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XPG15 SERIES
Mode (O Input not Present)
HEATING
K1 – Outdoor Fan (Normally Closed)
K2 – Reversing valve & RL output
K3 – Compressor Y1 out
K4 – W out
ASCD – Anti
−
short Cycle Delay
Power
−
Up
Thermostat Call
for heat
First Stage
Only?
Enter HP Inactive /
Display Code
K3 = OFF
K1, K2, K4 = ON
No
Ambient
Tempeture is
less than
32
F?
Yes
Ambient
Temperature is
less than 32
F?
Yes
Is 5 minute
ASCD Timer
Expired?
No
Energize K3
(Comp
Contactor)
Yes
No
Enter HP
Inactive / Display
Code
K3 = OFF
K1, K2, K4 = ON
First Stage
Demand
Satisfied?
Yes
Remain Inactive,
K1, K2, K3 =
OFF
K4 = ON
Yes
No
Return from
Inactive criteria
satisfied and Y1
Active?
New Thermostat
Heat Demand?
No
No
Yes
K1, K2, K3 = ON
and K4 = OFF
(Power Defrost)
Yes
Ambient
Temperature less
than 32
F?
Hi
−
Ps Trip?
No
Lo
−
Ps Trip?
No
Demand
Satisfied?
No
No
Yes
De
−
energize K3
(Comp Contactor)
Fifth Trip in this
Heating Demand?
Hi
−
Ps Lockout / Display Code
Yes
Yes
De
−
energize K3
(Comp Contactor)
Fifth Trip in this
Heating Demand?
Yes
Lo
−
Ps Lockout /
Display Code
No
First Stage
Demand
Satisfied?
K1, K2, K4 =
OFF
Exit HP Inactive /
Display Normal
Operation Code
No
Yes
No
Yes
Does O Become
Active?
No
End Heating
Operation – See
Cooling Mode
Yes
Calibration
Sequence
Yes
No
No
A
DEFROST CONTROL (ON
−
BOARD RELAYS)
Figure 27. Heating Mode Operation