Carrier PSV, PSD006-070, 50PSH instruction manual ECM Troubleshooting, Fault Description Solution

IMPORTANT: Always recover the refrigerant from the system with suitable approved tools, recovery equipment, and practices prior to attempting to remove or repair any TXV.

IMPORTANT: Due to the hygroscopic nature of the POE oil in Puron refrigerant (R-410A) and other environ- mentally sound refrigerants, any component replace- ment must be conducted in a timely manner using caution and proper service procedure for these types of refrigerants. A complete installation instruction will be included with each replacement TXV/filter drier assem- bly. It is of critical importance these instructions are carefully understood and followed. Failure to follow these instructions can result in a system that is contami- nated with moisture to the extent that several filter drier replacements may be required to properly dry the system.

IMPORTANT: Repair of any sealed refrigerant system requires training in the use of refrigeration tools and proce- dures. Repair should only be attempted by a qualified ser- vice technician. A universal refrigerant handling certificate will be required. Local and/or state license or certificate may also be required.

See Tables 37-39 for additional troubleshooting information.

CAUTION

Disconnect power from unit before removing or replacing connectors, or servicing motor. Wait 5 minutes after dis- connecting power before opening motor.

Table 37 — ECM Troubleshooting

FAULT	DESCRIPTION	SOLUTION
Motor rocks slightly when		This is normal start-up for ECM.
starting
Motor will not start	No movement	Check power at motor.
		Check low voltage (24-vac R to C) at motor.
		Check low voltage connections (G,Y, W, R, C) at motor.
		Check for unseated pins in connectors on motor harness. See Fig. 40.
		Test with a temporary jumper between R and G.
		Check motor for tight shaft.
		Perform motor/control replacement check.
		Run moisture check. See Moisture Check section in Troubleshooting.
	Motor rocks	Check for loose or non-compliant motor mount.
		Make sure blower wheel is tight on shaft.
		Perform motor/control replacement check.
Motor oscillates up and down		It is normal for motor to oscillate with no load on shaft.
while being tested off of blower
Motor starts, but runs erratically	Varies up and down or intermittent	Check line voltage for variation or “sag.”
		Check low voltage connections (G,Y, W, R, C) at motor, unseated pins in motor harness
		connectors. See Fig. 40.
		Check “Bk” for erratic cfm command (in variable speed applications).
		Check system controls, thermostat.
		Perform moisture check. See Moisture Check section in Troubleshooting.
	“Hunts” or “puffs” at high cfm	If removing panel or filter reduces “puffing,” reduce restriction or reduce maximum airflow.
	(speed)
	Stays at low cfm despite system	Check low voltage (thermostat) wires and connections.
	call for cool or heat cfm
		Verify fan is not in delay mode. Wait until delay is complete.
		Check to see if “R” is missing/not connected at motor.
		Perform motor/control replacement check.
	Stays at high cfm	Check to see if “R” is missing/not connected at motor.
		Verify fan is not in delay mode. Wait until delay is complete.
		Perform motor/control replacement check.
	Blower will not shut off	Check to see if there is current leakage from controls into G, Y, or W. Check for Triac switched
		thermostat or solid state relay.
Excessive noise	Noisy blower or cabinet	Determine if it is air, cabinet, duct, or motor noise.
		Check for loose blower housing, panels, etc.
		If high static is creating high blower speed, check for air whistling through seams in ducts,
		cabinets, or panels.
		If high static is creating high blower speed, check for cabinet/duct deformation.
	“Hunts” or “puffs” at high cfm	If removing panel or filter reduces “puffing,” reduce restriction or reduce maximum airflow.
	(speed)
Evidence of moisture	Motor failure or malfunction has	Replace motor and perform moisture check. See Moisture Check section in Troubleshooting.
	occurred and moisture is present
	Evidence of moisture present	Perform moisture check. See Moisture Check section in Troubleshooting.
	inside air mover

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