Emerson AE8-1385 Application Engineering, B U L L E, Status, Description, “ALERT” Flash Codes

Application Engineering
B U L L E	T	I	N	AE8-1385

Table 2 – CoreSense Diagnostics LED Troubleshooting Information

Flash Code number corresponds to the number of LED flashes, followed by a pause and then repeated.

TRIP and ALERT LEDs flashing at same time means control circuit voltage is too low for operation (brown-out conditions).

Status	Description			Troubleshooting Information
Solid Green “RUN”	Module has power and	Supply voltage is present at module terminals
	operating normally
		1.	Compressor protector is open
			•	Check for high head pressure
	Thermostat demand signal Y is		•	Check compressor supply voltage
		2.	Outdoor unit power disconnect is open
Solid Red “TRIP”	present, but the compressor is
		3.	Compressor circuit breaker or fuse(s) is open
	not running
		4.	Broken wire or connector is not making contact
		5.	High pressure switch open if present in system
		6.	Compressor contactor has failed open

“ALERT” Flash Codes

1.Low refrigerant charge

2.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

	Long Run Time	3. Evaporator coil is frozen
Yellow “ALERT”	Low Refrigerant Charge	• Check for low suction pressure
Flash Code 1	Compressor is running extremely	•	Check for excessively low thermostat setting
	long run cycles	•	Check evaporator airflow (coil blockages or return air filter)

•Check ductwork or registers for blockage

4.Faulty metering device

•Check TXV bulb installation (size, location and contact)

•Check if TXV/fixed orifice is stuck closed or defective

5.Liquid line restriction (filter drier blocked if present in system)

6.Thermostat is malfunctioning

•Check thermostat sub-base or wiring for short circuit

•Check thermostat installation (location, level)

1.Condenser fan is not running

•Check fan capacitor

•Check fan wiring and connectors

	Compressor (Pressure) Trip	• Check fan motor for failure or blockage
Yellow “ALERT”	High Refrigerant Charge	2. High head pressure
Flash Code 2	Discharge pressure out of limits	•	Check high pressure switch if present in system
	or compressor overloaded	•	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

	Pressure Switch Cycling	1.	Time delay relay or control board defective
Yellow “ALERT”	Compressor is running only
Flash Code 3	briefly due to pressure switch	2.	If high pressure switch present go to Flash Code 2 information
	cycling

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Printed in the U.S.A.