Lennox XC21 Series User Manual

Page 58
XC21
Y1 DEMAND
DISCHARGE
SENSOR
(RT28)*
COMPRESSOR
CONTACTOR
ENERGIZED
HIGH
PRESSURE
SWITCH (S4)
COMPRESSOR
CONTACTOR
DE−ENERGIZED
COMPRESSOR
ANTI−SHORT
CYCLE TIMER
BEGINS
INCREMENT
5−STRIKE
COUNTER
1
LED ALERT
CODE / OR
MODERATE
ALERT 414
DISPLAYED
ANTI−SHORT
CYCLE TIMER
ENDS
COMPRESSOR
CONTACTOR
ENERGIZED
DISCHARGE
SENSOR (RT28)
IS AT OR
BELOW 225ºF
WAITING FOR
TEMPERATURE
DROP TO OR
BELOW 225ºF
5−STRIKE
COUNTER
REACHES 5
WITHIN A SINGLE
Y1 DEMAND
DISCHARGE
SENSOR (RT28)
LOCKOUT
LED ALERT
CODE / OR
CRITICAL
ALERT 415
CLEARED
SERVICE
REQUIRED
2
LED ALERT
CODE / OR
MODERATE
ALERT 414
CLEARED
NORMAL
OPERATION
CLOSED
CLOSED
OPEN
OPEN
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 Toucht 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 air
conditioner control’s (A175) R terminal, or placing a jumper
on the field test pins (E33) between 1 to 2 seconds.
NO
*
If temperature is at or above 279ºF.
YES
Figure 34. High Discharge Temperature (RT28) Sensor Sequence of Operation

Lennox XC21 Series Specifications

General

SEER Rating	Up to 21.00
Sound Rating	As low as 69 dB
Energy Star Certified	Yes
Refrigerant	R-410A
Cooling Capacity	2 to 5 tons
Warranty	10-year limited warranty on compressor and covered components