Lifebreath 700FD/DD, 850FD/DD, 500ERV, 1200ERV Electrical Connections, Self Test of Defrost Systems

Electrical Connections

It is recommended that a licensed electrician make all electrical connections. It is very important that the unit be properly grounded. It is recommended that a separate 15 amp/120 volt circuit be used.

WARNING: In order to prevent electric shock when cleaning or servicing the HRV/ERV, it is extremely important to confirm the polarity of the power line that is switched by the safety (disconnect) switch whose control arm is located on the outside of the electrical control box area. The hot line (black) is the proper line to be switched. To confirm the proper polarity, use a voltmeter or test lamp to make sure there is no power after the switch when the door is open. Check between that point and ground (on the cabinet). This must be done as occasionally some buildings are improperly wired. Always make sure the HRV/ERV is properly grounded.

	Black	Power Supply
	Line
		Cord
	White
Black	Neut.
	Power
	Terminal
	Block.
		GND.
Electrical Connection

FAN DEFROST

Models 700FD, 850FD, 1200FD

Fan defrost HRV’s are equipped with an electronically controlled fan defrost system to remove frost that collects on the warm air side of the aluminum heat transfer surfaces of the heat exchanger core. When the outside air temperature drops below 27˚F(-3˚C), defrost is activated which provides for an automatic defrost cycle. During the automatic defrost cycle the fresh air supply is shut off while the exhaust fan contin ues to operate. This allows warm inside air to flow through the heat exchanger core melting frost

accumulation. After the defrost period, the fresh air supply fan automatically returns to the normal speed and fresh outside air continues to be drawn into the building. Water from the melted frost collects in the bottom drip pans and drains out through the bottom drain connections. The defrost cycle repeats automatically until the air temperature rises above 27˚F(-3˚C).

DAMPER DEFROST

Models 700DD, 850DD, 1200DD

These damper defrost HRV’s have an electronically controlled damper defrost mechanism. If the outside temperature drops below 27˚F(-3˚C ), the defrost timer is activated. A motor driven damper door mechanism opens the defrost port and at the same time closes off the supply air from outside. After approximately 3 minutes, the damper operates in the opposite direction to close off the defrost port and reopen the fresh air at the supply port. The 27.5 minute wait time and 3 minute defrost cycle repeat until the temperature again rises above 27˚F (-3˚C).

Self Test of Defrost Systems

Models 700, 850, 1200

If confirmation of the defrost system is needed, complete the following steps.

1.Disconnect power to the unit and open access/ maintenance doors.

2.Locate the “snap disc” type temperature sensor mounted in the upper left hand corner (cold air stream) of the HRV.

3.Disconnect the two wires from the HRV to the sensor, at the sensor.

4.Using a jump wire with alligator clips, join two wires from the HRV together.

5.Close access doors and power the unit.

This procedure will simulate a defrost that would occur automatically in the field when the outside temperature drops below -3˚C (27˚F).

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