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Lockout mode
The timer can be set to lockout mode (timers disabled) as
follows: press and hold SELECT for 5 seconds; then the
high−speed status light will flash; then release the button.
The timer is now in lockout mode. If SELECT is pressed
during lockout mode, the high−speed status light will mo-
mentarily illuminate but no override will be initiated.
If lockout mode is initiated when the timer is activated, the
timer will continue it’s timed sequence but will not allow any
further overrides to be initiated. To unlock lockout mode,
press and holding SELECT for five seconds; then the high−
speed status light will stop flashing; release the button. The
timer will now operate normally.
Installing mechanical timers
The mechanical timer is a two−wire dry contact" timer. A
jumper wire must be connected between ON and RED.
Connect the 2 timers wires to ON and HI (see figure 23).
1
2
3
4
5
6
7
8
9
10
LOW
ON
ED
R
YEL
GRN
HI
COM
NO
NC
BLK
Connect the 2 wires from the timer
to ON and HI on the terminal block
2 wire timers
require a jumper
between ON and
RED on the
terminal block
OFF
10
20
40
30
50
60
Caution: Low Voltage Only
Figure 23. Mechanical Timer Installation
Interlocking the HRV/ERV Blower to Air Handler/Furnace Blower
Connecting the HRV/ERV unit as illustrated will ensure the
air handler/furnace blower motor is operating whenever
the HRV/ERV blower is ventilating.
The HRV/ERV unit must be interlocked to the furnace/air
handler with a simplified (return/return) installation and
should be interlocked with a partially dedicated installation
(see figure 24).
CAUTION
Potential equipment malfunction or damage.
May require repairs and/or void warranty.
When interconnecting HRV/ERV ductwork with
HVAC duct system, HRV/ERV blower must be inter-
locked with HVAC blower. System air circulation
must not be allowed to backflow through HRV/ERV.
1
2
3
4
5
6
7
8
9
10
LOW
ON
ED
R
YEL
GRN
HI
COM
NO
NC
BLK
R
Thermostat
Furnace
G W
Y C
R G W Y
Wire
connection
Caution: Low Voltage Only
Figure 24. Interlocking HRV/ERV Unit Blower to
the Air Handler/Furnace Blower
Electrical Connections
Plug the HRV/ERV directly into a standard designated
120VAC electrical outlet. Use of an extension cord is NOT
RECOMMENDED for this appliance.
If further wiring is required, then a licensed electrician
should make all electrical connections. It is recommended
that a separate 15 amp/120 volt circuit be used.
Figures 25 thru 27 (Page 25 thru Page 27) show wiring
diagrams for the units described in this manual.
WARNING
Electric Shock Hazard
Can cause injury or death.
Confirm the polarity of the 120 Volt supply source at the receptacle for the HRV/ERV device. The door safety
switch of the HRV/ERV can cause an electrical shock hazard if the polarity is not properly wired. The grounding
means of the HRV/ERV device should also be confirmed.
The proper polarity and ground can be checked at the receptacle using a 3−prong plug device called a ’polarity
tester’. Another method to check for proper polarity is to use a volt−ohm meter to check for voltage from hot
(black) to ground (chassis) at the HRV/ERV.
