Page 20
505328M 06/09
Table 13.
LSOM LED Troubleshooting Codes
Status LED
Condition
Status LED
Description
Status LED Troubleshooting Information
Green Power LED ON
LSOM has power
24VAC control power is present at the LSOM terminal.
Green Power LED OFF
LSOM not powering up
Determine/verify that both R and C LSOM terminals are connected and voltage is present
at both terminals.
Red Trip LED ON
System and compressor
check out OK
1
Verify Y terminal is connected to 24VAC at contactor coil.
2
Verify voltage at contactor coil falls below 0.5VAC when off.
3
Verify 24VAC is present across Y and C when thermostat demand signal is present; if not
present, R and C wires are reversed.
Thermostat demand signal
Y1 is present, but
compressor not running
NOTE − During 5-minute
delay in LSOM the red trip
LED will be on.
1
Compressor protector is open.
2
Outdoor unit power disconnect is open.
3
Compressor circuit breaker or fuse(s) is open.
4
Broken wire or connector is not making contact.
5
Low pressure switch open if present in the system.
6
Compressor contactor has failed to close.
Red Trip and Yellow
Alert LEDs Flashing
Simultaneous flashing.
Indicates that the control circuit voltage is too low for operation.
Yellow Alert Flash
Code 1*
Long Run Time
− Compres-
sor is running extremely
long run cycles
1
Low refrigerant charge.
2
Evaporator blower is not running.
3
Evaporator coil is frozen.
4
Faulty metering device.
5
Condenser coil is dirty
.
6
Liquid line restriction (filter drier blocked if present)
.
7
Thermostat is malfunctioning
.
Yellow Alert Flash
Code 2*
System Pressure Trip
−
Discharge or vapor pressure
out of limits or compressor
overloaded
1
Check high head pressure or discharge line sensor.
2
Condenser coil poor air circulation (dirty, blocked, damaged).
3
Condenser fan is not running.
4
Return air duct has substantial leakage.
5
If low pressure switch is present, see Flash Code 1 information.
Yellow Alert Flash
Code 3*
Short Cycling
− Compres-
sor is running only briefly
1
Thermostat demand signal is intermittent.
2
Time delay relay or DCB is defective.
3
If high pressure switch is present, see Flash Code 2 information.
4
If low pressure switch is present, see Flash Code 2 information.
Yellow Alert Flash
Code 4*
Locked Rotor
1
Run capacitor has failed.
2
Low line voltage (contact utility if voltage at disconnect is low).
3
Excessive liquid refrigerant in the compressor.
4
Compressor bearings are seized.
Yellow Alert Flash
Code 5*
Open Circuit
1
Outdoor unit power disconnect is open.
2
Unit circuit breaker or fuse(s) is open.
3
Unit contactor has failed to close.
4
High pressure switch is open and requires manual reset.
5
Open circuit in compressor supply wiring or connections.
6
Unusually long compressor protector reset time due to extreme ambient temperature.
7
Compressor windings are damaged.
Yellow Alert Flash
Code 6*
Open Start Circuit
− Cur-
rent only in run circuit
1
Run capacitor has failed.
2
Open circuit in compressor start wiring or connections.
3
Compressor start winding is damaged.
Yellow Alert Flash
Code 7*
Open Run Circuit
− Current
only in start circuit
1
Open circuit in compressor start wiring or connections.
2
Compressor start winding is damaged.
Yellow Alert Flash
Code 8*
Welded Contactor
−
Compressor always runs
1
Compressor contactor failed to open.
2
Thermostat demand signal not connected to LSOM.
Yellow Alert Flash
Code 9*
Low Voltage
− Control cir-
cuit <17VAC
1
Control circuit transformer is overloaded
.
2
Low line voltage (contact utility if voltage at disconnect is low).
*Flash code number corresponds to a number of LED flashes, followed by a pause, and then repeated. Reset ALERT flash code by removing 24VAC power
from LSOM; last code will display for 1 minute after LSOM is powered on.
Note: If the unit is equipped with a two−stagged compressor, upon Y2 signal detection and after five seconds, the LSOM will send 24 VAC to the solenoid.
Once the solenoid is fully energized, the LSOM reduces voltage to between 4 to 18 VDC . Every 15 minutes the solenoid voltage will be increase to 24 volts
for a few seconds to ensure solenoid valve is engaged until Y2 signal is no longer present.
