PECO T8168B-2 BACnet Proportional Thermostat Installation Guide

PECO T8168B-2 BACnet Proportional Thermostat

Product Information

Specifications

• Input Power: 24 VAC (20-30 VAC) 50/60 Hz (+/- 10%)
• Terminal Connections: 14-24 AWG stranded or solid wire
• Operating Humidity: 5% to 95% RH, non-condensing
• Physical Dimensions: 4.3 H x 5.7 W x 1.3D
• Proportional Stroke Time Default: 2 Minutes (Configurable)

Product Usage Instructions

Part I: Install Wall Plate

1. Position the wall plate on the wall with the directional arrow pointing up and terminal blocks facing outward.
2. Pull equipment wires through the wall plate wiring passage.
3. Use a level to determine the best horizontal wall plate mounting position.
4. Mark positions of screw holes with a pencil and remove wall plate.
5. Drill holes at marked locations (3/16 for drywall, 7/32 for plaster).
6. Insert wall anchors in the holes and mount the wall plate onto the wall.
7. Cap off any unused wires and terminate properly according to local building codes.

Part II: Attach Wires to Thermostat Wall Plate

1. Select terminal designations that correspond to the system type.
2. Loosen screws on terminal blocks and insert wires into appropriate terminal blocks.
3. Assure no uninsulated wires are exposed and cap off any unused wires.

Part III: Connect Power to the Thermostat Wall Plate

1. The T8168 operates on 24VAC power.
2. Refer to Terminal Block Designations for connection of 24 VAC.
3. Wait at least one hour for the displayed temperature to stabilize.

Frequently Asked Questions

Q: What is the recommended height for thermostat installation?

A: Locate the thermostat about four feet (1.2m) above the floor on a wall with good ventilation, average temperature, and good response to temperature changes.

Q: What are the load requirements for the different outputs?

A: Outputs Y1, Y2, W1, W2, G, G1 require 24 VAC (20-30 VAC) and a load must be connected for testing. Outputs WD, GD, YD have specific load requirements based on voltage or current output.

Q: How does the thermostat achieve accuracy and quiet operation?

A: This thermostat uses triacs switching for accuracy and quiet operation.

The PECO BACnet® T8168B-2 thermostat
Thank you for choosing a PECO® Performance PRO™ thermostat. The T8168B-2 thermostat is intended for commercial and residential enviroments. It supports both programmable and non-programmable operation.
Key features include: Either BACnet® IP or MS/TP Connectivity, auto- changeover; optional remote sensor; three levels of keypad lockout with optional PIN access code; a heat/cool Demand Indicator; up to four scheduled events per day, a 365-day calendar, 20 holidays, holiday override and temporary override.

Applications

The PECO® Performance PRO™ T8168 applications include fan coil, PTAC and conventional system with a single, multi speed or 0-10 VDC Fan.

• System Mode Selections: Off-Heat-Cool-Auto
• ON-OFF Heat/Cool Outputs: Up to 2 Heat, 2 Cool
• Proportional Heat/Cool Outputs: Three Wire Floating or 0-10 VDC Control
• Fan Control: Cycling (Auto) or Continuous (On); Up to 3 Speeds or Staged Permanent Memory: All device settings are stored in permanent memory.
• Optional Connections: Remote Sensor, Pipe Sensor, Fault Detection and Setback

CAUTION!

• 24 VAC low-voltage thermostat. Do not install on voltages higher than 30 VAC.
• Use copper wire only
• Use care to avoid electrostatic discharge to the thermostat.

Note: A load must be connected to outputs for testing

RATINGS

Outputs: Y1, Y2, W1, W2, G, G1 24 VAC (20-30 VAC); 50/60 Hz 10 VA
Outputs: WD, GD, YD 0-10 VDC: Loads must be 1.2K ohms minimum 4-20 mA: Loads must be 600 ohms maximum
This thermostat uses triacs switching for accuracy and quiet operation.

INSTALLATION INSTRUCTIONS

Select an appropriate thermostat location
Locate the thermostat about four feet (1.2m) above the floor on a wall with good ventilation, average temperature and good response to temperature changes. The T8168 may be mounted on a:

• Horizontal or vertical 2” X 4” device box
• Horizontal 4” X 4” device box
• Flat surface

Do not locate the thermostat where it can be affected by:

• Direct sunlight
• Drafts or dead areas behind doors
• Radiating heat or cool from appliances or equipment
• Concealed pipes or chimneys
• Outside walls or unheated/uncooled areas

Required components (not included, unless otherwise specified):

• Screws and wall anchors (included)
• Screwdrivers: Phillips (for wallplate); small flathead (for terminal blocks)
• Drill with 3/16” drill bit (or 7/32” for plaster)
• Wire cutter and stripper
• Level

WARNING

• READ THESE INSTRUCTIONS CAREFULLY BEFORE ATTEMPTING TO INSTALL, OPERATE OR SERVICE THIS THERMOSTAT.
• Failure to observe safety information and comply with instructions could result in PERSONAL INJURY, DEATH AND/OR PROPERTY DAMAGE.
• To avoid electrical shock or damage to equipment, disconnect power before installing or servicing and use only wiring with insulation rated for full thermostat operating voltage.
• Use care to avoid electrostatic discharge.
• To avoid potential fire and/or explosion do not use in potentially flammable or explosive atmospheres.
• Retain these instructions for future reference.
• This product, when installed, will be part of an engineered system whose specifications and performance characteristics are not designed or controlled by PECO® . Review applications and national and local codes to assure that the installation will be functional and safe.

TERMINAL BLOCK DESIGNATIONS

WARNING: Disconnect power before beginning installation.

• CAUTION: Use copper wire only
• CAUTION: Do not connect unused wires together

TECHNICAL SPECIFICATIONS

• Temperature Control Range: 50° to 90° F (10° to 32° C)
• Differential: 1° F (0.5°C)
• Input Power: 24 VAC (20-30 VAC) 50/60 Hz (+/- 10%)
• Terminal Connections: 14-24 AWG stranded or solid wire
• Operating Temperature: 0° to 120°F (-18° to 49°C)
• Shipping/Storage Temperature: -20° to 130°F (-29° to 54°C)
• Operating Humidity: 5% to 95% RH, non-condensing
• Physical Dimensions: 4.3” H x 5.7” W x 1.3”D
• Proportional Output Band Width: 2°F (1°C)
• Proportional Stroke Time Default: 2 Minutes (Configurable)

PART I: INSTALL WALL PLATE

1. Position the wall plate on the wall with the directional arrow pointing up and terminal blocks facing outward.
2. Pull equipment wires through the wall plate wiring passage.
3. Use a level to determine the best horizontal wall plate mounting position.
4. Mark positions of screw holes (two) with a pencil and remove wall plate.
5. Drill holes at pencil-marked locations (3/16” for drywall, 7/32” for plaster).
6. Insert the wall anchors in the holes, tapping them into place.
7. Mount the wall plate onto the wall and insert screws through mounting holes. Assure that all loose wires come through the center opening of the wall plate. Note: Do not over-tighten screws or use excessive force. This can cause the wall plate to warp and may cause intermittent connections between the base and the thermostat.
8. Cap off any unused wires and terminate properly according to local building codes.

PART II: ATTACH WIRES TO THERMOSTAT WALL PLATE

1. Select the terminal designations that correspond to the system type.
2. Using a small flathead screwdriver, loosen the screws on the terminal blocks, Strip the insulation of each wire at a proper length (about 1/4” or 64 cm) and insert wires into the terminal blocks.
3. Assure that no uninsulated wires are exposed: Cap off and place a wire-nut on any unused wires. Assure that the attached wires fit into the cavity on the back side of the thermostat.

PART III: CONNECT POWER TO THE THERMOSTAT WALL PLATE

1. The T8168 operates on 24VAC power.
2. See Terminal Block Designations on page 1 for connection of 24 VAC
3. Typical wiring diagrams are in the back for reference.
   NOTE: Wait at least one hour for the displayed temperature to stabalize.

PART IV: MOUNT THE T8168 ONTO THE WALL PLATE

1. Position the thermostat slightly above the mounted wall plate, then secure the hooks on the back side of the thermostat to the hinge pockets on the wall plate. Note: The top back side of the thermostat should slip into the hinge pockets easily. Do not use excessive force.
2. Align the pins on the back side of the thermostat with the terminal blocks on the wall plate.
3. Gently bring down the thermostat onto the wall plate so the pins on the back of the thermostat fit into the terminal blocks on the wall plate.
4. Attach the retaining screw to the underside of the thermostat as shown.

PART V: SET CLOCK, MONTH, AND DAY
When power is first applied to the thermostat, it will activate the clock display. It is recommended that time and day are entered before performing advanced configuration. Setting the clock can also be accessed by selecting MORE then CLOCK. Set clock as follows:

• ▲/ ▼= Arrows set selection. Note: The flashing option is the default selection.
• NEXT = Advances to next menu.
• Menu selections are: 12 to 24 hour format – Hour – Minutes – Year – Month – Day
• DONE = Press Done when operation is complete.
  NOTE: Display of Clock is not available when configured for non-programmable operation.

PART VI: VERIFY THERMOSTAT OPERATION WITH SYSTEM TESTS
System test verification is highly recommended to verify thermostat operation. For all system tests, press Next to continue to the following system test, or next available Service Menu. Press Done only if finished performing all system tests. Pressing Done exits the Service Menus and turns off all active outputs. See Service Menus: 600, 610, 620.

PART VII: REMOVE BATTERY INSULATOR TAB

SYSTEM TYPE: Service Menu 110 Output Configuration

1 Heat

1 Cool

1 Fan

| 2 Heat

1 Cool

1 Fan

| 1 Heat

1 Cool

3 Fan

| 2 Heat

1 Cool

3 Fan

| 2 Heat

2 Cool

2 Fan

| Heat Only 1 Fan| Cool Only 1 Fan| Heat Only 2 Fan| Cool Only 2 Fan| Heat Only 3 Fan| Cool Only 3 Fan| Heat TWF 1 Cool

2 Fan

| TWF Heat 1 Cool

3 Fan

| TWF Cool 1 Heat

2 Fan

| TWF Heat TWF Cool 2 Fan| 0-10

VDC

Only

ON-OFF Outputs

| Y1| Cool 1| Cool 1| Cool 1| Cool 1| Cool 1| –| Cool 1| –| Cool 1| –| Cool 1| Cool 1| Cool 1| Cool Open| Cool Open| –
W1| Heat 1| Heat 1| Heat 1| Heat 1| Heat 1| Heat 1| –| Heat 1| –| Heat 1| –| Heat Open| Heat Open| Heat 1| Heat Open| –
Y2| –| –| FAN MED| FAN MED| COOL 2| –| Cool 2| –| Cool 2| FAN MED| FAN MED| Cool2| FAN MED| Cool Close| Cool Close| –
W2| –| Heat 2| –| Heat 2| Heat 2| Heat 2| –| Heat 2| –| Heat 2| –| Heat Close| Heat Close| Heat 2| Heat Close| –
G| FAN| FAN| FAN HI| FAN HI| FAN HI| FAN| FAN| FAN HI| FAN HI| FAN HI| FAN HI| FAN HI| FAN HI| FAN HI| FAN HI| –
G1| Damper| Damper| FAN LO| FAN LO| FAN LO| Damper| Damper| FAN LO| FAN LO| FAN LO| FAN LO| FAN LO| FAN LO| FAN LO| FAN LO| Damper
0-10

VDC

| YD| Cool 1| Cool 1| Cool 1| Cool 1| Cool 1| –| Cool 1| –| Cool 1| –| Cool 1| Cool 1| Cool 1| Cool 1| Cool 1| Cool 1
WD| Heat 1| Heat 1| Heat 1| Heat 1| Heat 1| Heat 1| –| Heat 1| –| Heat 1| –| Heat 1| Heat 1| Heat 1| Heat 1| Heat 1

• When System Fan Type (SM112) is set to 1 or 2 (0-10 VDC operation), the GD output is the only fan oputput and G1 provides Damper operation.
• When Fan Coil 2-Pipe operation is selected the W1 and WD outputs will be disabled. See SM 171.

THERMOSTAT PROGRAMMING

This thermostat is easily changed from non-programmable to programmable operation in Service Menu 100. See the Operating Maunal for detailed instructions on setting up schedules. In non-programmable mode the thermostat controls to a single setpoint with the dead-band used for auto changeover from Heat to Cool.

OUTPUT OPERATION

The T8168 uses System Types for control of 24 VAC ON-OFF fans and relays; three wire floating and proportional 0-10 VDC fans, valves and dampers.

• ON-OFF outputs have a 1°F Differential.
• Proportional outputs use a Proportional Integral Algorithm to modulate the position of the actuator over 2°F.
• Three Wire Floating outputs have an adjustable stroke time that is set in Service Menu 114. The default is 2 minutes.
• When using Three Wire Floation (TWF) System Types wait 3 times the value set for Valve Stroke Time, set in SM 114, for normal operation to begin.

FAN AND DAMPER OPERATION

The T8168 offers either ON-OFF or 0-10 VDC fan operation, as follows:
ON/OFF FAN Operation (Service Menu 112 Selection 0)
The thermostat will provide up to 3 fan speeds. In this operation there is no proportional fan output, terminal GD is disabled. Selectable fan speeds are controlled by Service Menu 110.
0-10 VDC FAN HI-MED-LOW Operation (Service Menu 112 Selection 1) User selection of 0-10 VDC (or 4-20mA) fan speed is as follows:

• HI – Set in SM 125 for heating and SM 126 for cooling.
• MED – Controls at the midpoint between the HI and LO settings.
• LO – Set in SM 127.
  A delay of fan speed transition after adjustment can be set in SM 113.

Proportional 0-10 VDC Operation (Service Menu 112 Selection 2)
The 0-10 VDC fan will range between MAX and MIN Voltages (SM 125,126,127) based on the PI algorithm, the active demand and selected limits. Display of HI-MED-LO is suppressed. User selection is limited to FAN ON or FAN AUTO, depending on configuration.

Damper Operation (Service Menu 111)
A damper output is available when terminal G1 is not being used as a fan speed. Cycled vs continuous operation is determined in SM 111.

Staged Fan Operation (Service Menu 350)
Available for multi-fan and 0-10 VDC fan operation. When active, the user does not have access to fan speed.

Programmable Fan Operation (Service Menu 500)
This feature changes the fan operation to ON (continuous) during scheduled Occupied events. TIP: Disable Fan ON selection in SM 350 to ensure cycled operation in unoccupied scheduled events.

Intermittent Fan Operation (Service Menus 500, 501, 502)
Provides minimum timed fan operation by cycling the fan on and off.

KEYPAD LOCK OUT
The keypad lockout function blocks access to features by hiding them from the user’s view/selectability. Service Menu 340 has 3 levels of lock out. If a PIN is used to enter the Service Menu, all key pad lockouts will be disabled for a period of five minutes.

SETBACK
An occupancy sensor can be used between S1 & SC terminals to change the thermostat control points to Setback Low (SM 310) and Setback High (SM 320). A contact closure is used to signal a Setback requirement. In Setback the fan will cycle on at the lowest available speed. This feature is not available when using a remote sensor.

FAN COIL 2-PIPE/ 4-PIPE OPERATION
Service Menu 171 sets 2-pipe or 4-pipe fan coil operation.

2-Pipe Operation

2-Pipe Operation| Summer

(Cold Water or Open Input)

| Winter

(Hot Water or Closed Input)

---|---|---
Stage 1 Cool Y1 & YD| Cool| Heat
Stage 1 Heat W1 & WD| Disabled| Disabled

2-pipe operation disables W1 and WD outputs. Y1 and YD are used for first stage of cool in summer and first stage of heat in winter.

4-Pipe Operation| Summer

(Cold Water or Open Input)

| Winter

(Hot Water or Closed Input)

---|---|---
Stage 1 Cool Y1 & YD| Cool| Heat
Stage 1 Heat W1 & WD| Heat| Disabled

4-pipe operation uses both first stage Cool (Y1 & YD) and first stage Heat (W1 & WD) when chilled water (Summer) is available. When hot water (Winter) is available W1 and WD outputs are disabled and Y1 and YD are used for first stage of heating. Second stages are available, depending on system type.

PIPE SENSOR: SEASONAL CHANGE OVER
This feature is enabled when 2-pipe or 4-pipe operation is selected in Service Menu 171. With a pipe sensor connected to the T8168, the system will automatically change from Summer (cold water) to Winter (hot water) operation based on water temperature in the main piping riser. This input is looking for a valid temperature reading when using a pipe sensor, or a contact open/close if using an aqua-stat.

• Summer operation is enabled if the input is open or if the sensed temperature is below the threshold selection in SM 172.
• Winter operation is enabled if the input is closed or if the sensed temperature is above the threshold selection in SM 173.

If the water temperature sensed is between selections in SM 172 and SM 173 the water temperature is considered Ambiguous. The Y1 and YD outputs will be turned on for 3-minutes. After the 3 minute purge cycle, the thermostat checks again to see if the water temperature is Summer or Winter. If yes, the thermostat will transition to normal operation. If no, the operation is base on selection at Service Menu 174.
NOTE: If at any time the demand goes away, the thermostat will abort the purge cycle.

SYSTEM FLUSH FOR FAN COIL VALVES
Enable a periodic opening of valve(s) to flush valves and reduce sediment buildup using Service Menus 375, 376 and 377.

ACCESSORY SENSOR CONNECTIONS
S1 Input: connect optional remotes sensing, occupancy detection, door open or fault notification.

• For Remote Probe use, including sensor averaging between the onboard sensor and the remote sensor, see SM 170.
• For occupancy, door open or fault notification see SM 175

S2 Input: uses a a PECO pipe sensor or dry switch aqua-stat for use on fan coil seasonal change over.

ADVANCED CONFIGURATION SERVICE MENUS

CONFIGURE SERVICE MENUS
The following Service Menus (SM) commonly require configuration. Please verify that these are set for your specific application. Additional configuration may be required.

• SM 100 = Programmable or Nonprogrammable
• SM 110 = System Type
• SM 112 = Fan Type
• SM 135 = W1 Heat Output NO or NC
• SM 170 = Remote Sensors
• SM 240 = Number of Programmable Events per Day
• SM 395 = Override Duration for Programmable Operation
• SM 340 = Keypad Lock Out

SERVICE MENU ACCESS

1. Hold lower right and lower left keys for five seconds.
2. Press Next or Go Back button to select a Service Menu.
3. Press ▲/ ▼ to select option.
4. Press Done when complete.

format. In non-programmable mode all scheduling functions are removed from the display.
1 = Programmable
2 = 5-1-1 Schedule Mode
3 = 5-2 Schedule Mode
101| Daylight Savings| 0 = Disabled (Default)| When enabled daylight savings time follows the US 2007 format. (Begins second Sunday of March at 2AM and ends on the first Sunday of November at 2AM.
1 = Enabled (2007 US Format)
110| System Type| 1| 1 Stage Heat /1 Stage Cool Fan: Single Speed| System Type Notes

•  Fan can be changed from ON/OFF to 0-10 VDC Operation.

•  Stage 1 operation includes Y1/ W1 and 0-10 VDC outputs YD./ WD

•  System types may disable some service menu unavailablity

•  TWF = Three Wire Floating (valve)

__

Typical System Configuations:

2-Pipe Fan Coil with Electric Heat

•  Connect the Valve to Stage 1 Cool and the Heat Relay to Stage 1 Heat

•  SM110=01,02,03,04,05 or 14

•  SM171=02 (4-Pipe Operation)

•  When using a pipe sensor, Operation of Cool Stage 1 will change. In winter, heating will be provided from the valve (Stage 1 Cool) and Electric Heat (W1) will be disabled.

Error Detection/ Notification

•  Condensate overflow, door open or economizer can be set in Service Menu 175

•  Connect external dry switch at S1 and SC. See wiring diagram.

0-10 VDC Fan Operation

•  Change SM112= 01 or 02

2| 2 Stage Heat /1 Stage Cool Fan: Single Speed
3| 1 Stage Heat /1 Stage Cool Fan: 3-Speed
4| 2 Stage Heat /1 Stage Cool Fan: 3-Speed
5| 2 Stage Heat / 2 Stage Cool Fan: 2-Speed
6| Heat Only

Fan: Single Speed

7| Cool Only

Fan: Single Speed

8| Heat Only Fan: 2-Speed
9| Cool Only Fan: 2-Speed
10| Heat Only Fan: 3-Speed
11| Cool Only Fan: 3-Speed
12| Heat: TWF Cool: 2 Stage Cool Fan: 2-Speed
13| Heat: TWF Cool: 1 Stage Cool Fan: 3-Speed
14| Heat: 2 Stage Heat Cool: TWF Fan: 2-Speed
15| Heat: TWF Cool: TWF (Default) Fan: 2-Speed
111| Damper Configuration| 0 – Damper Continuous| Damper output is not available when being used as a fan speed.

0: G1 output runs continuously when thermostat is not in System OFF Mode. 1: G1 output cycles with a heat or cool demand.

1 – Damper Cycled with Demand (Default)
112| System Fan Type| 0 = On/Off Fan (Default)| 0: Uses available fan speeds per Service Menu 110

1: Uses GD output for 0-10 VDC fan*. User selection of speed.

HI Speed is set at SM 125-126,LO speed is set at SM 127, MED is set between HI-LO. 2: Uses GD output for 0-10 VDC fan*.

Modulates between Min and Max selections in SM 125-127*.

*Damper Output is Available at (G1) and runs per SM 111

---|---|---|---
1 = 0–10VDC FAN Hi-MED-LO Fan
2 = Proportional 0-10VDC Fan
113| 0-10 VDC Fan Ramping| 0 to 3 Minutes, 30 sec Increments

(Default 1:00)

| Sets how long it takes for the fan to transition between 0 VDC and 10 VDC when

SM112=1 or 2. The duration will be shorter if SM125 or SM126 are less than 10 VDC.

114| Valve Stoke Time| 30 Sec To 5 Min (Default 120)| Set the amount of time for a TWF valve to go from fully closed to fully Open.
120| Fan Control (Heating)| 0 – OFF for Heating (Gas/Oil Heat)| 0: The thermostat will not activate the fan with a heating demand. 1: The thermostat will activate the fan with heat demand.
1= Electric Furnace (DEFAULT)
122| YD Output Configuration| 0 = 4 – 20mA| Configures digital cooling output for 0-10VDC or 4-20mA DC
1 = 0 – 10 Volts (DEFAULT)
__

__

123

| WD Output Configuration| 0 = 4 – 20mA| Configures digital heating output for 0-10VDC or 4-20mA DC
1 = 0 – 10 Volts (DEFAULT)
124| GD Output Configuration| 0 = 4 – 20ma| Configures digital fan output for 0-10VDC or 4-20mA DC
1 = 0 – 10 Volts (DEFAULT)
125| GD Max Voltage, Heating Demand| 6 – 10 VDC (Default: 8)

12 – 20 mA (Default: 20)

| Depending on SM 124 setting, sets Fan HI speed voltage or current (mA) at terminal GD with demand for Heat.
126| GD Max Voltage, Cooling Demand| 6 – 10 VDC (Default: 10)

12 – 20 mA (Default: 20)

| Depending on SM 124 setting, sets Fan HI speed voltage or current (mA) at terminal GD with demand for Cool.
127| GD Min Voltage| 0 – 6 VDC (Default: 2)

4 – 12 mA (Default: 4)

| Depending on SM 124 setting, sets Fan LO speed voltage or current (mA) at terminal GD with no demand.
135| W1 Output Configuration| 0 – NC: Normally Closed Operation (Default)| Reverses the ON/OFF operation for W1. NC operation powers on with a demand. NO opreation powers off with a demand and will be on with no demand unless main power is removed from the thermostat.
1 – NO: Normally Open Operation
170| S1 Remote Sensor Input| 0= No Remote Sensors (Default)| 0: Remote temperature sensing is disabled.

1: The T8168 uses the remote sensor only for temperature sensing.

2: The T8168 averages the local and remote sensor for temperature sensing.

When using a remote sensor an open or short will turn off outputs and display either 2Ero(open) or 2Erc (closed). Fault detection settings are not used.

1= Remote Indoor Sensor Connected
2 = Remote Sensor Connected And Sensor

Averaging

171| S2 Pipe Sensor| 0 – Disabled (Default)| Enables fan coil pipe sensor operation. Connect a PECO pipe sensor or dry switch closure for change over from Summer (cold water) to Winter (hot water). 2-pipe operation uses the Cool 1 output for heating and cooling. Heat 1 is disabled. 4-pipe operation allows heat 1 in summer mode of operation.

Available when SM 110 = 1 through 5 or 14 through 16

1 – Two Pipe Operation
2 – Four Pipe Operation (use for 2-pipe with electric heat relay)
172| Pipe Sensor Threshold for Cooling| 50F to 72F (Default 60F)| Changes to Cool when pipe temp is below threshold. Available when SM 171 = 1 or 2
173| Pipe Sensor Threshold for Heating| 75F to 90F (Default 80F)| Changes to Heat when pipe temp is above threshold. Available when SM 171 = 1 or 2
174| Pipe Sensor Purge| 0 = Time| TEMP: Purge continues until a non-ambiguous condition is sensed.

TIME: A 3-minute purge is started. Once complete and still ambiguous mode all thermostat outputs are disabled for 1 hour.

Available when SM 171 = 1 or 2

1 = Temp (Default)
175| Fault Detection/ Setback

__

(requires SM170=0)

No remote probe

| 0 = Disabled (Default)| When enabled connect dry switch between S1 and SC.
1 = Active On Open| Displays “Door” in clock location, turn outputs OFF, blink red LED
2 = Active On Open| Displays “Fdd” in clock location, outputs function normally
3 = Active On Close| Displays “Err” on clock location, turn outputs OFF blink red LED
4 = Occupancy Sensor| Sets thermostat to setback with a closure at SC and S1 .
240| Number of Program Events| 2 or 4 Events (DEFAULT = 2)| When the T8168 is set up as programmable this sets the number of events per day. Events are OCC1, UNOCC1, OCC2, UNOCC2
250| Clock Format| 12 or 24 Hrs (Default = 12)| This service menu sets the clock format.
260| F or C| 0- Celsius| Determines temperature displays in Fahrenheit or Celsius
1- Fahrenheit (Default)
270| Fan Off Delay Heat| 0-99 Seconds (0-Default)| The amount of time (in seconds) the lowest available fan speed will run after the thermostat heating outputs are disabled
280| Fan Off Delay Cool| 0-99 Seconds (0-Default)| The amount of time (in seconds) the lowest available fan speed will run after the thermostat cooling outputs are disabled
290| Range Low| 50-90 F (50F- Default)| The lowest selectable temperature setpoint value
300| Range High| 50-90 F (90F Default)| The highest selectable temperature setpoint value
---|---|---|---
310| Setback Low| Off, 50-90 F (67F Default)| Accessed from Wi-Fi or by occupancy sensor detection. “Off” turns heating setpoint off.
320| Setback High| Off, 50-90 F (78F Default)| Accessed from Wi-Fi or by occupancy sensor detection. “Off” turns cooling setpoint off.
330| Zone Temp Offset| +/-9F (0F Default)| Zone Temperature offset adjusts the sensed Zone Temperature displayed, allowing calibra- tion in the field
340| Keypad Lockout| 0- No Key Pad Lockout (Default)| This function blocks access to certain features of the device. The Service Menu is still available if the key pad lockout is enabled.

If PIN is entered keypad lockout is overridden for 5 minutes.

1- Disables Schedule and System Keys
2 – Disables Schedule, System, And Fan Keys
3 – Disables All Keys
341| Enable Pin Access| 0=Disable, 1= Enable (Default = 0)| Applies a 3-digit access code to enter service menu 342
342| Set Pin| 000-999 (Default 000)| Selects pin access three-digit code.
350| Fan Mode| 1- On| ON: Fan is always on, regardless of demand.

User selections are: ON HI, ON MED, ON LO based on the number of fan speeds.

2- Auto| Auto- Fan is only on with heating or cooling demand User selections are: AUTO HI, AUTO MED, AUTO LO based on the number of fan speeds.
3- ON Or Auto (Default)| ON or Auto user can choose either selection. User selections are: AUTO HI, AUTO MED, AUTO LO, ON HI, ON MED, ON LO based on the number of fan speeds.
4 – Staged Only| Fan speed selected from available speeds by thermostat per Fan Access section. User selections are: AUTO or ON.
5- On Or Staged – Hotel Mode| ON- Fan is always on at user selected speed, regardless of demand

Auto Staged- Fan cycles off with demand. Fan speed is selected by thermostat from avail- able fan speeds.

360| System Mode| 0- Off, Auto| Sets the system modes the occupant is able to select

__

Hotel operation – For ease of use change available System modes to ON-AUTO

SM360=02

1- OFF, Heat, Cool, Auto (Default)
2- OFF, Heat, Cool
3- Heat, Cool, Auto
375| System Flush Enable| 0 = No Flush (Default)| ▲ ! WARNING: Service Menu 375 may disable fan operation during valve flush. Enables the flush function for fan coil systems. This feature should be set to 0

(zero) unless outputs are connected to hydronic heating or cooling valves. Failure to follow this instruction can result in damage to equipment and/or property.

1 = W1 Flush
2 = Y1 Flush
3 = W1 & Y1 Flush
376| Flush Duration| 1 To 3 Minutes (Default 1)| Defines how long to open the valve to perform the flush function
377| Flush Frequency| 0 = Every 24 Hrs (Default 0)

1 = Every 12 Hours

2 = Every 6 Hours

| Defines how often the flush is performed when output has remained inactive
380| Minimum Dead-band Adjustment| 3F (Default)| A changeover dead-band value prevents short cycling between heating and cooling modes. The value is adjustable to meet various HVAC system requirements.
1-10F, 1.5-5C
390| Pre-Occupancy Purge| 0 Hours (Default)| Energizes the lowest fan available for selected number of hours (0-3) prior to events Occ 1 and Occ 2. This featrure applies to Programmable thermostat operation.

This feature is disabled for 0-10 VDC proportional fan applications.

0-3 Hours
395| Temporary

Occupied Duration Limit

| 0-4 Hours (Default = 3)| This set the duration of a user override for programmable operation. 0: Will override the schedule until the next programmed event.

1,2,3,4: Sets the number of allowed hours of override after user adjustment. User can adjust override duration up to this limit of hours.

480| Minimum Off Time| 0-10 Minutes (Default 1 Minutes)| Sets the minimum off time for both the heat and cool output.
500| Programmable/ Intermittent Fan| 0- Disable (Default)| In programmable mode the fan will operate continuously during occupied periods or with demand during unoccupied/setback periods. In intermittent fan will operate based on the on and off times set in menus 501 and 502 whenever there is demand for fan.

This feature is disabled for 0-10 VDC proportional fan applications.

1 – Programmable Fan
2 – Intermittent Fan
3 – Intermittent Fan During Occupied Periods Only
501| Intermittent Fan On Time| 5 Minutes (Default)| Defines the duration in which fan low will be on. Fan On will be activated after Fan Off time has passed.
1-60 Minutes
502| Intermittent Fan Off Time| 25 Minutes (Default)| Defines the duration in which fan low will be off. Fan Off will be activated after Fan On time has passed. A selection of 0 will result in continuous Fan.
0-60 Minutes
520| Default Display Icons| 0- Time, Temp, SP (Default)| Icons that will be displayed in the default state.

__

NOTE: Setpoint will not be displayed if T8168 System Mode is OFF.

---|---|---|---
1- Time, Temp
2- Time
3- Temp
4- None
5 – Set Point Only
530| Revision| Displays Current Revision Information|
540| Factory Default Reset| 0- Disable (Default)| When enable is selected the device will return to factory default settings.
1- Enable
550| Wi-Fi Reset| Set to 1| Unit enters AP Mode and broadcasts SSID “T8168 XXXXX”
600| Cooling System Output Test| 0- Disable (Default)| Cool Operation is enabled and the associated output based on Service Menu 110. The output is activated for 10 minutes. The ON/OFF or 0-10 VDC Fan output will automatically turn on.
1- Stage 1 Cooling/Y1 (TWF)
2 – Stage 2 Cooling/Y2 (TWF)
610| Heating System Output Test| 0- Disable (Default)| Heat Operation is enabled and the associated output based on Service Menu 110. The output is activated for 10 minutes. The ON/OFF or 0-10 VDC Fan output will automatically turn on.
1- Stage 1 Heating/W1 (TWF)
2 – Stage 2 Heating/W2 (TWF)
620| Fan System Output Test| 0- Disable (Default)| If enabled is selected it will activate Based On Service Menu 110. The output will be enabled for 10 minutes. If a different menu is selected the output will be disabled. Wheth- er the fan output is a triac or a 0-10VDC/4-20mA is determined by Service Menu 112
1- Enable G Fan Output/GD Low
2 – Enable Y2 Fan Output/GD Med Cool
3 – Enable G1 Fan Output/GD Hi Cool
4 – Enable GD Med Heat
5 – Enable GD High Heat

TROUBLESHOOTING & FREQUENTLY ASKED QUESTIONS

In case of difficulty, try one of the following suggestions below.

assure proper wiring of power to (24 VAC-1) and (24 VAC-2) .

•  Check power to verify that there is 24 VAC available.

•  Default Display is set to “4” (None)| •  Check Service Menu 520.
If keys do not allow manual entry| •  Keypad Lockout may be enabled| •  Access Service Menu 340. Within this menu, select option “0” to assure there is no keypad lockout (so manual entry is enabled).
Service Menu does not display| •  PIN access is enabled

•  Buttons were not pressed simultaneously

| •  Access requires the three digit code set by the installer.

•  Wait for unit to return to default display and retry.

Err In Clock Dispay| •  Indicates a service fault input| •  Indicates service is required.
Door in Clock Display| •  Door or window is open| •  Close door and /or window to clear fault.
Fdd in Clock Display| •  Indicate an economizer or other system fault| • Indicates service is required.
If no heating or cooling is running, but there is a call for heat or cool (Heat/Cool appears on display) in Auto mode| •  Heating or cooling equipment is not operating

•  Minimum off time has not been met

| •  Check Service Menu 110 to assure that the correct option is selected to match the system type.

•  Check wiring, using output tests to verify (see Service Menus 600, 610, 620).

If heating or cooling system doesn’t respond| •  System type selection is incorrect| •  Check Service Menus 110 and 120 to assure that the correct option is selected to match the system type.
If heating and cooling equipment are running at the same time| •  System type selection is incorrect| •  Check Service Menu 110 to assure that the correct option to match the system type is selected.
•  Verify wiring connections| •  Separate the heating and cooling wires, using output tests to verify (see Service Menus 600, 610, 620).
If Demand Indicator light is red| •  Heating is occurring| •  No action is required.
If Demand Indicator light is green| •  Cooling system is running| •  No action is required.
Fan outputs turned off after 3-minutes| •  Pipe sensor is connected and water temperarture between hot water and cold water set points| •  Building Boiler or Chillers may be turned off.

•  See Service Menus 171, 172, 173 & 174

Menu Item Not available| •  Some service menus are disabled when not in use or feature is not available.| •  Verify system type selection and feature selection is correct.
Red LED is Flashing and code is in clock location| •  Fault is present on SC and S1 input| •  Check SM175 for code

•  If using a remote sensor, verify probe wiring.

BACnet® Communication

The T8168B-2 Thermostat is equipped with BACnet® IP or MS/TP wired Connections.
More detailed information is available using the QR code provided or on https://www.pecocontrolsystems.com in the connected controls location.

BACnet® IP Communication
This thermostat will broadcast a Wi-Fi network on power up. From your device Wi-Fi The network will appear as “T8168 #####”. Select this network and enter Password: 12345678, then press connect. Next Sign-In to open the BACnet Configuration Page at IP Address 10.10.0.1 on the T8168XXXX network. More information is available on our website.

MS/TP Wired Connections
Recommended wiring specification
22 -24 AWG Shielded twisted pair, Low Capacitiance

Installation

1. Care must be taken to ensure that the communication wiring does not touch the Shield/Ground.
2. Do not connect the Shield/Ground to earth ground or the controllers power ground.
3. Care should be taken to assure that polairty is maintained for all connections with shared power
4. This controller does not have an EOL termination or biasing.
5. Terminal 4A is Negative, 4B is positive and 4C is ground
6. When complete this thermostat will be part of a system that is not controlled by PECO. Follow system equipment specifications for approporate installation.

Visit: pecocontrolsystems.com for additional information.

© COPYRIGHT 2024 PECO, INC. ALL RIGHTS RESERVED.

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