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EV-Series Indoor
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
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:
u
Wire as shown for the Single 2-wire control.
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 on the previous page.
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 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.
FIGURE 5.5.1 24 VAC FROM AN EXTERNAL SOURCE
Supply only 24 VAC (not
VDC) from a Class II Power
Source.
CAUTION
5.5.3 Control Operating on Unit’s 24 VAC Power Supply
Use the schematic shown in Figure 5.5.2 if controls are operating on unit’s 24 VAC power
supply.
u
24 VAC power is available at the blue and red leads.
u
Connect one of the yellow leads to the blue lead.
u
Connect the switched output of the Control to the red lead to operate the ERV’s isolation
relay.
FIGURE 5.5.2 AN EXTERNAL CONTROL DEVICE USING UNIT’S 24 VAC POWER SUPPLY
External control system
should not draw more than
8 VA.
CAUTION
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
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
Connect Blue & First Yellow Leads
Connect Control's N.O. Output to 2nd Yellow Lead
External Control is
powered by 24VAC
available between the Red
and Blue leads.
8VA Maximum Load.
Unit 24VAC
Power Supply
C
UNIT INTERNAL CONTROL WIRING
(SIMPLIFIED)
AN EXTERNAL CONTROL DEVICE USING
UNIT'S 24VAC POWER SUPPLY
Isolation
Relay Coil
M
PU
Image 2 from filename Control Connections EV450-HE1XIN_DEC14
KMC 12/11/14
BLUE
YEL
YEL
RED