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Service Manual -
HRG18xxS1P
508206-01
Issue 2140
Page 51 of 83
Y1 DEMAND
OR COOLING
DEMAND
HIGH
PRESSURE
SWITCH (S4)
CONTACTOR
ENERGIZED
HIGH
PRESSURE
SWITCH (S4)
CONTACTOR
DE-ENERGIZED
ANTI-SHORT
CYCLE TIMER
BEGINS
INCREMENT
5-STRIKE
COUNTER
1
LED ALERT
CODE / OR
MODERATE
ALERT 412
DISPLAYED
ANTI-SHORT
CYCLE TIMER
ENDS
HIGH
PRESSURE
SWITCH (S4)
WAITING FOR
PRESSURE
SWITCH TO
CLOSE
5-STRIKE
COUNTER
REACHES 5
WITHIN A SINGLE
Y1 DEMAND
HIGH
PRESSURE
SWITCH (S4)
LOCKOUT
LED ALERT
CODE / OR
CRITICAL
ALERT 413
CLEARED
SERVICE
REQUIRED
2
LED ALERT
CODE / OR
MODERATE
ALERT 412
DISPLAYED
NORMAL
OPERATION
CLOSED
CLOSED
OPEN
OPEN
OPEN
CLOSED
CLOSED
TOP CAP
SWITCH (S173)
CLOSED
SERVICE
REQUIRED
2
1.
The thermostat terminates demand when the contactor is
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.
Figure 23. High Pressure Switch (S4) Sequence of Operation (All Versions)