16
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, 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 is properly grounded.
DAMPER DEFROST
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).
Automatic Self Test of Defrost
Systems
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).
Black
Black
White
Power Supply
Cord
Line
GND.
Green
Neut.
Power
Terminal
Block.
Electrical Connection
Summary of Contents for 1000RHC
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