Lennox SLP99UHV Series Unit Information page 33

Integrated Control Diagnostic Codes (Continued)
Code Diagnostic Codes/Status of Equipment
E402 LSOM - Outdoor unit system pressure trip.
LSOM - Compressor short-cycling (Running less than
E403
4 minutes).
E404 LSOM - Compressor rotor locked.
E405 LSOM - Compressor open circuit.
LSOM - Compressor open start circuit.
E406
E407 LSOM - Compressor open run circuit.
LSOM - Compressor contactor is welded.
E408
E409 LSOM - Compressor contactor is welded.
OPERATING
SEQUENCE
System
Step
Condition
NO CALL FOR DEHUMIDIFICATION
Normal Operation 1
BASIC MODE (only active on a Y1 thermostat demand)
Normal Operation 1
Dehumidification
2
Call
PRECISION MODE (operates independent of a Y1 thermostat demand)
Normal Operation 1
Dehumidification
2
call
Dehumidification
1
call ONLY
On-board links at indoor unit with a single-stage outdoor unit:
With Condensing unit - Cut W914 (R to DS) on SureLight
With Heat Pump - Cut W914 (R to DS) & W951(R to O) on SureLight
control.
*CS 7500 thermostat only
OPERATING SEQUENCE
SLP99UHV and Single-Stage Outdoor Unit
SYSTEM DEMAND
Demand Relative Humidity
1st
O G Status
stage
On On On Acceptable
On On On Acceptable
On On On Demand
On On On Acceptable
On On On Demand
On On On Demand
Action Required to Clear and Recover
Compressor ran over 18 hours in air conditioning mode.
Outdoor unit pressure trip. Check dirty coil, fan motor,
refrigerant charge.
Compressor short cycling (Running less than 4 minutes).
Check capacitor, wiring, hard start kit , replace
Compressor.
Check compressor for hot (cool down) , check pressures,
fan motor etc. Replace compressor if unable to get circuit
to close and compressor to operate.
Replace contactor.
TABLE 15
Compressor
D*
24
High
VAC
24
High
VAC
0
High
VAC
24
High
VAC
0
High
VAC
0
High
VAC
®
control;
Page 33
SYSTEM RESPONSE
Blower
Comments
CFM
(COOL)
Compressor and indoor
100% blower follow thermostat
demand
100%
Thermostat energizes Y1
and de-energizes D on a
call for de-humidification
70%
100%
Dehumidification mode
begins when humidity is
greater than set point
70%
70%
door unit energized after
point has been reached in
® order to maintain room
humidity setpoint.