23
1.800.627.4499
HE-Series Outdoor
ERV
INSTALLATION
5.5 EXTERNAL CONTROL CONNECTIONS
5.5.1 Single 2-Wire Control, Unpowered
Use the schematic shown in Figure 5.5.0 if the control requires no power to operate and acts
like a simple on/off switch. The control must not supply any power to the ERV unit.
u
Install jumper (provided) between terminals 2 and 3.
u
Connect the control’s contacts to terminals 1 and 4 to operate the ERV’s isolation relay.
Control on separate Power Supply, no power present at Control Output:
Wire as shown for the Single 2-wire control.
FIGURE 5.5.0 A SWITCH OR NON-POWERED CONTROL USING UNIT'S 24 VAC POWER SUPPLY
Make sure the control pro-
vides no voltage or current
at its output terminals.
CAUTION
5.5.2 Control Sending 24 VAC “On” Signal
Use the schematic shown in Figure 5.5.1 if a 24 VAC “On” signal is to be sent from an external
power source to the ERV.
u
Make sure jumper is NOT installed between Terminals 2 and 3.
Now you safely can apply 24 VAC to the Terminals 3 and 4 to operate the ERV’s isolation relay.
FIGURE 5.5.1 24 VAC FROM AN EXTERNAL SOURCE
Supply only 24 VAC (not
VDC) from a Class II Power
Source.
CAUTION
UNIT INTERNAL CONTROL WIRING
C
Isolation
Relay Coil
(SIMPLIFIED)
24VAC FROM AN EXTERNAL SOURCE
1
2
3
4
5
Unit's 24VAC
Power Supply
Image C from Filename: Control Connections HE1XRT and larger
5-5-2011.dwg
Friedlander
5/5/2011
Connect Terminals 2 & 3
Connect Switch between Terminals 1 & 4
UNIT INTERNAL CONTROL WIRING
C
Isolation
Relay Coil
(SIMPLIFIED)
A SWITCH OR NON-POWERED
CONTROL USING UNIT'S 24VAC POWER
SUPPLY
1
2
3
4
5
Unit's 24VAC
Power Supply
Image A from Filename: Control Connections HE1XRT and larger
5-5-2011.dwg
Friedlander
5/5/2011
5.5.3 Control System with two Non-Powered Relay Contacts:
ERVs with Independent Blower Control Only:
Use Figure 5.5.2 if the external control system provides no voltage or current at its output
contacts.
u
Install jumper (provided) between terminals 2 and 3.
u
Connect one side of each of the output contacts to Terminal 1.
u
Connect the other side of the output contacts to the appropriate yellow leads: Terminal 4 for
the “FA Blower,” and Terminal 5 for the “EA Blower.”
FIGURE 5.5.2 TWO EXTERNAL NON-POWERED RELAY CONTACTS
Connect Terminals 2 & 3
UNIT INTERNAL CONTROL WIRING
C
Isolation Relay Coil (Fresh Air)
(SIMPLIFIED)
A SWITCH OR NON-POWERED
CONTROL USING UNIT'S 24VAC POWER
SUPPLY
1
2
3
4
5
Unit's 24VAC
Power Supply
C
Isolation Relay Coil (Exhaust Air)
Image B from Filename: Control Connections HE1XRT and larger
5-5-2011.dwg
Friedlander
5/5/2011
NOTE: The sim-
plified schematics
below show only
the relevant portions of
the low-voltage control
circuit in the ERV unit and
representational external
control approaches. See
the complete unit schemat-
ics above.
