Payne PG9MXA Installation, Start-Up, And Operating Instructions Manual page 54

CONTINUOUS BLOWER MODE
When the R to G circuit is closed by the thermostat, the blower
motor BLWM will operate on continuous-blower speed (can be
set to LO HT, HI HT, or COOL speed). Factory default is LO HT
speed. Terminal EAC-1 is energized as long as the blower motor
BLWM is energized.
During a call for heat, the blower BLWM will stop during igniter
warm-up (17 seconds), ignition (7 seconds), and blower-ON
delay (66 seconds), allowing the furnace heat exchangers to heat
up more quickly, then restarts at the end of the blower-ON delay
period at LO HT or HI HT speed respectively.
In high-heat, the furnace control CPU will hold the blower motor
BLWM at HI HT speed during the selected blower-OFF delay
period before reverting to continuous-blower speed.
When the thermostat "calls for low-cooling", the blower motor
BLWM will switch to operate at low-cool speed (same speed as
LO HT). When the thermostat is satisfied, the blower motor
BLWM will operate an additional 90 seconds on low-cool speed
before reverting back to continuous-blower speed.
When the thermostat "calls for high-cooling", the blower motor
BLWM will operate at COOL speed. When the thermostat is
satisfied, the blower motor BLWM will operate an additional 90
seconds on COOL speed
continuous-blower speed.
When the R to G circuit is opened, the blower motor BLWM will
continue operating for an additional 5 seconds, if no other
function requires blower motor BLWM operation.
Continuous Blower Speed Selection from Thermostat - - To
select different continuous-blower speeds from the room
thermostat, momentarily turn off the FAN switch or push-button
on the room thermostat for 1 - - 3 seconds after the blower motor
BLWM is operating. The furnace control CPU will shift the
continuous- blower speed from the factory setting of LO HT to
HI HT speed. Momentarily turning off the FAN switch again at
the thermostat will shift the continuous-blower speed from HI HT
to COOL. Repeating the
continuous-blower speed from COOL to LO HT speed. The
selection can be changed as many times as desired and is stored
in the memory to be automatically used following a power
interruption.
HEAT PUMP
(See Fig. 52, 53, 54 and 55 for thermostat connections)
When installed with a heat pump, the furnace control
automatically changes the timing sequence to avoid long blower
off times during demand defrost cycles. When the R to
W/W1-and-Y1 or R to W/W1-and-Y1-and-G circuits are
energized, the furnace control CPU will switch to or turn on the
blower motor BLWM at low cool speed (same speed as LO HT),
and begin a low-heat cycle. The blower motor BLWM will
remain on until the end of the prepurge period, then shut off for
24 seconds then come back on at LO HEAT speed. When the
W/W1 input signal disappears, the furnace control begins a
normal inducer post-purge period and the blower remains running
at LO HT speed. If the R-to-W/W1-and-Y1-and-G signals
disappear at the same time, the blower motor BLWM will remain
on for the selected blower-OFF delay period. If the R-to
W/W1-and-Y1 signals disappear, leaving the G signal, the blower
motor BLWM will remain on for the selected blower-OFF
delay period then switch to continuous-blower speed.
When the R-to W/W1-and-Y/Y2, R-to-W/W1-and-Y/Y2-
and-G, R-to W/W1-and-Y1-and-Y/Y2,
W1-and-Y1-and- Y/Y2-and-G circuits are energized the
furnace control CPU will switch to or turn on the blower motor
BLWM at COOL speed, and begin a high-heat cycle. The
blower motor BLWM will remain on until the end of the
prepurge period, then shut off for 24 seconds then come back
on at HI HT speed. When the W/W1 input signal disappears,
before reverting back to
procedure will shift the
or R-to-W/
the furnace control begins a normal inducer post-purge period
and the blower switches to COOL speed after a 3 second delay.
If the R-to-W/W1-and-Y/Y2-and-G
W/W1-and-Y1-and- Y/Y2-and-G signals disappear at the same
time, the blower motor BLWM will remain on for the selected
blower-OFF delay period. If the R-to W/W1-and-Y/Y2 or
R-to-W/W1-and-Y1-and-Y/Y2 signals disappear, leaving the G
signal, the blower motor BLWM will remain on for the selected
blower- OFF delay period then switch to continuous-
blower speed.
COMPONENT SELF-TEST
NOTE: The furnace control component test allows all
components to run for a short time; except the gas valve and
humidifier terminal HUM are not energized for safety reasons.
The EAC-1 terminal is energized when blower is energized. This
feature helps diagnose a system problem in case of a component
failure. The component test feature will not operate if any
thermostat signal is present at control and not until all time delays
are completed.
To Begin Component Self-Test:
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
or death.
Blower access panel door switch opens 115-v power to control
board. No component operation can occur. Caution must be
taken when manually closing this switch for service purposes.
1. Remove blower access door.
2. Disconnect thermostat R lead from furnace control.
3. Manually close blower door switch.
4. For approximately 2 sec, short (jumper) the C
terminal on control to the TEST/TWIN 3/16-in. quick-
connect terminal on control until LED turns off. Remove
jumper from terminals. (See Fig. 37.)
NOTE: If TEST/TWIN and C
longer than 2 sec, LED will flash rapidly and ignore component
test request.
Component test sequence for 2-stage furnace is as follows:
a. LED will display previous status code 4 times.
b. Inducer motor starts on high-speed and continues to
run until Step g of component test sequence.
c. Hot surface igniter is energized for 15 sec, then off.
d. Blower motor operates on LO-HT speed for 10 sec.
e. Blower motor operates on HI-HT speed for 10 sec.
f. Blower motor operates on COOL speed for 10 sec.
g. Inducer motor goes to low-speed for 10 sec, then stops.
5. Reconnect R lead to furnace control, remove tape from
blower door switch, and re-install blower door.
6. Operate furnace per instruction on outer door.
7. Verify furnace shut down by lowering thermostat setting
below room temperature.
8. Verify that furnace restarts by raising thermostat setting
above room temperature.
OPERATE FURNACE
Follow procedures on operating instructions label attached
to furnace.
FURNACE RESTART
With furnace operating, set thermostat below room temperature
and observe that furnace goes off. Set thermostat above room
temperature and observe that furnace restarts.
54
or R-to
-24v
OM
-24v terminals are jumpered
OM