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HEATER PART NO.
KFAEH2201H10 or
KFCEH0101H10
KFAEH2301H15 or
KFCEH0201H15
KFAEH2401H20 or
KFCEH0301H20
6. If only W3 is energized (JW1 is cut), there is no effect on
PCB. No heat is energized.
C. Accessories
Terminals AUX+ and AUX- are energized with 24 vdc when fan
is energized. The accessory kit KFAIR0101ACR is used to
connect an EAC or humidifier.
NOTE: Loads cannot be connected directly to AUX+ and AUX-.
Use the specified kit only.
D. Blower
1. Blower On Delay—To optimize comfort, there is a 30-sec
blower on delay in heat pump heating mode only.
2. Blower Off Delay—Smart Heat control uses a 60-sec off
blower delay, as opposed to the standard 90-sec delay.
III. SMART HEAT OPERATION
A. Cooling
The Smart Heat option controls cooling mode in same manner as
conventional heat pumps are controlled. The fan has a 90-sec delay
off/on cycle down.
CEPL130121-01
MOV1
SEC2
FS1
SEC1
R1
R30
R3
D5
R23
C6
Z5
C5
C2
1
R8
C13
R21
R9
C3
JW7
R20
C12
C10
R16
R13
R2
R19
R10
C9
R5
JW6
C8
R40
R18
R11
R41
C7
R15
1
R4
R27
XFORM
T1
DUMMY
T2
240 VAC
F1
T3
COMMON
FAN
HI
240
VAC
DUMMY
LO
F2
Fig. 39—Smart Heat Printed-Circuit Board (PCB)
TABLE 10—ELECTRIC HEATER STAGE LIMITING
Heater Stage
10 kw Non-Fused
15 kw Fused
20 kw Fused
—47—
ST1
LOW VOLTAGE
TERMINAL
R
BOARD
C
R7
R6
Y
Z4
G
R12
C11
O
R17
W2D
Z3
W 2T
JW1
JW1
(CUT WHEN
Z2
W 3
OUTDOOR
THERMOSTAT
JW8
Y o
IS USED)
AUX–
JW2
AUX+
(HIGH FAN
ONLY WHEN
K2
CUT)
RECEPTACLE
K3
STAGES (KW OPERATING)
W2T Only (JW1 cut)
1
2
3
6
3
8
5
10
B. Heat Pump Heating
The Smart Heat option does not control heating in the conventional
method. The PCB energizes compressor 30 sec before indoor fan
is energized. This allows indoor coil to heat up eliminating
cold-blow on start-up.
The electric heat is staged-on to allow continuous operation of heat
pump and electric resistance heat below balance point (below point
where heat pump cannot maintain dwelling temperature without
supplemental heat) independent of outdoor thermostats.
Although PCB has provisions for an outdoor thermostat, it is not
needed for staging. On cycle down, indoor fan remains on 60 sec
to recover heat stored in indoor coil.
C. Defrost
The Smart Heat PCB stages the correct amount of supplemental
heat during defrost. If too much heat is added, system stays in
defrost for completion of defrost cycle even though thermostat is
satisfied. On next cycle, 1 less element is energized during next
defrost period.
NOTE: If the signal from thermostat is interrupted (ie., thermo-
stat is satisfied) while unit is in defrost mode, the defrost cycle will
be completed before unit shuts down.
A94127
W2T and W3
3
4
9
9
11
15
15
20
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Troubleshooting
