Carrier PERFORMANCETSERIES EDGER THERMIDISTATT CONTROL TP-NRH-A Installation Instructions Manual page 59

See Wiring Diagrams for more information.
Relays
This thermostat uses latching relays. When the thermostat loses power, the relays
will remain in their last position until power is restored and all relays are reset to
their correct position. Out of the box, the outputs may appear to be On when the
thermostat is not powered. This is normal. Output states should only be checked
when the thermostat is powered.
Temperature Offset After Power Cycle
To compensate for internal heat build−up from the electronics in the thermostat,
the thermostat will add an offset to the actual temperature that it measures. If the
thermostat power is cycled quickly, one can witness an immediate increase in the
actual temperature displayed due to this added offset. The thermostat display will
return to the actual room temperature after several minutes of operation.
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