GF - A 8
Furnace Sequences Of Operation
High Heat Inducer Learning Routine
· When the furnace IFC receives a digital signal for
100% (high) heat from the comfort control it will
begin the PS-3 inducer learning routine.
· The furnace will start the heating cycle in 65%
(medium) heat, if not already on, and then begins the
PS-3 inducer learning routine.
· The furnace IFC will send a digital signal to the
variable speed inducer drive to run the inducer
motor at the preset factory 100% (high) heat
RPM.
· The furnace IFC waits for PS-3 pressure switch
to close. A 24 Volt AC signal is sent to the furnace
IFC when the pressure switch closes.
· If PS-3 does not close at the factory preset 100%
(high) heat RPM, the furnace IFC will continue to
signal the variable speed inducer drive to increase
the inducer speed in steps until PS-3 closes or
until the maximum RPM for 100% (high) heat is
reached.
· The furnace IFC enters a time delay so that the
heat exchanger and the recuperative cell warm up to
their high heat operating temperature. At the end of
this time delay, the inducer discharge air temperature
will be at its high heat operating temperature and the
density of the products of combustion will be
stabilized.
· The furnace will now signal the variable speed inducer
drive to reduce the inducer speed in steps until
PS-3 opens.
· When PS-3 opens, the furnace IFC will NOTE
the inducer motor RPM.
· The furnace IFC then adds an additional number
of RPM to the 100% (high) heat inducer motor
NOTED RPM until PS-3 closes.
· The furnace IFC now stores this learned inducer
operating RPM for 100% (high) heat in its memory.
· The furnace IFC will use this stored learned inducer
operating RPM for 100% (high) heat calls it receives in
the future.
· If PS-3 is not closed when the inducer reaches its
maximum RPM, the furnace IFC will signal the
variable speed inducer drive to reduce the inducer
Motor speed in steps to its low heat LEARNED
SPEED.
· The furnace IFC flashes its Red Fault LED three
times repeatedly and also sends an Alert message to
the comfort control. The furnace IFC will keep
operating at low heat for 10 minutes and then retry
the PS-3 learning routine.
Note:
Stage 1 = 40% (low) heat, Stage 2 = 100% (high) heat
3
2
5c
6b
3
6b
5c
2
High Heat Inducer Learning Routine
5c
3
3
5c
5c
3
6a
6a
5c
3
6a
5c
5c 3
6b
3
3
5c
3
6a
6b
3
5c
To Next Page
Loading...
