Bryant Preferredt Series Installation Instructions Manual page 47

used to operate a ventilator, damper, system blower, or other auxiliary device. There
are two terminals, D1 and D2.
If it is desired to operate a ventilator or other device, the D1 and D2 terminals can
be connected directly to the equipment. This will provide a closed contact for the
specified number of minutes per hour. See Option 19.
If timed control of the system blower is required, the dry contact can be used for
this function. The G terminal can be connected to one of the dry contact terminals
with the other terminal being connected to Rc and/or Rh for timed control of the
fan. Note that this is not the same as programmable fan Option 30.
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.
45