63-8592 - application manual for t6984 & t7984 series
TRANSCRIPT
63-8592
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
• 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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1. Terms And Definitions
Changeover input
Heat/Coolchangeover ofouput 1
Models T6984E, T7984A & C all have the possibility of changeover for output 1. Automaticchangeover is used on systems were a valve or a VAV unit may have cold and hot water or air inthe 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 thefunction of output 1 to heating mode ( Reverse Acting ) so that the thermostat can use the enddevice 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 andfunction 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 willreverse modulating output 1 to operate as a heating only output & the on/off output 2 as acooling 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 withwhat 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 applicationand the selected end devices.
End device Any peripheral component which is being controlled by the thermostat: valves, damperactuators, relays, ect........
LED All thermostat have internal service LED & a system status Led on the cover. The internalservice LED are colored lights that can be viewed from the side of the thermostat they areenergized and the system status LED is the one mounted on the cover. ( See the checkout &start up procedures section )
Modulating analog2 to 10 Vdc outputT7984 series
A type of modulating signal that uses a variable DC voltage signal. This type of output on theT7984 series uses a half wave rectifier bridge. If the same transformer is to be used for thethermostat and the end device, be sure to select end devices which also use a half wave rectifierbridge.
Modulating tri-state floatingoutputT6984 series
A type of modulating signal that uses a set of 2 contacts, one to open the end device, the otherto close the end device. This type of output uses tri-state or floating type actuators. The actuatorwill open and close to multiple position according to demand. When the demand and thetemperature is satisfied, the thermostat will stop moving the actuator and will leave to its lastposition until the demand changes again.
Motor timingdefinition T6984and modulatingfloating outputonly
It is important when using T6984 and modulating floating actuator that motor timing dip switchsetting matches the actuator being used. The motor maximum timing is the maximum runningtime that the actuator may take to complete full stroke or maximum rotation. For optimumcontrol, select a dip switch timing setting which is equal or slightly shorter than the actualmaximum running time.( 20, 30, 60, 120, 150, 240, or 420 seconds )
Night setback,day-night modeor NSB
An energy saving mode by which the actual setpoints are modified to different value than theones 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 VABe 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 enddevices being controlled by the thermostat.
Power upsequence
Every time power is removed and reapplied to a thermostat, it will go through a power upsequence. This sequence resets all the function of the thermostat to the desired settings. ( Seethe 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. Ifa short occur, remove power to the thermostat for 30 seconds to reset the fuses. Remedyproblem 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: electricbase 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 thethermostat. On the T6984D & E & T7984A, B & C models, it is possible to install a remote roomor remote duct return sensor at a different location than the thermostat. The remote sensor arenot 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. Onthe 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 isthe 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 maximuminrush, 0.5A maximum running. When they are energized by the thermostat, their switchingaction is as follow:
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 thermostat3. 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
On thermostats which have output 1 cooling and output 2 heating ( T6984D, T7984B&C modelsonly ), the setpoint dial definition needs to be adjusted. ( See setpoint dial definition & setpointlimitation application note )These thermostats have 2 distinct setpoints, one for heating the other for cooling ( See thecontrol curves section ). When the room temperature is between those to setpoints both heatingand cooling outputs are not working, the room temperature is in the Zero energy band. When theroom temperature drops below the heating setpoint, output 2 output will energize. When theroom 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).
Output 2On/off
Motor open
Motor close
24 Vac
( 0 Vac )
Output 1
24 Vac valve or VAVfloating actuator
24 Vac on/offrelay or valve
24 Vac transformer
Common
OpenClose
R
Power supply
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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 ispossible to adjust the value of the zero energy band ( deadband ) using dip switch.
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T6984A
T6984E
Temperature increase
Cooling mode
Heating modechangeoverinput active
50 %
SETPOINT DIAL CENTERED
OUTPUT 1 FLOATING
Opened100%
Closed0%
Temperature increase
Cooling only mode
OUTPUT 1 FLOATING
50 %
Opened100%
Closed0%
SETPOINT DIAL CENTERED
Deviceopened
Deviceclosed
To use the thermostat ona heatingbonly application,
reverse the open/close wires
50 %
SETPOINT DIAL CENTERED
OUTPUT 1 FLOATING
Opened100%
Closed0%
Temperature increase
Heating only mode
Deviceopened
Deviceclosed
Deviceopened
Deviceclosed
Deviceopened
Deviceclosed
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Outout 1 floating in cooling modeOutput 2 on/off output in heating mode
50 %
SETPOINT DIAL DEFINITION
100%
0%
Temperature increase
Deviceopened
HEATINGSETPOINT
COOLINGSETPOINT
SETPOINTCENTERED
IN ZEROENERGY BAND
Deviceclosed
Deviceon
Deviceoff
ZERO ENERGY BAND
OUTPUT 1FLOATING
OUTPUT 2 ON/OFF
Mode A ( jumper not installed )
Output 1 floating in heating modeOutput 2 on/off output in cooling mode
50 %
SETPOINT DIAL DEFINITION
100%
0%
Temperature increase
Deviceopened
HEATINGSETPOINT
COOLINGSETPOINT
SETPOINTCENTERED
IN ZEROENERGY BAND
Deviceclosed
Deviceon
Deviceoff
ZERO ENERGY BAND
Mode B ( jumper installed )
OUTPUT 1FLOATING
OUTPUT 2 ON/OFF
T6984D
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T7984A
Temperature increase
Cooling mode
Heating modechangeoverinput active
OUTPUT 1 ANALOG
50 %
Opened100%
Closed0%
SETPOINT DIAL CENTERED
Deviceopened10 Vdc
Deviceclosed2 Vdc
Deviceopened10 Vdc
Deviceclosed2 Vdc
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Output 1 analog in cooling modeOutput 2 on/off in heating mode
50 %
SETPOINT DIAL DEFINITION
100%
0%
Temperature increase
Deviceopened10 vdc
HEATINGSETPOINT
COOLINGSETPOINT
SETPOINTCENTERED
IN ZEROENERGY BAND
Deviceclosed2 Vdc
Deviceon
Deviceoff
ZERO ENERGY BAND
OUTPUT 1ANALOG
OUTPUT 2 ON/OFF
Mode A ( jumper not installed )
Output 1 analog in heating modeOutput 2 on/off in cooling mode
50 %
SETPOINT DIAL DEFINITION
100%
0%
Temperature increase
Deviceopened10 Vdc
HEATINGSETPOINT
COOLINGSETPOINT
SETPOINTCENTERED
IN ZEROENERGY BAND
Deviceclosed2 Vdc
Deviceon
Deviceoff
ZERO ENERGY BAND
Mode B ( jumper installed )
OUTPUT 1ANALOG
OUTPUT 2 ON/OFF
T7984B
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Output 1 analog in cooling modeOutput 2 analog in heating mode
50 %
SETPOINT DIAL DEFINITION
100%
0%
Temperature increase
Deviceopened10 vdc
HEATINGSETPOINT
COOLINGSETPOINT
SETPOINTCENTERED
IN ZEROENERGY BAND
Deviceclosed2 Vdc
ZERO ENERGY BAND
OUTPUT 1ANALOG
OUTPUT 2 ANALOG
Changeover inputfor output 1 not active
Output 1 analog in heating modeOutput 2 analog in heating mode
50 %
SETPOINT DIAL DEFINITION
100%
0%
Temperature increase
Deviceopened10 Vdc
HEATINGSETPOINT
COOLINGSETPOINT
SETPOINTCENTERED
IN ZEROENERGY BAND
Deviceclosed2 Vdc
ZERO ENERGY BAND
OUTPUT 1ANALOG
OUTPUT 2ANALOG
T7984C
Deviceopened10 vdc
Deviceclosed2 Vdc
Deviceopened10 Vdc
Deviceclosed2 Vdc
Changeover inputfor output 1 activated
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3. Screw Terminals Arrangement
Internal sensor
Sensor input
Mode input
NSB input
Output 2On/off
Motor open
Motor close
24 Vac
Output 1
( 0 Vac )Power supply
Internal sensor
Sensor input
Changeoverinput for Out 1
Motor open
Motor close
24 Vac
Output 1
( 0 Vac )
( 0 Vac )Power supply
Motor open
Motor close
24 Vac
Output 1
( 0 Vac )Power supply
( 0 Vac )
T6984A
T6984D
T6984E
T6984 Series Thermostats
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Not used
Remotesensor input
Output 12-10 Vdc
( 0 Vac )
Changeoverinput for Out 1
Remotesensor input
Output 12-10 Vdc
Changeoverinput for Out 1
NSB input
Output 22-10 Vdc
Remotesensor input
Output 12-10 Vdc
Mode input
NSB input
Output 2On/off
24 Vac
( 0 Vac )Power supply
24 Vac( 0 Vac )
( 0 Vac )Power supply
24 Vac
( 0 Vac )Power supply
( 0 Vac )
T7984A
T7984B
T7984C
T7984 Series Thermostats
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4. Thermostat Dip Switch Definition
T6984 SeriesOUTPUT 2 ON/OFF CPH T6984D onlyFor more information, see on/off output cycle per hour application note.
CYCLES/HOUR S1FAST 8 CPH 1SLOW 4 CPH 0
It is possible to fix the number of time per hour the on/offoutput will be energized.
ZERO ENERGY BAND T6984D only
ZEB S25 °F ( 3 °C ) 1
3 °F ( 1.5 °C ) 0
On models which have 2 outputs, 1 for cooling and 1 forheating. It is possible to adjust the zero energy band value( dead band between heating and cooling setpoints )
SETPOINT DIAL DEFINITION T6984D onlyFor more information, see setpoint dial definition & setpoint limitation application note.
DEFINITION S3 S4 Models with cooling and heating outputs
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
MOTOR TIME T6984A, D & E
SECONDS S5 S6 S7420 1 1 1240 0 1 1150 1 0 1120 0 0 090 0 0 160 1 1 030 0 1 020 1 0 0
Motor timing dip switch setting must matchthe used actuator maximum running time.The motor maximum timing is themaximum running time that the actuatormay take to complete full stroke ormaximum rotation. For optimum control,select a dip switch timing setting which isequal or slightly shorter than the actualmaximum running time.
DAY/NIGHT SETBACK T6984D only
HEAT SETBACK COOL SETUP S810 °F ( 5 °C ) 20 °F (10 °C ) 15 °F ( 3 °C ) 5 °F ( 3 °C ) 0
Night mode setpoints can be adjustedto different values depending on theapplication.
SETPOINT DIAL DEFINITION
Temperature increase
Deviceopened
DAY HEATINGSETPOINT
DAY COOLINGSETPOINT
SETPOINTCENTERED
IN ZEROENERGY BAND
Deviceclosed
Deviceon
Deviceoff
ZERO ENERGY BAND
OUTPUT 1FLOATING
OUTPUT 2 ON/OFF
NIGHT HEATINGSETPOINT
NIGHT COOLINGSETPOINT
HEAT SETBACK COOL SETUP
DIP SWITCH ADJUSTMENTS FOR T6984D
1 2 3 4 5 6 7 8
ON = 1
OFF = 0
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T7984 SeriesOUTPUT 2 ON/OFF CPH T7984B onlyFor more information, see on/off output cycle per hour application note.
CYCLES/HOUR S1FAST 8 CPH 1SLOW 4 CPH 0
It is possible to fix the number of time per hour the on/offoutput will be energized.
ZERO ENERGY BAND T7984B & C only
ZEB S25 °F ( 3 °C ) 1
3 °F ( 1.5 °C ) 0
On models which have 2 outputs, 1 for cooling and 1 forheating. It is possible to adjust the zero energy band value( dead band between heating and cooling setpoints )
SETPOINT DIAL DEFINITION T7984B & C onlyFor more information, see setpoint dial definition & setpoint limitation application note.
DEFINITION S3 S4 Models with cooling and heating outputs
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
DAY/NIGHT SETBACK T7984B & C only
HEAT SETBACK COOL SETUP S510 °F ( 5 °C ) 20 °F (10 °C ) 15 °F ( 3 °C ) 5 °F ( 3 °C ) 0
Night mode setpoints can be adjustedto different values depending on theapplication.
REMOTE SENSOR T7984A, B & COn model T7984A, switch S7 & S8 are not used.
MAIN SENSOR S6LOCAL INTERNAL 1REMOTE SENSOR 0
For duct return air or remote room sensor control only. Donot use remote sensor in supply or discharge air controlapplications.
1 2 3 4 5 6
ON = 1
OFF = 0
SETPOINT DIAL DEFINITION
Temperature increase
Device100 %
DAY HEATINGSETPOINT
DAY COOLINGSETPOINT
SETPOINTCENTERED
IN ZEROENERGY BAND
Device0 %
Device100 %
Device0 %
ZERO ENERGY BAND
OUTPUT 1ANALOG
OUTPUT 2 ON/OFF OR ANALOG
NIGHT HEATINGSETPOINT
NIGHT COOLINGSETPOINT
HEAT SETBACK COOL SETUP
DIP SWITCH ADJUSTMENTS FOR T7984B & C
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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
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5.1. PI Control vs. On/Off Control
PI control stands for Proportional + Integral control. The T6984 & T7984 series thermostat useadvanced PI control algorithms with a small but powerful microcomputer built in the electroniccircuit board. These provide a precise temperature control and eliminate wasted heating or coolingenergy in conventional thermostats. As a result, the room occupant is able to adjust the desiredheating or cooling setpoint to is optimum comfort setting. The result is 5% to 10% energy savingwith improved comfort.
Comfort
Time
Temperature
Temperature
On/Off mechanical thermostats waste energy
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 10VDC 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 outputThe 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 windspeed, fuel used, engine temperature and efficiency, the gear that the transmission is in, theincline of the road, turbulence caused by traffic, number of passenger and total load, if the airconditioning is on or not, if the windows are open, the tires used and the tire pressure and probablya million other things !
You know that the cruise control will work adequately in a variety of situations, although sometimesresulting in very small control errors when things are changing ( under dynamic conditions ). If all isconstant 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 causethe 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 andmaintain setpoint more accurately.
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5.2. Modulating Floating Control T6984vs.
Analog 2 To 10 VDC Control T7984
Both T6984 & T7984 series thermostat use PI control and will fully modulate end devices. Bothtype of output are able to position the end device according to the actual demand from their PIcontrol 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 costthree point floating motorized valve and damper actuators.
Use analog 2 to 10 VDC control when Use floating control whenYou are controlling more than 1 valve or damper
actuatorYou are controlling only 1 valve or damper
actuatorWhen you are using spring return end devices When you are using end devices with no fail
safeWhen the total installed cost needs to be lower
When you are using large end devices When you are using small end devicesWhen you are less familiar with electronic
controls ( at first, they are easier to start-up andtroubleshoot )
When you are more familiar with electroniccontrols ***
*** It is important when starting-up and commissioning T6984 thermostats series that usesmodulating floating control to properly setup the actuator direction or rotation versus the thermostatopen/close direction of rotation.
Open contact on the thermostat Close contact on the thermostatNeeds to open the end device when activated 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 theactuator 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, onefor heating the other for cooling ( See the control curves section ). When the room temperature isbetween those to AM both heating and cooling outputs are not working, the room temperature is inthe Zero energy band. When the room temperature drops below the heating setpoint, the Reheatoutput will energize. When the room temperature rises above below the cooling setpoint, Stage 1will 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 energyband, 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.
50 %
SETPOINT DIAL DEFINED AS CENTERED
100%
0%
Deviceopened
TRUE HEATINGSETPOINT
TRUE COOLINGSETPOINT
DIALSETPOINTCENTEREDIN ZERO
ENERGY BAND
Deviceclosed
ZERO ENERGY BAND
STAGE 1REHEAT OUTPUT
Deviceoff
Deviceoff
50 %
SETPOINT DIAL DEFINED AS HEATING
100%
0%
Deviceopened
TRUE DIAL HEATINGSETPOINT
TRUE COOLINGSETPOINT
Deviceclosed
ZERO ENERGY BAND
STAGE 1REHEAT OUTPUT
Deviceoff
Deviceoff
50 %
SETPOINT DIAL DEFINED AS COOLING
100%
0%
Deviceopened
TRUE HEATINGSETPOINT
TRUE DIAL COOLINGSETPOINT
Deviceclosed
ZERO ENERGY BAND
STAGE 1REHEAT OUTPUT
Deviceoff
Deviceoff
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Setpoint limitation:
On thermostats which have Stage 1 ( cooling output ) and a Reheat output ( heating output ) Thesetpoints can be limited electronically. These thermostats have 2 distinct setpoints, one for heatingthe other for cooling.
These model only: T6984D & T7984B,C series thermostat feature a setpoint limitation which iscompatible with ASHRAE 90.1
Both setpoints are electronically limited to 75°F ( 24°C ). The cooling setpoint cannot belowered below 75°F and the heating setpoint cannot be raise above 75°F.
OUTPUT1
TRUE HEATINGSETPOINT
TRUE COOLINGSETPOINT
ZERO ENERGY BAND
OUTPUT 2
Device0 %
Device100%
TRUE HEATINGSETPOINT
TRUE COOLINGSETPOINT
ZERO ENERGY BAND
OUTPUT 1OUTPUT 2
SETPOINT DIAL TURNED TO ITS LOWEST VALUE
SETPOINT DIAL TURNED TO ITS HIGHEST VALUE
COOLING SETPOINT CANNOT BE LOWER
THAN 75F
HEATING SETPOINT CANNOT BE HIGHER
THAN 75F
HEATING CENTERED COOLING
HEATING CENTERED COOLING
MINIMUM COOLING SETPOINT
IS DIAL MAXIMUM SETTING
MINIMUM HEATING SETPOINT
IS DIAL MINIMUM SETTING
TRUE HEATING AND COOLING SETPOINTS ARE ELECTRONICALLYLIMITED AT 75F WHEN DIAL IS ROTATED LEFT TO RIGHT
Device0 %
Device100%
Device100%
Device0 %
Device0 %
Device100%
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This setpoint limitation can be overridden for system checkout by setting the dip switch to thefollowing: T6984D & T7984B,C set S=1 & S4=1. By doing this, the setpoint dial definition is nowcentered in the middle of the zero energy band.
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5.4. 4 To 20 ma. Output
Valid for these model only: T7984A1040, T7984B1048 & T7984C1046.
1. Wiring:
0 Vac common
4-20 mA output
using a 500 Ohms 1/4 watt 5% resistor
+
-
Shunt resistor value to convert 4 to 20 mA
back to a 2 to 10 Vdc control signal
+
-
4 to 20 mAdevice
+
-
OR
+
-
2 to 10 Vdc
2. Characteristics of 4 to 20 ma output is: maximum load 500 Ω at 20 ma. Voltage source is thenaround 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 orthe 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 outputcan be selected to work as the 4 to 20 mA output . Selection is done with dip switches.
Switch settings Output 1 Output 2 Dip switch #7 off Dip switch #8 off
Analog 2 to 10 VDC Analog 2 to 10 VDC
Dip switch #7 on Dip switch #8 off
4 to 20 mA Do not use and wire Stage 1 2 to 10 VDC screw terminal
Analog 2 to 10 VDC
Dip switch #7 off Dip switch #8 on
Analog 2 to 10 VDC 4 to 20 mA Do not use and wire Reheat stage
2 to 10 VDC screw terminal Dip switch #7 on Dip switch #8 on
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 mAoutput. Use either the selected 4 to 20 mA output or the 2 to 10 VDC output, but not both.
63-8592 22
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 whenmultiple 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 junctionscrew terminals than at the smaller ones on thethermostats.
• Looping the same power supply, NSB contact and/orchangeover contact from thermostat to thermostat is alot easier.
General wiring information:
• Always read the instruction manuals of all componentsinstalled in the system.
• Always make a wiring diagram of the installation you want to make before starting to wire thecomponents.
• 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 enddevices 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 10VDC end device it its controlling.
• It is important when starting-up and commissioning T6984 thermostats series that usesmodulating floating control to properly setup the actuator direction or rotation versus thethermostat open/close direction of rotation.
• For changeover application using sensors on T7984 models. 1 sensor per thermostat must beused.
24 Vac transformer
L
N
NSB contact
R
A
B
2 to 10 Vdc 24 Vac &NSB contact
to other thermostats
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24 Vac transformer
L
N
Honeywell
WIRING1 Feb 98 Rev.1
NSB contact
Changeover contact
24 Vac
Common
NSB input
Changeover input
24 Vac
Common
NSB input
Changeover input
24 Vac
Common
NSB input
Changeover input To other thermostats
Single transformer applicationA
B
Auxiliary screw terminals arrangementSingle transformer arrangement
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 recommendedwhen multiple wires are brought down at the thermostat. This maketroubleshooting, startup and servicing easier.
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Honeywell
WIRNG1 March 97 Rev.0
To other thermostats
24 Vac transformer 24 Vac transformer
LN
24 Vac transformer
LN
24 Vac
Common
NSB input
Changeover input
24 Vac
Common
NSB input
Changeover input
24 Vac
Common
NSB input
Changeover input
LN
AB AB AB
NSB contact
Changeover contact
Multiple transformer application
Auxiliary screw terminals arrangementMultiple transformer arrangement
For changeover application using sensors on T7984 models,1 sensor per thermostat must be used.
Only central NSB contact or changeover contact can be usedif 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.
25 63-8592
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. Thosesetting 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 8 cycles per hourAnything using a gas fired or oil fired terminalreheat device ( Never use 8 cycles per hour )
N.C. 24 Vac thermal valve( Hot wax thermal body valve )
Any gear driven end device valve or damperactuator
Properly sized electric base board strip Oversized capacity electric base board stripProperly sized electric duct heater Oversized capacity electric duct heater
If possible, always use the 4 cycles per hour setting. This setting increases the life span of the enddevice by lowering the number of annual cycles.
63-8592 26
27 63-8592
6. Application Drawings For Valves2 way and 3 way valves actuator
combinations for heating and/or coolingDrawingnumber
Valve: output 1modulating
floating control
Changeover ofvalve
(output 1) toheating mode
Output 2On/off
Nightsetback( NSB )
Optionnal remotesensor ( not forsupply controlapplications )
Thermostatmodel
number
T6984 THERMOSTAT SERIES: VALVE APPLICATIONSTO USE WITH VALVE ACTUATORS: VC6900 Series, VC6831 ( end switch model family ),
M6410, ML6161 & ML684
HWV100 Cooling orheating only
T6984A
HWV111 Cooling orheating only
X ( optionnal ) T6984E
HWV141 Cooling &heating →
Using a drycontact
X ( optionnal ) T6984E
HWV150 Cooling only On/off heatingonly
X X ( optionnal ) T6984D
HWV170 Heating only On/off coolingonly
X X ( optionnal ) T6984D
Drawingnumber
Valve: output 1Modulating 2 to10 Vdc control
Changeover ofvalve
( output 1 ) toheating mode
Output 2T7984Bon/off
T7984Canalog
Nightsetback( NSB )
Optionnal remotesensor ( not forsupply controlapplications )
Thermostatmodel
number
T7984 THERMOSTAT SERIES: VALVE APPLICATIONSTO USE WITH VALVE ACTUATORS: VC7900 Series, ML7984, M7410E & ML7161
HWV210 Cooling orheating only
X ( optionnal ) T7984A
HWV240 Cooling &heating →
Using a drycontact or
sensor
X ( optionnal ) T7984A
HWV250 Cooling only On/off heatingonly
X X ( optionnal ) T7984B
HWV270 Heating only On/off coolingonly
X X ( optionnal ) T7984B
HWV280 Cooling &heating →
Using a drycontact or
sensor
Analogheating only
X X ( optionnal ) T7984C
HWV282 Analog coolingonly
Analogheating only
X X ( optionnal ) T7984C
HWV284 Analog coolingonly
Analogheating only
X X ( optionnal ) T7984C
63-8592 28
24 Vac transformer
L
N
0 Vac
24 Vac
T6984A
HWV100 February 98 Rev.1
OpenOutput 1
Close
Floating valve actuator cooling
A
B
Sequence of operation for cooling:
Normal cooling mode, cold water supply
On a rise of temperature from setpoint1- Valve opens
On a drop of temperature from setpoint1- Valve closes
COOLING APPLICATION2 Way or 3 way valve
Modulating floatingvalve actuatorOpenCommon Close
For a heating only application:
Reverse open/close wires as shown
24 Vac
OpenOutput 1
Close
Common
Open
Close
29 63-8592
24 Vac transformer
L
N
0 Vac
24 Vac
T6984E
HWV111 February 98 Rev.1
OpenOutput 1
Close
Floating valve actuator cooling
A
B
Sequence of operation for cooling:
Normal cooling mode, cold water supply
On a rise of temperature from setpoint1- Valve opens
On a drop of temperature from setpoint1- Valve closes
COOLING APPLICATION2 Way or 3 way valve
Modulating floatingvalve actuatorOpenCommon Close
0 Vac
or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, leave factory wire jumper installedWhen remote sensor is used, remove factory wire jumperand connect sensor as shown
Sensor input
Internal sensor
Remove factorywire jumper
For a heating only application:
Install a jumper as shown
0 Vac
Changeoverinput for Out 1
63-8592 30
24 Vac transformer
L
N
0 Vac
24 Vac
T6984E
HWV141 February 98 Rev.1
OpenOutput 1
Close
Floating valve actuator coolingc/w heating changeover
A
B
COOLING & HEATING APPLICATIONc/w Changeover
2 Way or 3 way valve
Modulating floatingvalve actuatorOpenCommon Close
0 Vac
or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, leave factory wire jumper installedWhen remote sensor is used, remove factory wire jumperand connect sensor as shown
Sensor input
Internal sensor
Remove factorywire jumper
Sequence of operation:
Normal cooling mode, cold water supply
On a rise of temperature from setpoint1- Valve opens
On a drop of temperature from setpoint1- Valve closes
Changeover activatedHeating mode, hot water supply
On a rise of temperature from setpoint1- Valve closes
On a drop of temperature from setpoint1- Valve opens
Changeover contact
Changeoverinput for Out 1
31 63-8592
24 Vac transformer
L
N
0 Vac
24 Vac
T6984D
HWV150 February 98 Rev.1
OpenOutput 1
Close
A
B
Sequence of operation:
Normal cooling mode, cold water supply
On a rise of temperature from setpoint1- Valve opens
On a drop of temperature from setpoint1- Valve closes2- Reheat energizes
COOLING APPLICATION2 Way or 3 way valve
Modulating floatingvalve actuatorOpenCommon Close
0 Vac
or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, leave factory wire jumper installedWhen remote sensor is used, remove factory wire jumperand connect sensor as shown
Sensor input
Internal sensor
Remove factorywire jumper
Floating valve actuator coolingNight setback & on/off reheat
REHEAT OUTPUT DEVICES
R
R
Electric duct heater24 Vac relay without transformer
Perimeter hot water coil24 Vac 2 position N.C. valve
Hot water coil24 Vac 2 position N.C. valve
Electric base board24 Vac relay without transformer
NSB input
NSB contact
Output 2on/off
63-8592 32
24 Vac transformer
L
N
0 Vac
24 Vac
T6984D
HWV170 February 98 Rev.1
OpenOutput 1
Close
A
B
Sequence of operation:
On a rise of temperature from setpoint1- DX cooling stage starts
On a drop of temperature from setpoint1- Heating valve opens
HEATING2 Way or 3 way valve
Modulating floatingvalve actuatorOpenCommon Close
0 Vac
or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, leave factory wire jumper installedWhen remote sensor is used, remove factory wire jumperand connect sensor as shown
Sensor input
Internal sensor
Remove factorywire jumper
Floating valve actuator heatingNight setback & on/off cooling
NSB input
NSB contact
0 Vac
Mode input
Mode jumperinstalled
DX
COOLINGOn/off DX stage
Output 2on/off
24 Vacinterface
relayR
33 63-8592
24 Vac transformer
L
N
T7984A
HWV210 February 98 Rev.1
2 to 10 Vdc valve actuator cooling
A
B
Sequence of operation for cooling:
Normal cooling mode, cold water supply
On a rise of temperature from setpoint1- Valve opens
On a drop of temperature from setpoint1- Valve closes
COOLING APPLICATION2 Way or 3 way valve
Modulating 2 to 10 Vdcvalve actuator
For a heating only application:
Install a jumper as shown
0 Vac
Changeoverinput for Out 1
0 Vac or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, set dip switch #6 to position 1When remote sensor is used, set dip switch #6 to position 0
Remotesensor input
24 VacCommon Input2-10 Vdc
0 Vac
24 Vac
Output 12-10 Vdc
63-8592 34
T7984A
HWV240 February 98 Rev.1
2 to 10 Vdc valve actuator coolingc/w changeover
COOLING & HEATING APPLICATIONc/w Changeover
2 Way or 3 way valve
Changeoverinput for Out 1
0 Vac or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, set dip switch #6 to position 1When remote sensor is used, set dip switch #6 to position 0
Remotesensor input
Modulating 2 to 10 Vdcvalve actuator24 VacCommon Input
2-10 Vdc
0 Vac
24 Vac
Output 12-10 Vdc
Sequence of operation:
Normal cooling mode, cold water supply
On a rise of temperature from setpoint1- Valve opens
On a drop of temperature from setpoint1- Valve closes
Changeover activatedHeating mode, hot water supply
On a rise of temperature from setpoint1- Valve closes
On a drop of temperature from setpoint1- Valve opens
Changeover contactor
Changeover sensor
24 Vac transformer
L
N
A
B
35 63-8592
T7984B
HWV250 February 98 Rev.1
2 to 10 Vdc valve actuator coolingNight setback & on/off reheat
COOLING APPLICATION2 Way or 3 way valve
0 Vac or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, set dip switch #6 to position 1When remote sensor is used, set dip switch #6 to position 0
Remotesensor input
Modulating 2 to 10 Vdcvalve actuator24 VacCommon Input
2-10 Vdc
0 Vac
24 Vac
Output 12-10 Vdc
Sequence of operation:
Normal cooling mode, cold water supply
On a rise of temperature from setpoint1- Valve opens
On a drop of temperature from setpoint1- Valve closes2- Reheat energizes
24 Vac transformer
L
N
A
B
REHEAT OUTPUT DEVICES
Output 2on/off
NSB input
NSB contact
R
R
Electric duct heater24 Vac relay without transformer
Perimeter hot water coil24 Vac 2 position N.C. valve
Hot water coil24 Vac 2 position N.C. valve
Electric base board24 Vac relay without transformer
63-8592 36
T7984B
HWV270 February 98 Rev.1
2 to 10 Vdc valve actuator heatingNight setback & on/off cooling
HEATING2 Way or 3 way valve
0 Vac or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, set dip switch #6 to position 1When remote sensor is used, set dip switch #6 to position 0
Remotesensor input
Modulating 2 to 10 Vdcvalve actuator24 VacCommon Input
2-10 Vdc
24 Vac
Output 12-10 Vdc
24 Vac transformer
L
N
A
B
Output 2on/off
NSB input
NSB contact
Sequence of operation:
On a rise of temperature from setpoint1- DX cooling stage starts
On a drop of temperature from setpoint1- Heating valve opens
DX
COOLINGOn/off DX stage
24 Vacinterface
relayR
Mode input
Mode jumperinstalled
0 Vac
0 Vac
37 63-8592
T7984C
HWV280 February 98 Rev.1
2 to 10 Vdc valve actuator coolingc/w changeoverNight setback & modulating reheat
COOLING & HEATING APPLICATIONc/w Changeover
2 Way or 3 way valve
Changeoverinput for Out 1
0 Vac or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, set dip switch #6 to position 1When remote sensor is used, set dip switch #6 to position 0
Remotesensor input
Modulating 2 to 10 Vdcvalve actuator24 VacCommon Input
2-10 Vdc
0 Vac
24 Vac
Output 12-10 Vdc
Sequence of operation:
Normal cooling mode, cold water supply
On a rise of temperature from setpoint1- Valve opens
On a drop of temperature from setpoint1- Valve closes2- Reheat energizes
Changeover activatedHeating mode, hot water supply
On a rise of temperature from setpoint1- Valve closes
On a drop of temperature from setpoint1- Valve opens2- Reheat energizes
Changeover contactor
Changeover sensor
24 Vac transformer
L
N
A
B
REHEAT OUTPUT DEVICES
SCRPower Control
Electric base boardModulating 2 to 10 Vdc SCR
Perimeter hot water coilModulating 2 to 10 Vdc valve
Hot water coilModulating 2 to 10 Vdc valve
Output 22-10 Vdc
NSB input
NSB contact
63-8592 38
T7984C
HWV282 February 98 Rev.1
2 to 10 Vdc valve actuator coolingNight setback & modulating reheat
COOLING APPLICATION2 Way or 3 way valve
0 Vac or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, set dip switch #6 to position 1When remote sensor is used, set dip switch #6 to position 0
Remotesensor input
Modulating 2 to 10 Vdcvalve actuator24 VacCommon Input
2-10 Vdc
0 Vac
24 Vac
Output 12-10 Vdc
Sequence of operation:
Normal cooling mode, cold water supply
On a rise of temperature from setpoint1- Valve opens
On a drop of temperature from setpoint1- Valve closes2- Reheat energizes
24 Vac transformer
L
N
A
B
REHEAT OUTPUT DEVICES
SCRPower Control
Electric base boardModulating 2 to 10 Vdc SCR
Perimeter hot water coilModulating 2 to 10 Vdc valve
Hot water coilModulating 2 to 10 Vdc valve
Output 22-10 Vdc
NSB input
NSB contact
39 63-8592
T7984C
HWV284 February 98 Rev.1
2 to 10 Vdc valve actuator cooling2 to 10 Vdc valve actuator heatingNight setback
COOLING VALVE2 Way or 3 way valve
0 Vac or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, set dip switch #6 to position 1When remote sensor is used, set dip switch #6 to position 0
Remotesensor input
0 Vac
24 Vac
Output 12-10 Vdc
Sequence of operation:
Normal cooling mode, cold water supply
On a rise of temperature from setpoint1- Cooling valve opens
On a drop of temperature from setpoint1- Heating valve opens
24 Vac transformer
Output 22-10 Vdc
NSB input
NSB contact
HEATING VALVE2 Way or 3 way valve
A
B
L
N
Modulating 2 to 10 Vdcvalve actuator24 VacCommon Input
2-10 Vdc
Modulating 2 to 10 Vdcvalve actuator24 VacCommon Input
2-10 Vdc
63-8592 40
41 63-8592
7. Application Drawings For Boxes:
Zone dampers, By-pass, Pressure dependent VAV & MechanicallyCompensated VAV
Drawingnumber
Box: output 1modulating
floating control
Changeover ofBox
( output 1 ) toheating mode
Output 2On/off
Nightsetback( NSB )
Optionalremote
sensor ( notfor supply
controlapplications )
Thermostatmodel
number
T6984 THERMOSTAT SERIES: ZONE DAMPER APPLICATIONSTO USE WITH VAV ACTUATORS: ML6161
HWB100 Cooling only T6984AHWB111 Cooling only X ( optional ) T6984EHWB141 Cooling & heating
→Using a dry
contactX ( optional ) T6984E
HWB172 Cooling only Heating only X X ( optional ) T6984D
Drawingnumber
Box: output 1Modulating 2 to10 Vdc control
Changeover ofbox
( output 1 ) toheating mode
Output 2T7984B on/offT7984C analog
Nightsetback( NSB )
Optionalremote
sensor ( notfor supply
controlapplications )
Thermostatmodel
number
T7984 THERMOSTAT SERIES: ZONE DAMPER APPLICATIONSTO USE WITH VAV ACTUATORS: ML7161
HWB210 Cooling only X ( optional ) T7984AHWB240 Cooling & heating
→Using a dry
contact or sensorX ( optional ) T7984A
HWB272 Cooling only On/off heatingonly
X X ( optional ) T7984B
HWB282 Cooling only Analog heatingonly
X X ( optional ) T7984C
HWB280 Cooling & heating→
Using a drycontact or sensor
Analog heatingonly
X X ( optional ) T7984C
63-8592 42
24 Vac transformer
L
N
0 Vac
24 Vac
T6984A
HWB100 February 98 Rev.1
OpenOutput 1
Close
Floating actuator cooling
A
B
Sequence of operation:
Normal cooling mode, cold air supply
On a rise of temperature from setpoint1- Box opens
On a drop of temperature from setpoint1- Box closes
COOLING APPLICATIONZone damper
Modulating floatingVAV actuatorOpenCommon Close
43 63-8592
24 Vac transformer
L
N
0 Vac
24 Vac
T6984E
HWB111 February 98 Rev.1
OpenOutput 1
Close
Floating actuator cooling
A
B
Sequence of operation:
Normal cooling mode, cold air supply
On a rise of temperature from setpoint1- Box opens
On a drop of temperature from setpoint1- Box closes
COOLING APPLICATIONZone damper
Modulating floatingVAV actuator
0 Vac
or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, leave factory wire jumper installedWhen remote sensor is used, remove factory wire jumperand connect sensor as shown
Sensor input
OpenCommon Close
Internal sensor
Remove factorywire jumper
factory wire jumper installed
63-8592 44
24 Vac transformer
L
N
0 Vac
24 Vac
T6984E
HWB141 February 98 Rev.1
OpenOutput 1
Close
Floating actuator coolingc/w changeover
Modulating floatingVAV actuator
0 Vac
or
Remote room or remote duct return sensor
Sensor input
OpenCommon Close
Internal sensor
Remove factorywire jumper
Sequence of operation:
Normal cooling mode, cold air supply
On a rise of temperature from setpoint1- Box opens
On a drop of temperature from setpoint1- Box closes
Changeover activatedHeating mode, hot air supply
On a rise of temperature from setpoint1- Box closes
On a drop of temperature from setpoint1- Box opens
COOLING & HEATING APPLICATIONc/w Changeover Zone damper
Changeover contact
Changeoverinput for Out 1
A
B
Important: Not for duct supply control applications
Important:When remote sensor is not used, leave factory wire jumper installedWhen remote sensor is used, remove factory wire jumperand connect sensor as shown
45 63-8592
24 Vac transformer
L
N
0 Vac
24 Vac
T6984D
HWB172 February 98 Rev.1
OpenOutput 1
Close
Floating actuator coolingNight setback & on/off reheat
A
B
NSB input
NSB contact
REHEAT OUTPUT DEVICES
Output 2on/off
Sequence of operation:
Normal cooling mode, cold air supply
On a rise of temperature from setpoint1- Box opens
On a drop of temperature from setpoint1- Box closes2- Reheat energizes
COOLING APPLICATIONZone damper
Modulating floatingVAV actuator
R
R
Electric duct heater24 Vac relay without transformer
Perimeter hot water coil24 Vac 2 position N.C. valve
Hot water coil24 Vac 2 position N.C. valve
Electric base board24 Vac relay without transformer
0 Vac
or
Remote room or remote duct return sensor
Sensor input
OpenCommon Close
Internal sensor
Remove factorywire jumper
Important: Not for duct supply control applications
Important:When remote sensor is not used, leave factory wire jumper installedWhen remote sensor is used, remove factory wire jumperand connect sensor as shown
63-8592 46
24 Vac transformer
L
N
0 Vac
24 Vac
T7984A
HWB210 February 98 Rev.1
Output 12-10 Vdc
Analog 2-10 Vdc actuator cooling
A
B
Sequence of operation:
Normal cooling mode, cold air supply
On a rise of temperature from setpoint1- Box opens
On a drop of temperature from setpoint1- Box closes
COOLING APPLICATIONZone damper
Modulating 2 to 10 VdcVAV actuator24 VacCommon Input
2-10 Vdc
0 Vac or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, set dip switch #6 to position 1When remote sensor is used, set dip switch #6 to position 0
Remotesensor input
47 63-8592
24 Vac transformer
L
N
0 Vac
24 Vac
T7984A
HWB240 February 98 Rev.1
Output 12-10 Vdc
Analog 2-10 Vdc actuator coolingc/w changeover
A
B
Sequence of operation:
Normal cooling mode, cold air supply
On a rise of temperature from setpoint1- Box opens
On a drop of temperature from setpoint1- Box closes
Changeover activatedHeating mode, hot air supply
On a rise of temperature from setpoint1- Box closes
On a drop of temperature from setpoint1- Box opens
COOLING & HEATING APPLICATIONc/w Changeover Zone damper
Modulating 2 to 10 VdcVAV actuator24 VacCommon Input
2-10 Vdc
Changeover contactor
Changeover sensor
Changeoverinput for Out 1
0 Vac or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, set dip switch #6 to position 1When remote sensor is used, set dip switch #6 to position 0
Remotesensor input
63-8592 48
24 Vac transformer
L
N
0 Vac
24 Vac
T7984B
HWB272 February 98 Rev.1
Output 12-10 Vdc
Analog 2-10 Vdc actuator coolingNight setback & on/off reheat
A
B
NSB input
NSB contact
REHEAT OUTPUT DEVICES
Output 2on/off
Sequence of operation:
Normal cooling mode, cold air supply
On a rise of temperature from setpoint1- Box opens
On a drop of temperature from setpoint1- Box closes2- Reheat energizes
COOLING APPLICATIONZone damper
Modulating 2 to 10 VdcVAV actuator24 VacCommon Input
2-10 Vdc
R
R
Electric duct heater24 Vac relay without transformer
Perimeter hot water coil24 Vac 2 position N.C. valve
Hot water coil24 Vac 2 position N.C. valve
Electric base board24 Vac relay without transformer
0 Vac or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, set dip switch #6 to position 1When remote sensor is used, set dip switch #6 to position 0
Remotesensor input
49 63-8592
24 Vac transformer
L
N
0 Vac
24 Vac
T7984C
HWB280 February 98 Rev.1
Output 12-10 Vdc
Analog 2-10 Vdc actuator coolingc/w changeoverNight setback & modulating reheat
A
B
NSB input
REHEAT OUTPUT DEVICES
SCRPower Control
Electric base boardModulating 2 to 10 Vdc SCR
Perimeter hot water coilModulating 2 to 10 Vdc valve
Hot water coilModulating 2 to 10 Vdc valve
Output 22-10 Vdc
Sequence of operation:
Normal cooling mode, cold air supply
On a rise of temperature from setpoint1- Box opens
On a drop of temperature from setpoint1- Box closes2- Reheat energizes
Changeover activatedHeating mode, hot air supply
On a rise of temperature from setpoint1- Box closes
On a drop of temperature from setpoint1- Box opens2- Reheat energizes
COOLING & HEATING APPLICATIONc/w Changeover Zone damper
Modulating 2 to 10 VdcVAV actuator24 VacCommon Input
2-10 Vdc
NSB contactChangeover contact
orChangeover sensor
Changeoverinput for Out 1
0 Vac or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, set dip switch #6 to position 1When remote sensor is used, set dip switch #6 to position 0
Remotesensor input
63-8592 50
24 Vac transformer
L
N
0 Vac
24 Vac
T7984C
HWB282 February 98 Rev.1
Output 12-10 Vdc
Analog 2-10 Vdc actuator coolingNight setback & modulating reheat
A
B
NSB input
NSB contact
REHEAT OUTPUT DEVICES
SCRPower Control
Electric base boardModulating 2 to 10 Vdc SCR
Perimeter hot water coilModulating 2 to 10 Vdc valve
Hot water coilModulating 2 to 10 Vdc valve
Output 22-10 Vdc
Sequence of operation:
Normal cooling mode, cold air supply
On a rise of temperature from setpoint1- Box opens
On a drop of temperature from setpoint1- Box closes2- Reheat energizes
COOLING APPLICATIONZone damper
Modulating 2 to 10 VdcVAV actuator24 VacCommon Input
2-10 Vdc
0 Vac or
Remote room or remote duct return sensor
Important: Not for duct supply control applications
Important:When remote sensor is not used, set dip switch #6 to position 1When remote sensor is used, set dip switch #6 to position 0
Remotesensor input
51 63-8592
8. Checkout & Start Up Procedures
Electronic thermostats require special care for wiring and startup. To avoid problems, carefully follow theenclosed 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 towork.
Make the wiring according to the wiring diagrams. Respect polarity for 24 Vac power terminals between multiplethermostats 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 thethermostat 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 maximumrunning. Do not go above the triacs rating.
When they are energized by the thermostat, their switching action is as follow:
24 Vac transformer0 Vac Common
24 Vac
Motor close
Motor open T6984
L
N
A
ActuatorCommon
Close
Open
B
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 thermostat3. 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.
63-8592 52
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 maximumrunning. Do not go above the triacs rating.
When they are energized by the thermostat, their switching action is as follow:
24 Vac transformer0 Vac Common
24 Vac
Reheat
L
N
A
24 Vac reheat device
B
R1. 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 setpointdemand for X minutes. X being the maximum selected running time dip switch setting of the floating actuator. Themicro-processor is making sure that the actuator is fully closed before taking control. So for X minutes after poweringup the thermostat the actuator will not respond to a setpoint change.
53 63-8592
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 modeRotate setpoint dial to: Output 1 actuator Output 1 internal LED Output 2:
if usedOutput 2 internal LED
Minimum position Opening Green on (opening) Not energized Red ( Off )
Maximum position Closing Yellow on (closing) Energized Red ( On )
T6984 Actuator ( output 1 ) in heating modeInstall a jumper across the Common and changeover screw terminals
Rotate setpoint dial to: Output 1 actuator Output 1 internal LED Output 2:if used
Output 2 internal LED
Minimum position Closing Yellow on (closing) Not energized Red ( Off )
Maximum position Opening Green on (opening) Energized Red ( On )
T7984 Actuator ( output 1 ) in cooling modeRotate setpoint dial to: Output 1 actuator Output 1 internal LED Output 2:
if usedOutput 2 internal LED
Minimum position Opening Green on (opening) Not energized Red ( Off )
Maximum position Closing Green off (closing) Energized Red ( On )
T7984 Actuator ( output 1 ) in heating modeInstall a jumper across the Common and changeover screw terminals
Rotate setpoint dial to: Output 1 actuator Output 1 internal LED Output 2:if used
Output 2 internal LED
Minimum position Closing Green off (closing) Not energized Red ( Off )
Maximum position Opening Green on (opening) Energized Red ( On )
When done, connect back all wires and reset setpoint dial definition dip switch to their intended value.
63-8592 54
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