Compressor Operation, Checkout And Status / Error Codes - Lennox EL23XCV Series Manual

High Pressure Switch Protection Errors
System fault and lockout codes take precedence over system status codes (cooling, heating operating percentages or defrost/dehu-
midification). Only the latest active fault or lockout codes are displayed (if present). If no fault or lockout codes are active, then system
status codes are displayed. Alert codes are also displayed on the communicating thermostat.
Alert
Priority
Codes
The outdoor unit high pressure
E 412 Moderate
switch has opened.
The high pressure switch has
opened 5 times within one hour. As
E 413 Critical
a result, the outdoor unit is locked
out.

Compressor Operation, Checkout and Status / Error Codes

OPERATION:
The EL23XCV uses two different types of compressor, depending on the specific model. The EL23XCV-024, -036 and
-048 use a 380VAC three phase variable capacity rotary compressor specifically designed for unitary splits system and is
approved for use with HFC 410A refrigerant. The EL23XCV-060 unit uses a 380VAC three phase variable capacity scroll
compressor that is approved for use with HFC 410A refrigerant. The compressor, when connected to an inverter, is capa-
ble of operating in a running frequency range from 20 hertz up to a maximum of 70 hertz. (maximum hertz is dependent
on compressor size). The compressor speed is determined by thermostat demand and suction pressure when installed
with a conventional 24VAC non-communicating thermostat and by thermostat demand when installed with an S30/S40
thermostat.
CHECKOUT:
NOTE - The compressor motor winding resistance is the nominal resistance at 77F. When measuring compressor motor
winding resistance, the primary concern is the winding resistance between the different sets of terminals is within 10% of
each other. The actual winding resistance is impacted by temperature, refrigerant and oil. Do not automatically condemn a
compressor because the measured resistance is slightly higher or lower than the nominal resistance. Check for shorted/
open windings and for shorts to ground during testing.
FIGURE 30. Compressor Operation, Checkout and Status/Error Codes
TABLE 12. Outdoor Control 7-Segment Display Alert Codes
Alarm Description
Unit pressure is above the upper limit. System is shut down. The high pressure
switch opens at 590PSIG and closes at 418PSIG. Confirm that the system is properly
charged with refrigerant. Check for clogged TXV, blockage to indoor unit blower
motor, clogged refrigerant filter. Confirm that the outdoor unit is clean. The alarm
clears after the pressure switch closes or a power reset.
For heating, indoor CFM may be set too low. For zoning system, zone CFM may be
set too low.
Open high pressure switch error count reached 5 strikes. System is shut down. The
high pressure switch for HFC410A will open at 590PSIG and close at 418PSIG.
Confirm that the system is properly charged with refrigerant. Check condenser fan
motor, clogged TXV, blockage to indoor unit blower motor, stuck reversing valve or
clogged refrigerant filter. Confirm that the outdoor unit is clean. The alarm clears after
indoor power reset (24VAC power source to Outdoor Control)
ROTARY
COMPRESSOR
Possible Causes and Clearing Alarm
SCROLL
COMPRESSOR
(EL23XCV-060 only)
EL23XCV-024
EL23XCV-036
EL23XCV-048
EL23XCV-060
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0.883 0.883 0.883
0.883
0.883 0.883
0.705 0.705 0.705
0.587 0.587
0.587