21
1.800.627.4499
HE-Series Indoor
ERV
INSTALLATION
5.6 EXTERNAL CONTROL CONNECTIONS
5.6.1 Single 2-Wire Control, Unpowered
Use the schematic shown in Figure 5.6.0 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
Connect the blue lead to one yellow lead.
u
Connect the control’s contacts to the red lead and the remaining yellow lead.
Control on separate Power Supply, no power present at Control Output:
Wire as shown for the Single 2-wire control.
FIGURE 5.6.0 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
5.6.2 Control Sending 24 VAC “On” Signal
Use the schematic shown in Figure 5.6.1 if a 24 VAC “On” signal is to be sent from an external
power source to the ERV.
u
Make sure the blue and red leads are separately capped and not connected to any other
wires.
Now you safely can apply 24 VAC to the two yellow leads to operate the ERV’s isolation relay.
Supply only 24 VAC (not
VDC) from a Class II Power
Source.
CAUTION
FIGURE 5.6.1 24 VAC FROM AN EXTERNAL SOURCE
Unit 24VAC
Power Supply
Cap Blue and Red Leads when using
24VAC from external source.
C
UNIT INTERNAL CONTROL WIRING
(SIMPLIFIED)
24VAC FROM AN EXTERNAL SOURCE
Isolation
Relay Coil
Image 3 from filename Control Connections EV450-HE1XIN_DEC14
KMC 12/11/14
RED
YEL
YEL
BLUE
Unit 24VAC
Power Supply
Connect Blue & First Yellow Leads
Connect Switch between Red &
Second Yellow Leads
UNIT INTERNAL CONTROL WIRING
C
Isolation
Relay Coil
(SIMPLIFIED)
A SWITCH OR NON-POWERED
CONTROL USING UNIT'S 24VAC POWER
SUPPLY
Image 1 from filename Control Connections EV450-HE1XIN_DEC14
KMC 12/11/14
BLUE
YEL
YEL
RED
5.6.3 Control System with two Non-Powered Relay Contacts:
ERVs with Independent Blower Control Only:
Use Figure 5.6.2 if the external control system provides no voltage or current at its output
contacts.
u
Connect the two blue leads together.
u
Connect the red lead to one side of each of the output contacts.
u
Connect the other side of the output contacts to the appropriate yellow leads: marked “FA
Blower” and “EA Blower.”
FIGURE 5.6.2 TWO EXTERNAL NON-POWERED RELAY CONTACTS
RED
Isolation Relay Coils
(FA Blower)
(EA Blower)
BLUE
YEL
BLUE
UNIT INTERNAL WIRING
YEL
Non-Powered Relay Contacts Connected
between Red Lead and Yellow Leads
Connect 1st & 2nd Blue Leads
Unit 24VAC
Power Supply
C
C
TWO EXTERNAL NON-POWERED RELAY
CONTACTS
Image 4 from filename Control Connections EV450-HE1XIN_DEC14
KMC 12/11/14
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.
