heating changeover
Important:
When remote sensor is not used, leave factory wire jumper installed
When remote sensor is used, remove factory wire jumper
and connect sensor as shown
63-8592
HWV141
30
February 98
Rev.1
COOLING APPLICATION
2 Way or 3 way valve
Common
24 Vac transformer
L
A
N
B
Open
Close
NSB contact
Modulating floating
valve actuator
Hot water coil
24 Vac 2 position N.C. valve
0 Vac
24 Vac
Open
Output 1
Close
Output 2
on/off
NSB input
Electric duct heater
24 Vac relay without transformer
Sequence of operation:
R
T6984D
Normal cooling mode, cold water supply
On a rise of temperature from setpoint
1- Valve opens
On a drop of temperature from setpoint
1- Valve closes
2- Reheat energizes
Perimeter hot water coil
24 Vac 2 position N.C. valve
R
Remote room or remote duct return sensor
or
Remove factory
wire jumper
Electric base board
24 Vac relay without transformer
REHEAT OUTPUT DEVICES
Internal sensor
Sensor input
0 Vac
Important:
Not for duct supply control applications
Floating valve actuator cooling
Night setback & on/off reheat
Important:
When remote sensor is not used, leave factory wire jumper installed
When remote sensor is used, remove factory wire jumper
and connect sensor as shown
HWV150
31
February 98
Rev.1
63-8592
HEATING
2 Way or 3 way valve
COOLING
On/off DX stage
D
X
24 Vac
interface
relay
R
Common
24 Vac transformer
L
A
N
B
Open
Close
Modulating floating
valve actuator
NSB contact
0 Vac
24 Vac
Open
Output 1
Close
Output 2
on/off
NSB input
Sequence of operation:
On a rise of temperature from setpoint
1- DX cooling stage starts
0 Vac
Mode input
On a drop of temperature from setpoint
1- Heating valve opens
Mode jumper
installed
T6984D
Remote room or remote duct return sensor
or
Remove factory
wire jumper
Internal sensor
Sensor input
0 Vac
Important:
Not for duct supply control applications
Floating valve actuator heating
Night setback & on/off cooling
Important:
When remote sensor is not used, leave factory wire jumper installed
When remote sensor is used, remove factory wire jumper
and connect sensor as shown
63-8592
HWV170
32
February 98
Rev.1
COOLING APPLICATION
2 Way or 3 way valve
Common
24 Vac transformer
L
A
N
B
24 Vac
Input
2-10 Vdc
Modulating 2 to 10 Vdc
valve actuator
0 Vac
24 Vac
Output 1
2-10 Vdc
Sequence of operation for cooling:
T7984A
Normal cooling mode, cold water supply
For a heating only application:
Install a jumper as shown
On a rise of temperature from setpoint
1- Valve opens
0 Vac
Changeover
input for Out 1
On a drop of temperature from setpoint
1- Valve closes
Remote room or remote duct return sensor
0 Vac
Remote
sensor input
or
Important:
Not for duct supply control applications
2 to 10 Vdc valve actuator cooling
Important:
When remote sensor is not used, set dip switch #6 to position 1
When remote sensor is used, set dip switch #6 to position 0
HWV210
33
February 98
Rev.1
63-8592
COOLING & HEATING APPLICATION
c/w Changeover
2 Way or 3 way valve
Common
24 Vac transformer
L
A
N
B
24 Vac
Input
2-10 Vdc
Modulating 2 to 10 Vdc
valve actuator
Changeover contact
or
Changeover sensor
0 Vac
24 Vac
Output 1
2-10 Vdc
Sequence of operation:
Normal cooling mode, cold water supply
Changeover
input for Out 1
On a rise of temperature from setpoint
1- Valve opens
On a drop of temperature from setpoint
1- Valve closes
T7984A
Changeover activated
Heating mode, hot water supply
On a rise of temperature from setpoint
1- Valve closes
On a drop of temperature from setpoint
1- Valve opens
Remote room or remote duct return sensor
0 Vac
Remote
sensor input
or
Important:
Not for duct supply control applications
2 to 10 Vdc valve actuator cooling
c/w changeover
Important:
When remote sensor is not used, set dip switch #6 to position 1
When remote sensor is used, set dip switch #6 to position 0
63-8592
HWV240
34
February 98
Rev.1
COOLING APPLICATION
2 Way or 3 way valve
Common
24 Vac transformer
L
A
N
B
24 Vac
Input
2-10 Vdc
Modulating 2 to 10 Vdc
valve actuator
NSB contact
Hot water coil
24 Vac 2 position N.C. valve
0 Vac
24 Vac
Output 1
2-10 Vdc
Output 2
on/off
NSB input
Electric duct heater
24 Vac relay without transformer
Sequence of operation:
Normal cooling mode, cold water supply
R
T7984B
On a rise of temperature from setpoint
1- Valve opens
On a drop of temperature from setpoint
1- Valve closes
2- Reheat energizes
Perimeter hot water coil
24 Vac 2 position N.C. valve
R
Remote room or remote duct return sensor
Electric base board
24 Vac relay without transformer
0 Vac
Remote
sensor input
or
REHEAT OUTPUT DEVICES
Important:
Not for duct supply control applications
2 to 10 Vdc valve actuator cooling
Night setback & on/off reheat
Important:
When remote sensor is not used, set dip switch #6 to position 1
When remote sensor is used, set dip switch #6 to position 0
HWV250
35
February 98
Rev.1
63-8592
HEATING
2 Way or 3 way valve
COOLING
On/off DX stage
D
X
24 Vac
interface
relay
R
Common
24 Vac transformer
L
A
N
B
24 Vac
Input
2-10 Vdc
Modulating 2 to 10 Vdc
valve actuator
NSB contact
0 Vac
24 Vac
Output 1
2-10 Vdc
Output 2
on/off
NSB input
Sequence of operation:
On a rise of temperature from setpoint
1- DX cooling stage starts
0 Vac
Mode input
Mode jumper
installed
On a drop of temperature from setpoint
1- Heating valve opens
T7984B
Remote room or remote duct return sensor
0 Vac
Remote
sensor input
or
Important:
Not for duct supply control applications
2 to 10 Vdc valve actuator heating
Night setback & on/off cooling
Important:
When remote sensor is not used, set dip switch #6 to position 1
When remote sensor is used, set dip switch #6 to position 0
63-8592
HWV270
36
February 98
Rev.1
COOLING & HEATING APPLICATION
c/w Changeover
2 Way or 3 way valve
Common
24 Vac transformer
24 Vac
Input
2-10 Vdc
Modulating 2 to 10 Vdc
valve actuator
A
L
B
NSB contact
Changeover contact
or
Changeover sensor
N
0 Vac
24 Vac
Output 1
2-10 Vdc
Output 2
2-10 Vdc
Hot water coil
Modulating 2 to 10 Vdc valve
Sequence of operation:
Normal cooling mode, cold water supply
NSB input
Changeover
input for Out 1
On a rise of temperature from setpoint
1- Valve opens
On a drop of temperature from setpoint
1- Valve closes
2- Reheat energizes
T7984C
Changeover activated
Heating mode, hot water supply
Electric base board
Modulating 2 to 10 Vdc SCR
On a rise of temperature from setpoint
1- Valve closes
SCR
Power Control
On a drop of temperature from setpoint
1- Valve opens
2- Reheat energizes
Remote room or remote duct return sensor
Perimeter hot water coil
Modulating 2 to 10 Vdc valve
0 Vac
Remote
sensor input
or
REHEAT OUTPUT DEVICES
Important:
Not for duct supply control applications
2 to 10 Vdc valve actuator cooling
c/w changeover
Night setback & modulating reheat
HWV280
Rev.1
February 98
Important:
When remote sensor is not used, set dip switch #6 to position 1
When remote sensor is used, set dip switch #6 to position 0
37
63-8592
COOLING APPLICATION
2 Way or 3 way valve
Common
24 Vac transformer
L
A
N
B
24 Vac
Input
2-10 Vdc
Modulating 2 to 10 Vdc
valve actuator
NSB contact
0 Vac
Hot water coil
Modulating 2 to 10 Vdc valve
24 Vac
Output 1
2-10 Vdc
Output 2
2-10 Vdc
NSB input
Sequence of operation:
Normal cooling mode, cold water supply
Electric base board
Modulating 2 to 10 Vdc SCR
T7984C
On a rise of temperature from setpoint
1- Valve opens
On a drop of temperature from setpoint
1- Valve closes
2- Reheat energizes
SCR
Power Control
Remote room or remote duct return sensor
Perimeter hot water coil
Modulating 2 to 10 Vdc valve
0 Vac
Remote
sensor input
or
REHEAT OUTPUT DEVICES
Important:
Not for duct supply control applications
2 to 10 Vdc valve actuator cooling
Night setback & modulating reheat
Important:
When remote sensor is not used, set dip switch #6 to position 1
When remote sensor is used, set dip switch #6 to position 0
63-8592
HWV282
38
February 98
Rev.1
COOLING VALVE
2 Way or 3 way valve
Common
24 Vac
Input
2-10 Vdc
HEATING VALVE
2 Way or 3 way valve
Modulating 2 to 10 Vdc
valve actuator
Common
24 Vac
Input
2-10 Vdc
Modulating 2 to 10 Vdc
valve actuator
24 Vac transformer
A
L
B
N
NSB contact
0 Vac
24 Vac
Output 1
2-10 Vdc
Output 2
2-10 Vdc
Sequence of operation:
Normal cooling mode, cold water supply
NSB input
On a rise of temperature from setpoint
1- Cooling valve opens
On a drop of temperature from setpoint
1- Heating valve opens
T7984C
Remote room or remote duct return sensor
0 Vac
Remote
sensor input
or
Important:
Not for duct supply control applications
2 to 10 Vdc valve actuator cooling
2 to 10 Vdc valve actuator heating
Night setback
HWV284
Rev.1
February 98
Important:
When remote sensor is not used, set dip switch #6 to position 1
When remote sensor is used, set dip switch #6 to position 0
39
63-8592
63-8592
40
7. Application Drawings For Boxes:
Zone dampers, By-pass, Pressure dependent VAV & Mechanically
Compensated VAV
Drawing
number
Box: output 1
modulating
floating control
Changeover of
Box
( output 1 ) to
heating mode
Output 2
On/off
Night
setback
( NSB )
Optional
remote
sensor ( not
for supply
control
applications )
Thermostat
model
number
T6984 THERMOSTAT SERIES: ZONE DAMPER APPLICATIONS
TO USE WITH VAV ACTUATORS: ML6161
HWB100
HWB111
HWB141
Cooling only
Cooling only
Cooling & heating
→
HWB172
Cooling only
Drawing
number
Box: output 1
Modulating 2 to
10 Vdc control
X ( optional )
X ( optional )
T6984A
T6984E
T6984E
X
X ( optional )
T6984D
Night
setback
( NSB )
Optional
remote
sensor ( not
for supply
control
applications )
Thermostat
model
number
Using a dry
contact
Heating only
Changeover of
box
( output 1 ) to
heating mode
Output 2
T7984B on/off
T7984C analog
T7984 THERMOSTAT SERIES: ZONE DAMPER APPLICATIONS
TO USE WITH VAV ACTUATORS: ML7161
HWB210
HWB240
Cooling only
Cooling & heating
→
HWB272
Cooling only
On/off heating
only
HWB282
Cooling only
HWB280
Cooling & heating
→
Analog heating
only
Analog heating
only
X ( optional )
X ( optional )
T7984A
T7984A
X
X ( optional )
T7984B
X
X ( optional )
T7984C
X
X ( optional )
T7984C
Using a dry
contact or sensor
Using a dry
contact or sensor
41
63-8592
COOLING APPLICATION
Zone damper
Common
24 Vac transformer
L
A
N
B
Open
Close
Modulating floating
VAV actuator
0 Vac
24 Vac
Open
Output 1
Close
Sequence of operation:
T6984A
Normal cooling mode, cold air supply
On a rise of temperature from setpoint
1- Box opens
On a drop of temperature from setpoint
1- Box closes
Floating actuator cooling
HWB100
63-8592
42
February 98
Rev.1
COOLING APPLICATION
Zone damper
Common
24 Vac transformer
L
A
N
B
Open
Close
Modulating floating
VAV actuator
0 Vac
24 Vac
Open
Output 1
Close
Sequence of operation:
T6984E
Normal cooling mode, cold air supply
On a rise of temperature from setpoint
1- Box opens
On a drop of temperature from setpoint
1- Box closes
Remote room or remote duct return sensor
or
Remove factory
wire jumper
Internal sensor
Sensor input
0 Vac
factory wire jumper installed
Important:
Not for duct supply control applications
Floating actuator cooling
Important:
When remote sensor is not used, leave factory wire jumper installed
When remote sensor is used, remove factory wire jumper
and connect sensor as shown
43
HWB111
February 98
Rev.1
63-8592
COOLING & HEATING APPLICATION
c/w Changeover
Zone damper
Common
24 Vac transformer
L
A
N
B
Open
Close
Modulating floating
VAV actuator
Changeover contact
0 Vac
24 Vac
Open
Output 1
Close
Sequence of operation:
Normal cooling mode, cold air supply
On a rise of temperature from setpoint
1- Box opens
Changeover
input for Out 1
On a drop of temperature from setpoint
1- Box closes
Changeover activated
Heating mode, hot air supply
On a rise of temperature from setpoint
1- Box closes
T6984E
On a drop of temperature from setpoint
1- Box opens
Remote room or remote duct return sensor
or
Remove factory
wire jumper
Internal sensor
Sensor input
0 Vac
Important:
Not for duct supply control applications
Important:
When remote sensor is not used, leave factory wire jumper installed
When remote sensor is used, remove factory wire jumper
and connect sensor as shown
63-8592
44
Floating actuator cooling
c/w changeover
HWB141
February 98
Rev.1
COOLING APPLICATION
Zone damper
Common
24 Vac transformer
L
A
N
B
Open
Close
Modulating floating
VAV actuator
NSB contact
Hot water coil
24 Vac 2 position N.C. valve
0 Vac
24 Vac
Open
Output 1
Close
Output 2
on/off
NSB input
Electric duct heater
24 Vac relay without transformer
Sequence of operation:
R
T6984D
Normal cooling mode, cold air supply
On a rise of temperature from setpoint
1- Box opens
On a drop of temperature from setpoint
1- Box closes
2- Reheat energizes
Perimeter hot water coil
24 Vac 2 position N.C. valve
R
Remote room or remote duct return sensor
or
Remove factory
wire jumper
Electric base board
24 Vac relay without transformer
REHEAT OUTPUT DEVICES
Internal sensor
Sensor input
0 Vac
Important:
Not for duct supply control applications
Important:
When remote sensor is not used, leave factory wire jumper installed
When remote sensor is used, remove factory wire jumper
and connect sensor as shown
45
Floating actuator cooling
Night setback & on/off reheat
HWB172
February 98
Rev.1
63-8592
COOLING APPLICATION
Zone damper
Common
24 Vac transformer
L
A
N
B
24 Vac
Input
2-10 Vdc
Modulating 2 to 10 Vdc
VAV actuator
0 Vac
24 Vac
Output 1
2-10 Vdc
Sequence of operation:
T7984A
Normal cooling mode, cold air supply
On a rise of temperature from setpoint
1- Box opens
On a drop of temperature from setpoint
1- Box closes
Remote room or remote duct return sensor
0 Vac
Remote
sensor input
or
Important:
Not for duct supply control applications
Analog 2-10 Vdc actuator cooling
Important:
When remote sensor is not used, set dip switch #6 to position 1
When remote sensor is used, set dip switch #6 to position 0
63-8592
HWB210
46
February 98
Rev.1
COOLING & HEATING APPLICATION
c/w Changeover
Zone damper
Common
24 Vac transformer
L
A
N
B
24 Vac
Input
2-10 Vdc
Modulating 2 to 10 Vdc
VAV actuator
Changeover contact
or
Changeover sensor
0 Vac
24 Vac
Output 1
2-10 Vdc
Sequence of operation:
Normal cooling mode, cold air supply
Changeover
input for Out 1
On a rise of temperature from setpoint
1- Box opens
On a drop of temperature from setpoint
1- Box closes
T7984A
Changeover activated
Heating mode, hot air supply
On a rise of temperature from setpoint
1- Box closes
On a drop of temperature from setpoint
1- Box opens
Remote room or remote duct return sensor
0 Vac
Remote
sensor input
or
Important:
Not for duct supply control applications
Important:
When remote sensor is not used, set dip switch #6 to position 1
When remote sensor is used, set dip switch #6 to position 0
47
Analog 2-10 Vdc actuator cooling
c/w changeover
HWB240
February 98
Rev.1
63-8592
COOLING APPLICATION
Zone damper
Common
24 Vac transformer
L
A
N
B
24 Vac
Input
2-10 Vdc
Modulating 2 to 10 Vdc
VAV actuator
NSB contact
Hot water coil
24 Vac 2 position N.C. valve
0 Vac
24 Vac
Output 1
2-10 Vdc
Output 2
on/off
NSB input
Electric duct heater
24 Vac relay without transformer
Sequence of operation:
R
T7984B
Normal cooling mode, cold air supply
On a rise of temperature from setpoint
1- Box opens
On a drop of temperature from setpoint
1- Box closes
2- Reheat energizes
Perimeter hot water coil
24 Vac 2 position N.C. valve
R
Remote room or remote duct return sensor
Electric base board
24 Vac relay without transformer
0 Vac
Remote
sensor input
or
REHEAT OUTPUT DEVICES
Important:
Not for duct supply control applications
Analog 2-10 Vdc actuator cooling
Night setback & on/off reheat
Important:
When remote sensor is not used, set dip switch #6 to position 1
When remote sensor is used, set dip switch #6 to position 0
63-8592
HWB272
48
February 98
Rev.1
COOLING & HEATING APPLICATION
c/w Changeover
Zone damper
Common
24 Vac transformer
L
24 Vac
Input
2-10 Vdc
Modulating 2 to 10 Vdc
VAV actuator
A
B
NSB contact
Changeover contact
or
Changeover sensor
N
0 Vac
Hot water coil
Modulating 2 to 10 Vdc valve
24 Vac
Output 1
2-10 Vdc
Output 2
2-10 Vdc
Sequence of operation:
NSB input
Normal cooling mode, cold air supply
Changeover
input for Out 1
On a rise of temperature from setpoint
1- Box opens
On a drop of temperature from setpoint
1- Box closes
2- Reheat energizes
Electric base board
Modulating 2 to 10 Vdc SCR
T7984C
Changeover activated
Heating mode, hot air supply
On a rise of temperature from setpoint
1- Box closes
SCR
Power Control
On a drop of temperature from setpoint
1- Box opens
2- Reheat energizes
Remote room or remote duct return sensor
0 Vac
Remote
sensor input
Perimeter hot water coil
Modulating 2 to 10 Vdc valve
REHEAT OUTPUT DEVICES
or
Analog 2-10 Vdc actuator cooling
c/w changeover
Night setback & modulating reheat
Important:
Not for duct supply control applications
Important:
When remote sensor is not used, set dip switch #6 to position 1
When remote sensor is used, set dip switch #6 to position 0
HWB280
49
February 98
Rev.1
63-8592
COOLING APPLICATION
Zone damper
Common
24 Vac transformer
L
A
N
B
24 Vac
Input
2-10 Vdc
Modulating 2 to 10 Vdc
VAV actuator
NSB contact
0 Vac
Hot water coil
Modulating 2 to 10 Vdc valve
24 Vac
Output 1
2-10 Vdc
Output 2
2-10 Vdc
NSB input
Sequence of operation:
Electric base board
Modulating 2 to 10 Vdc SCR
T7984C
Normal cooling mode, cold air supply
On a rise of temperature from setpoint
1- Box opens
SCR
Power Control
On a drop of temperature from setpoint
1- Box closes
2- Reheat energizes
Remote room or remote duct return sensor
Perimeter hot water coil
Modulating 2 to 10 Vdc valve
0 Vac
Remote
sensor input
or
REHEAT OUTPUT DEVICES
Important:
Not for duct supply control applications
Analog 2-10 Vdc actuator cooling
Night setback & modulating reheat
Important:
When remote sensor is not used, set dip switch #6 to position 1
When remote sensor is used, set dip switch #6 to position 0
63-8592
HWB282
50
February 98
Rev.1
8. Checkout & Start Up Procedures
Electronic thermostats require special care for wiring and startup. To avoid problems, carefully follow the
enclosed procedures.
Be sure to have all the literature on hand for all components installed: thermostat, actuators and relays.
Look at the wiring diagrams, and study them carefully. Be sure that you understand how the system is supposed to
work.
Make the wiring according to the wiring diagrams. Respect polarity for 24 Vac power terminals between multiple
thermostats if the same transformer is used.
VERIFICATION OF WIRING
Test the following directly on the thermostat screw terminals or auxiliary screw terminals.
POWER SUPPLY:
Confirm that you have a proper power supply to the thermostat.
With an electronic meter, verify that the power supply is: 19/30 Vac, 50/60 Hz
Be sure to have at least 2 VA available for the thermostat at the transformer. Remember that this current draw is for the
thermostat only, the transformer should be sized accordingly to the current draw of all the components of the system:
thermostat, actuator, relays, etc...
T6984 FLOATING ACTUATOR:
The thermostat uses 2 triacs ( electronic contacts ) to open and close the floating actuator.
To confirm that the actuator is working properly and operating in the right direction do the following:
Install a jumper across the Common and Open screw terminals, the actuator should open.
Install a jumper across the Common and Close screw terminals, the actuator should close.
The open/close output 1 uses electronic triacs. A triac is the equivalent of an electronic dry contact.
These triac outputs are protected with self resetting fuses and are rated at 1.1A maximum inrush, 0.5A maximum
running. Do not go above the triacs rating.
When they are energized by the thermostat, their switching action is as follow:
0 Vac Common
24 Vac
A
L
B
N
24 Vac transformer
Motor close
Motor open
Common
Actuator
Close
T6984
Open
1. The leg of the transformer being switched by the triacs is the Common leg.
2. On the T6984, the common of the floating actuator being used is wired to the 24 Vac leg of the thermostat
3. If the rotation is reversed, the controls will not work properly. If the rotation is reversed, reverse the Open/Close
wiring or flip the Left/Right switch on the actuator if it is equipped with one.
51
63-8592
ON/OFF OUTPUT 2 ( T6984D and T7984B models only )
The thermostat use a triac to energize the on/off output 2.
To confirm that the reheat is working properly do the following:
Install a jumper across the Common and On/off screw terminals, the output should energize.
The On/off output 2 uses an electronic triac. A triac is the equivalent of an electronic dry contact.
These triac outputs are protected with self resetting fuses and are rated at 1.1A maximum inrush, 0.5A maximum
running. Do not go above the triacs rating.
When they are energized by the thermostat, their switching action is as follow:
0 Vac Common
24 Vac
A
L
B
N
24 Vac transformer
Reheat
R
24 Vac reheat device
1. The leg of the transformer being switched by the triac is the Common leg.
STARTUP
Important notes:
• Be sure to have the proper thermostat for the proper end devices.
• ( Do you have the good components for your application )
• Be sure that the dip switch are set properly for your application.
• For these model with 2 outputs: T6984D & T7984B & C. The setpoint limitation must be overridden for system
checkout by setting the dip switch to the following: set S=1 & S4=1.
POWER UP DELAY ON T6984: When powering up the thermostat, the actuator will not respond to a changing setpoint
demand for X minutes. X being the maximum selected running time dip switch setting of the floating actuator. The
micro-processor is making sure that the actuator is fully closed before taking control. So for X minutes after powering
up the thermostat the actuator will not respond to a setpoint change.
63-8592
52
OUTPUT 1 & OUTPUT 2 TESTING
1. CHANGEOVER: If the thermostat is equipped with automatic changeover, disconnect any wires at the changeover input.
2. NSB: If the thermostat is equipped NSB, disconnect any wires at the NSB input.
3. For model with 2 outputs: ( T6984D & T7984B & C ) The setpoint limitation must be overridden for system
checkout by setting the dip switch to the following: set S=1 & S4=1.
4. The room temperature needs to be between 60 to 80°F
The following procedures can be used to test output 1 of the thermostat.
Also monitor the internal service LED to confirm the operations.
T6984 Actuator ( output 1 ) in cooling mode
Output 2 internal LED
Output 1 actuator Output 1 internal LED
Output 2:
if used
Red ( Off )
Minimum position
Opening
Green on (opening)
Not energized
Red ( On )
Maximum position
Closing
Yellow on (closing)
Energized
T6984 Actuator ( output 1 ) in heating mode
Install a jumper across the Common and changeover screw terminals
Output 2 internal LED
Rotate setpoint dial to: Output 1 actuator Output 1 internal LED
Output 2:
if used
Red ( Off )
Minimum position
Closing
Yellow on (closing)
Not energized
Red ( On )
Maximum position
Opening
Green on (opening)
Energized
Rotate setpoint dial to:
T7984 Actuator ( output 1 ) in cooling mode
Output 2 internal LED
Output 1 actuator Output 1 internal LED
Output 2:
if used
Red ( Off )
Minimum position
Opening
Green on (opening)
Not energized
Red ( On )
Maximum position
Closing
Green off (closing)
Energized
T7984 Actuator ( output 1 ) in heating mode
Install a jumper across the Common and changeover screw terminals
Output 2 internal LED
Rotate setpoint dial to: Output 1 actuator Output 1 internal LED
Output 2:
if used
Red ( Off )
Minimum position
Closing
Green off (closing)
Not energized
Red ( On )
Maximum position
Opening
Green on (opening)
Energized
Rotate setpoint dial to:
When done, connect back all wires and reset setpoint dial definition dip switch to their intended value.
53
63-8592
63-8592
54
55
63-8592
Home and Building Control
Honeywell Inc.
Honeywell Plaza
P.O. Box 524
Minneapolis, MN 55408-0524
Home and Building Control
Honeywell Limited-Honeywell Limitee
155 Gordon Baker Road
North York, Ontario
M2H 3N7
Honeywell Latin American Region
480 Sawgrass Corporate Parkway
Suite 200
Sunrise, FL 33325
Honeywell Europe S.A.
3 Avenue du Bourget
1140 Brussels
Belgium
63-8592
M.L.
2-98
Honeywell Asia Pacific Inc.
Room 3213-3225
Sun Hung Kai Centre
No. 30 Harbour Road
Wanchai
Hong Kong
Printed in U.S.A. on recycled
paper containing at least 10%
post-consumer paper fibers.
www.honeywell.com
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