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Delay, transfer from standby to electric – if the unit was operating in SB for more than 1 minute, the
follow-up transfer back to electric engages a 4-minute delay before the HP compressor relay is activated
and any of the electric stages are activated. The blower will react to the call for heat, but the elements
will stay off for 4 minutes in order for the blower to cool down the furnace heat exchanger.
SB (Gas) 5-Minute Safety – when in the standby mode (see previous section) there is now a 5-minute
timer which begins at each heat call. If after the 5 minutes the ST sensor is less than 85°, the logic board
itself goes into an automatic reset and restart. This simply means it attempts to begin the heat cycle using
electric in case the furnace did not ignite or "out of gas". However, if it is in the SB mode because of
Load Control it will still remain SB and try the gas furnace again. The system will never go back to
electric if you have a Load Control on-peak or A1 tab high. Note: Handheld can disable (must have latest
firmware chips).
Blower operation – the air handler or fossil fuel furnace blower is operated from its own fan center (G
screw). The activation of this "G" input is either directly from a heat pump (total electric system)
roomstat "G" screw or in the case of dual heat from the furnace interface module (WF-EZ3, LGR3, EM3,
etc.). The interface module and its wiring or association with the room thermostat completely controls the
blower. There is nothing on or within the WarmFlo control board itself which has anything to do with the
blower function.
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Delay on/delay off – within all interface modules there is an approximate 10 to 15 second
blower on delay and a 1-minute blower off delay. In the case of a heat pump stat, this can be
bypassed by taking the stat "G" screw directly to the interface module tab "G1" (multi-wire
stat only).
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Multi-speed blower – see page 24 and associated hookup instructions.
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Using E tab with HP stat emergency output – see previous "E-tab" section for blower
operation caution.
07/31/2007
29
HI320
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