White Rodgers F145-1378 Troubleshooting

REMOTE SENSORS

MAXIMUM SENSING LOCATIONS PER THERMOSTAT

Staging

Thermostat Model

Number

Indoor Sensing Locations

Remote Sensor

Total

(Max.)

Thermostat

Onboard

Sensor

Remote

Sensor

Sensor Set Up

Priority

Assignment (LO/AVG/HI)

Allows

Outdoor

Remote

Sensor

1F90-371

1F96-344

1F97-1277 (Blue)

1F97-371

1F97-391

Clip Jumper W922 and

*Using a Remote Sensor On This Model Requires the Onboard Thermostat Sensor To Be Off. **Allows A Sensor Priority of LO, AVG., or HI To Be Assigned To The Onboard Thermostat Sensor In Addition Remote Sensors. ***Accepts One Remote Sensor, Indoor or Outdoor.

1F95-391

1F95-377

1F95-371

1F95-1277 (Blue)

1F94-371

1F93-380

ON or OFF

Single

Stage

Enable Sensor in Menu

Enable Sensor in Menu Enable Sensor in Menu Enable Sensor in Menu Enable Sensor in Menu Enable Sensor in Menu Enable Sensor in Menu

Clip Jumper W922 and

Enable Sensor in Menu

1 OFF*

OFF*

With

+ + +

Up to 3

- -

Yes Yes***

Yes Yes

Yes

Yes Yes Yes

Yes***

Yes** Yes**

Yes** Yes** Yes**

REMOTE SENSOR CALCULATED PRIORITY AVERAGEREMOTE SENSOR CALCULATED PRIORITY AVERAGE

REMOTE SENSOR CALCULATED PRIORITY AVERAGE

Consult Maximum Sensing Locations Per Thermostat chart on page 6 to determine how many sensors a thermostat will accept.

Tables 1-3 show how priority (LO, AVG, HI) effects the room temperature calculation. The example below table three shows the calculation of each remote sensor and how it uses them to arrive at room temperature average.

Table 1: Remote Sensor A configured as a LO priority sensorTable 1: Remote Sensor A configured as a LO priority sensor

Table 1: Remote Sensor A configured as a LO priority sensor

RemoteRemote

Remote

SensorSensor

Sensor

Pr ior ityPr ior ity

Pr ior ity

SensorSensor

Sensor

Pr ior ityPr ior ity

Pr ior ity

Mu lti pli erMu lti pli er

Mu lti pli er

Room TemperatureRoom Temperature

Room Temperature

Averaging CalculationAveraging Calculation

Averaging Calculation

SA LO 1 70°F (Sensor Temp.) 1 x 70 = 70 (Priority Multiplier x Room Temp.)

Table 2: Remote Sensor B configured as a AVG priority sensorTable 2: Remote Sensor B configured as a AVG priority sensor

Table 2: Remote Sensor B configured as a AVG priority sensor

RemoteRemote

Remote

SensorSensor

Sensor

Pr ior ityPr ior ity

Pr ior ity

SensorSensor

Sensor

Pr ior ityPr ior ity

Pr ior ity

Mu lti pli erMu lti pli er

Mu lti pli er

Room TemperatureRoom Temperature

Room Temperature

Averaging CalculationAveraging Calculation

Averaging Calculation

SB AVERAGE 2 75°F (Sensor Temp.) 2 x 75 = 150 (Priority Multiplier x Room Temp.)

Table 3: Remote Sensor C configured as a HI priority sensorTable 3: Remote Sensor C configured as a HI priority sensor

Table 3: Remote Sensor C configured as a HI priority sensor

RemoteRemote

Remote

SensorSensor

Sensor

Pr ior ityPr ior ity

Pr ior ity

SensorSensor

Sensor

Pr ior ityPr ior ity

Pr ior ity

Mu lti pli erMu lti pli er

Mu lti pli er

Room TemperatureRoom Temperature

Room Temperature

Averaging CalculationAveraging Calculation

Averaging Calculation

SC HI 4 80°F (Sensor Temp.) 4 x 80 = 320 (Priority Multiplier x Room Temp.)

The example below lists three sensors each with a different priority and room temperature. All three sensors are combined in the calculation to display the average temperature. The priority multiplier shown in the tables above causes a sensor with low priority to carry less weight in the calculated average. A sensor with a HI priority setting contributes more to the calculated average. Assume that the building in which the thermostat is located has three indoor remote sensors (SA, SB, SC) that have different room temperatures (70, 75, 80). The calculated average will be displayed as the room temperature shown in the example below.

Example: Remote Sensors A, B, and C configured as a LO, AVG, and HI priority sensorsExample: Remote Sensors A, B, and C configured as a LO, AVG, and HI priority sensors

Example: Remote Sensors A, B, and C configured as a LO, AVG, and HI priority sensors

RemoteRemote

Remote

SensorSensor

Sensor

Pr ior ityPr ior ity

Pr ior ity

SensorSensor

Sensor

Pr ior ityPr ior ity

Pr ior ity

Mu lti pli erMu lti pli er

Mu lti pli er

Room TemperatureRoom Temperature

Room Temperature

Averaging CalculationAveraging Calculation

Averaging Calculation SA LO 1 70°F (Sensor Temp.) 1 x 70 = 70 (Priority Multiplier x Room Temp.) SB AVERAGE 2 75°F (Sensor Temp.) 2 x 75 = 150 (Priority Multiplier x Room Temp.) SC HI 4 80°F (Sensor Temp.) 4 x 80 = 320 (Priority Multiplier x Room Temp.)

Avg. Calc. (540)/Sum Priority Mult. (7)

540/7 = 77°F (Calculated Displayed Temp.)

TECHNICAL HELP

172

www.white-rodgers.com

REMOTE SENSORS

Transformer

Red Jumper Wire

THERMOSTAT

24 VAC

Line

Voltage

Figure 1. Wiring for single transformer systems

RH W Y RC

Heating System

Cooling System

DO NOT REMOVE OR WIRE AROUND LIMIT AND SAFETY SWITCHES WHEN INSTALLING ISOLATION RELAYS.

WARNING

Troubleshooting ChartTroubleshooting Chart

Troubleshooting Chart

To function correctly and read temperature accurately, the thermostat must have constant 24-volt power. If the thermostat temperature is steadily dropping, reading low, or reads

08°08°

08° when a remote sensor is installed, it can be traced to one of the

three following conditions.

Co ndi tionCo ndi tion

Co ndi tion

TestTest

Test

Comment sComment s

Comment s

1. Loss of 24-volt power. On models with batteries, remove the batteries and re-install For the sensor to read correctly, thermostat. If the display is blank, check heating and cooling the 24-volt system power

mustmust

must

system to determine why 24-volt power is absent. be present. Some systems may

require an isolation relay* to provide constant power to the thermostat. Limit or safety devices in the equipment can also cause a power interruption.

2. A broken wire on S1, Disconnect sensor wires at thermostat. Attach a short piece Repair or replace the 3 wire

S2 and S3 or (+, SA, -) (2') of three-wire shielded cable to S1, S2 and S3 or (+, SA, shielded cable. Be sure the from the thermostat to -) on the subbase. Bring the remote sensor to the thermostat remote wire run is not parallel the remote. location and attach S1, S2 and S3 or (+, S, -) respectively. to line voltage wires that carry

Reattach thermostat. If the temperature begins to climb heavy inductive loads, or across (slowly), it is reading correctly. If it reads correctly with the 2' fluorescent light ballasts that length but improperly when attached to the wire run, it may cause an inductance to be

.tatsomreht eht ot dettimsnart.nur eriw eht ni tluaf a setacidni

3. A shorted or Because it is an electronic sensor, there are no Ohm values Replace remote sensor.

damaged remote sensor. to test. If correct conditions as listed in 1 & 2 above and the

temperature stays at or near

08°08°

08°, it indicates a shorted or

damaged remote sensor.

NoteNote

Note: Digital thermostats and remote sensors acclimate very slowly to temperature change. It may take an hour or more for the temperature to acclimate to the room temperature from a low temperature reading as outlined above. To expedite the room temperature display use the reset instructions listed in the installation instructions for the thermostat model you are working with. When reset, the thermostat will default to a room temperature of 70° and begin sensing room temperature. Be sure to reconfigure the installer menu for a remote sensor because the reset function may cancel remote sensing.

REMOTE SENSOR

TROUBLESHOOTING

* Isolation Relay Wiring

Note: The diagram below shows how to attach an isolation relay to

the “W” or “Y” circuit to provide constant power on power stealing thermostats. This willl allow the thermostat to operate properly with a remote sensor.

Figure 1 shows a single transformer heating/cooling system, with isolation relays installed in the heating (W) and cooling (Y) circuits. To simplify the diagram, limit and safety switches are not shown here, although they will be found either in the low or high voltage circuit. Limit and safety switches must be retained. Refer to the equipment manufacturer’s system wiring diagram for the location of limit and safety switches.

www.white-rodgers.com

TECHNICAL HELP

173

+ 2 hidden pages

White Rodgers F145-1378 Troubleshooting

Specifications and Main Features

Frequently Asked Questions

User Manual