Carrier 62E ERV Troubleshooting, Symptom Possible Causes Action to Check Possible Remedy

TROUBLESHOOTING

See Table 13 for troubleshooting information.

Table 13 — ERV Troubleshooting

SYMPTOM	POSSIBLE CAUSES	ACTION TO CHECK	POSSIBLE REMEDY
	Disconnect switch is in the off	Verify that the disconnect switch is	Move the disconnect lever to the 'ON'
	position	in the 'ON' position	position.
			Using a volt meter verify that the voltage
	No power to the ERV	Check for power at the disconnect	being supplied to the ERV matches the ERV's
		switch	operating voltage. If the ERV operates on
			three phase power check all three legs.
ERV will not turn on			Using a volt meter verify that the voltage on
	One or more blown fuses	Check for power at the bottom of	the bottom side of the fuse block matches the
		the fuse block	ERV's operating voltage. If the ERV operates
			on three phase power check all three legs.
	Control board transformer circuit	Look at the small transformer next
		to the control circuit board to see if	Depress the circuit breaker back in.
	breaker is tripped
		the black circuit pushed out
	The fan speed / CFM level is set	Use the user interface push button	Adjust the fan speed / CFM demand levels by
		to view the 'Outside Air' and	pressing the user interface push button and
	too low
		'Exhaust Air' settings	turning the adjust knob.
			Using a volt meter verify that the voltage on
	One or more blown fuses	Check for power at the bottom of	the bottom side of the fuse block matches the
		the fuse block	ERV's operating voltage. If the ERV operates
			on three phase power check all three legs.
	Rooftop Economizer Option (if		Using a continuity meter check for continuity
		Check for continuity across the	across the two wires that connect to the mer-
ERV is running but	equipped) has shut down the ERV
		mercury switch on the economizer	cury switch on the economizer damper. If the
blowers will not turn	because the rooftop unit is in 'Free	damper.	contacts are open, the rooftop unit is in 'Free
	Cooling' mode		Cooling'.
	Smoke Detector Option (if		Using the wiring schematics verify that the
	equipped) has shut down the ERV
		Check for wiring errors.	smoke detector is wired to the control board
	because it is sensing smoke in the		properly.
	exhaust airstream on the ERV.
		Check to see if the outside temper-	Use a thermometer to measure the outside
	Low Temperature Lockout Option		temperature. Use the wiring schematics to
	(if equipped)	ature is above –30 F	verify that temperature probe on the intake air
		(–34.4 C). Check for wiring errors
			side of the ERV is wired properly.
	The fan speed / CFM level is set	Use the user interface push button	Adjust the fan speed / CFM demand levels by
		to view the 'Outside Air' and	pressing the user interface push button and
	too low
		'Exhaust Air' settings	turning the adjust knob.
	Rooftop Economizer with Power		Using a continuity meter check for continuity
	Relief Option (if equipped) has	Check for continuity across the	across the two wires that connect to the mer-
	shut down the supply blower	mercury switch on the economizer	cury switch on the economizer damper. If the
Only one of the two	because the rooftop unit is in 'Free	damper	contacts are open, the rooftop unit is in 'Free
blowers is turning	Cooling' mode		Cooling'.
	One of the blowers is wired		Using the wiring schematics verify that both
		Check for wiring errors.	the power wires and the control wires are con-
	incorrectly
			nect properly.
	The ERV Standard Frost Protec-
	tion Option has turned off the sup-	Check for frost on the wheel.	Wait for Defrost mode to finish.
	ply blower to defrost the wheel
	The ERV Enthalpy Control, Dry
	bulb Control / Wheel Bypass Stop /	Check for Stop / Jog movement of	Wait until sequence is completed.
	Jog Option (if equipped) is	wheel.
	activated
		Check to see if the connector
	The wheel motor is unplugged.	between the wheel motor and the	Plug the two connectors together.
		cabinet wiring is securely
Blowers are on but		connected.
	The wheel motor is wired		Compare the wheel motor, control board and
the wheel is not		Check for wiring errors.
	incorrectly.		relay are wired correctly.
turning
	The wheel belt is off or broken	Check the wheel belt.	Verify that the wheel belt is seated in the pul-
			ley and on the rim of the wheel.
			Carefully rotate the wheel by grabbing the
			outer rim and spinnig the wheel. After letting
	The air seals on the wheel are too	Check to see if the wheel spins	go the wheel should continue to spin for three
	tight	freely.	to four seconds. Should the air seals need
			adjusting see the maintainence section of this
			book.

Copyright 2010 Carrier Corporation

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.

Catalog No. 04-53620007-01 Printed in U.S.A. Form 62E-C1SI Pg 38 8-10 Replaces: New