Lennox XP25-024-230-01, Installation And Service Procedure

Page: 56 / 89

Page 56
XP25
Component Testing
Section Table of Contents
High and Low Pressure Switch Operation, Checkout and
Status / Error Codes
56 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reversing Valve Operation, Checkout and Status / Error
Codes
60 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compressor Operation, Checkout and Status / Error
Codes
62 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compressor Sound Cover 65 . . . . . . . . . . . . . . . . . . . . . .
Charge Compensator (XP25-024-230-XX and
XP25-048-230-XX only)
66 . . . . . . . . . . . . . . . . . . . . . . . .
Discharge Muffler (Heat Pumps only) 66 . . . . . . . . . . . .
Liquid Line Bi-Flow Filter Drier (Heat Pumps only) 67 .
Check Expansion Valve (Heat Pumps only) 68 . . . . . . .
Top Cap Switch Operation, Checkout and Status / Error
Codes
70 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reactor Operations, Checkout and Status /
Error Codes
71 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Line Filter (Electromagnetic Compatibility Circuit - EMC)
Operations, Checkout and Status / Error Codes
71 . . .
Outdoor Fan Operation and Checkout 72 . . . . . . . . . . .
Ferrites 74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outdoor Control Operation, Checkout and Status / Error
Codes
75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Sensor Operations, Checkout and Status / Error
Codes
76 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Variable-Capacity Inverter Control Operation, Checkout
and Status / Error Codes
79 . . . . . . . . . . . . . . . . . . . . . . .
Emergency 24VAC Operation 84 . . . . . . . . . . . . . . . . . . .
High and Low Pressure Switch Operation, Checkout and Status / Error Codes
OPERATION :
The unit's pressure switches (LO PS - S87 and HI PS - S4) are factory-wired into the control on the LO-PS and HI-PS
terminals, respectively.
Low Pressure Switch (LO-PS) — See figure 35 for low pressure switch sequence of operation.
High Pressure Switch (HI-PS) — See figure 36 for high pressure switch sequence of operation.
Pressure Switch Event Settings
The following pressures are the auto-reset event value triggers for low and high pressure thresholds:
•
High Pressure (auto-reset) - trip at 590 psig; reset at 418.
•
Low Pressure (auto-reset) - trip at 40 psig; reset at 90.
CHECKOUT
Using a multimeter set to ohms with the terminals disconnected from the control board, check the resistance between the
two terminals of the pressure switch. If the resistance reading is 0 ohms, the switch is closed.
S4
HIGH
PRESSURE
SWITCH
S87
LOW
PRESSURE
SWITCH
Figure 34. Verifying High Pressure and Low Pressure Switch Operation