Lennox XP21 Series Installation Instructions Manual page 38

Y1 DEMAND
SWITCH (S4)
COMPRESSOR
CONTACTOR
DE−ENERGIZED
OPEN
COMPRESSOR
ANTI−SHORT
CYCLE TIMER
MODERATE
ANTI−SHORT
CYCLE TIMER
COMPRESSOR
CONTACTOR
ENERGIZED
SWITCH (S4)
SERVICE
2
REQUIRED
WAITING FOR
OPEN
506601−01
HIGH
PRESSURE
CLOSED
HIGH
PRESSURE
OPEN
SWITCH (S4)
1
If 5−strike counter has four or less strikes when Y1 demand is terminated
or satisfied, the strike counter will reset to zero. In a icomfort Touch
thermostat enabled setup, the thermostat will terminate demand when the
compressor contactor is de−energized. If demand is satisfied when alarm
is not active, the 5−strike counter will reset.
2
Lockouts can be reset by either cycling power off to the heat pump con-
trol's (A175) R terminal, or placing a jumper on the field test pins (E33) be-
tween 1 to 2 seconds.
BEGINS
INCREMENT
5−STRIKE
1
COUNTER
LED ALERT
CODE / OR
ALERT 412
DISPLAYED
ENDS
HIGH
PRESSURE
CLOSED
PRESSURE
CLOSED
SWITCH TO
CLOSE
Figure 30. High Pressure Switch (S4) Sequence of Operation
COMPRESSOR
CONTACTOR
ENERGIZED
CLOSED
5−STRIKE
COUNTER
REACHES 5
WITHIN A SINGLE
Y1 DEMAND
HIGH
PRESSURE
SWITCH (S4)
LOCKOUT
LED ALERT
CODE / OR
CRITICAL
ALERT 413
CLEARED
LED ALERT
CODE / OR
MODERATE
ALERT 412
DISPLAYED
Page 38
®
SERVICE
2
REQUIRED
NORMAL
OPERATION