Instruction manual

45
Programmable Fan (programmable models only)
The fan output can be programmed based on period of the day. When programming
for each day and period the fan can be set to On or AUTO. If the fan button is
pressed to change from On to Auto or vice versa when programmable fan has been
enabled, the manual change will only remain in effect until the next program
period, when the programmable fan setting will be changed per the scheduled
setting.
Dry Contact
On the programmable models, the dry contact that can be used for control of an
auxiliary device. The dry contact may be configured to be closed for a specific
number of minutes per hour for each period of the program schedule. This can be
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.