Emerson Copeland Scroll UltraTech CoreSense Application Engineering Bulletin page 11

Yellow "ALERT"
Locked Rotor
Flash Code 4
Yellow "ALERT" Compressor (Moderate Run)
Flash Code 5 Trip
Yellow "ALERT" Welded Contactor
Flash Code 8 Compressor always runs
Yellow "ALERT" Low Supply Voltage
Flash Code 9 Voltage below 18V
Compressor (Pressure) Trip
Red "LOCKOUT"
Compressor is locked out
Flash Code 2
after 4 consecutive or 10 total
Yellow Off
compressor (pressure) trip events
Pressure Switch Cycling
Red "LOCKOUT"
Compressor is locked out after 4
Flash Code 3
consecutive or 10 total pressure
Yellow Off
cycling events
Red "LOCKOUT" Locked Rotor
Flash Code 4 Compressor is locked out after 10
Yellow Off consecutive locked rotor events
© 2015 Emerson Climate Technologies
Table 2 Continued
1. Run capacitor has failed
2. Low line voltage (contact utility if voltage at disconnect is low)
• Check wiring connections
3. Excessive liquid refrigerant in compressor
4. Compressor bearings are seized
• Measure compressor oil level
1. Evaporator blower is not running
• Check blower relay coil and contacts
• Check blower motor capacitor
• Check blower motor for failure or blockage
• Check evaporator blower wiring and connectors
• Check indoor blower control board
• Check thermostat wiring for open circuit
2. Faulty metering device
• Check TXV bulb installation (size, location and contact)
• Check if TXV/fixed orifice is stuck closed or defective
3. Condenser coil poor air circulation (dirty, blocked, damaged)
4. Low refrigerant charge
1. Compressor contactor has failed closed
2. Thermostat demand signal not connected to module
1. Control Circuit transformer is overloaded
2. Low line voltage (contact utility if voltage at disconnect is low)
"LOCKOUT" Flash Codes
1. Condenser fan is not running
• Check fan capacitor
• Check fan wiring and connectors
• Check fan motor for failure or blockage
2. High head pressure
• Check high pressure switch if present in system
• Check if system is overcharged with refrigerant
• Check for non-condensable in system
3. Condenser coil poor air circulation (dirty, blocked, damaged)
4. Return air duct has substantial leakage
1. Time delay relay or control board defective
2. If high pressure switch present go to Flash Code 2 information
1. Run capacitor has failed
2. Low line voltage (contact utility if voltage at disconnect is low
• Check wiring connections
3. Excessive liquid refrigerant in compressor
4. Compressor bearings are seized
• Measure compressor oil level
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AE8-1385 R1