Lennox XC25-024-230-01 Installation And Service Procedure page 49

HIGH
PRESSURE
Y1 DEMAND
SWITCH (S4)
CONTACTOR
DE-ENERGIZED
OPEN
ANTI-SHORT
CYCLE TIMER
BEGINS
INCREMENT
5-STRIKE
COUNTER
LED ALERT
CODE / OR
MODERATE
ALERT 412
DISPLAYED
ANTI-SHORT
CYCLE TIMER
ENDS
HIGH
PRESSURE
SWITCH (S4)
SERVICE
2
REQUIRED
WAITING FOR
PRESSURE
OPEN
SWITCH TO
CLOSE
Figure 30. High Pressure Switch (S4) Sequence of Operation (All Versions)
CLOSED
HIGH
PRESSURE
OPEN
SWITCH (S4)
The thermostat terminates demand when the contactor is
1.
de-energized. If demand is satisfied when alarm is not active, the
5-strike counter resets.
2. Lockouts can be reset by cycling power off to the outdoor control
(A175) R terminal.
5-STRIKE
COUNTER
REACHES 5
WITHIN A SINGLE
1
Y1 DEMAND
HIGH
PRESSURE
SWITCH (S4)
LOCKOUT
LED ALERT
CODE / OR
CRITICAL
ALERT 413
CLEARED
CLOSED
CLOSED
49
TOP CAP
CLOSED
SWITCH (S173)
CLOSED
SERVICE
REQUIRED
LED ALERT
CODE / OR
MODERATE
ALERT 412
DISPLAYED
CONTACTOR
ENERGIZED
2
NORMAL
OPERATION
XC25