EV450RT
Due to continuing product development, specifications are subject to change without notice.
© 2014 RenewAire LLC
138060_009 EV450RTMan_Feb14.indd Revised 02/2014 www.renewaire.com
Page 8
Control Wiring Schematics
NOTE:
The simplified 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 schematics elsewhere in this manual.
OBSERVE THESE LIMITS TO WIRE LENGTH AND GAUGE,
in order to ensure reliable operation of the control system.
Wire Gauge
#22
#20
#18
#16
#14
#12
Circuit Length
100’
150’
250’
400’
700’
1000’
“Circuit Length” is distance from ERV to Control Device.
How to Reset the 24VAC Circuit Breaker
If the transformer is subjected to an excessive load or a short
circuit, the circuit breaker will trip to prevent the failure of the
transformer. When it trips the circuit breaker’s button pops up.
Shut off the primary-side power to the unit, and remove the
excessive load or the short. The circuit breaker can be reset
about fifteen seconds after it trips by pressing in the button.
NOTE:
INSTALLING CONTRACTOR:
If primary-side voltage is 230VAC, move black primary-side lead
from transformer’s “208V” terminal to the transformer’s terminal
marked “240V” (“230V” in some units).
Do not move the black primary-side lead that is connected to the
transformer’s “COM” terminal.
Limits of Power Output
If limits on wire gauge and length are observed, you may connect
control devices that draw up to 8VA to the blue and red wires.
More than one device can be connected as long as total steady-
state load does not exceed 8VA.
Control Options
PN 165840_000 HE1XIN P1
C
GND
L1 L2
Contactor
Motor
(FA)
Motor
(EA)
Class 2
Transformer with
Circuit Breaker
POWER SUPPLY
SINGLE-PHASE 60hz
See Unit Nameplate for VOLTAGE
Fuse Block
(factory option)
RED
Isolation Relay
BLUE
YEL
YEL
RED
BLUE
YEL
YEL
Unit 24VAC
Power Supply
Connect Blue & First Yellow Leads
Connect Switch between Red &
Second Yellow Leads
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 INTERNAL CONTROL WIRING
C
Isolation
Relay Coil
RED
BLUE
YEL
YEL
Unit 24VAC
Power Supply
Cap Blue and Red Leads when using
24VAC from external source.
C
RED
BLUE
YEL
YEL
Unit 24VAC
Power Supply
C
(SIMPLIFIED)
UNIT INTERNAL CONTROL WIRING
(SIMPLIFIED)
UNIT INTERNAL CONTROL WIRING
(SIMPLIFIED)
UNIT CONTROL WIRING SHOWN
SHOWN IN CONTROL OPTIONS AT LEFT
UNIT WIRING
A SWITCH OR NON-POWERED
CONTROL USING UNIT'S 24VAC POWER
SUPPLY
AN EXTERNAL CONTROL DEVICE USING
UNIT'S 24VAC POWER SUPPLY
24VAC FROM AN EXTERNAL SOURCE
Isolation
Relay Coil
Isolation
Relay Coil
MPU
B.
Control Sending 24VAC “On” Signal (from an external
power source) to ERV:
Make sure jumper is NOT installed
between Terminals 2 & 3. Now you safely can apply 24VAC to
the Terminals 3 & 4 to operate the ERV’s isolation relay.
C.
Control operating on Unit’s 24VAC Power Supply:
24VAC
power is available at the Terminals 1 & 2. CAUTION: external
control system should not draw more than 8VA. Install jumper
(provided) between terminals 2 & 3. Connect the switched
output of the Control to Terminal 4 to operate the ERV’s
isolation relay.
Control Options
PN 165840_000 HE1XIN P1
C
GND
L1 L2
Contactor
Motor
(FA)
Motor
(EA)
Class 2
Transformer with
Circuit Breaker
POWER SUPPLY
SINGLE-PHASE 60hz
See Unit Nameplate for VOLTAGE
Fuse Block
(factory option)
RED
Isolation Relay
BLUE
YEL
YEL
RED
BLUE
YEL
YEL
Unit 24VAC
Power Supply
Connect Blue & First Yellow Leads
Connect Switch between Red &
Second Yellow Leads
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 INTERNAL CONTROL WIRING
C
Isolation
Relay Coil
RED
BLUE
YEL
YEL
Unit 24VAC
Power Supply
Cap Blue and Red Leads when using
24VAC from external source.
C
RED
BLUE
YEL
YEL
Unit 24VAC
Power Supply
C
(SIMPLIFIED)
UNIT INTERNAL CONTROL WIRING
(SIMPLIFIED)
UNIT INTERNAL CONTROL WIRING
(SIMPLIFIED)
UNIT CONTROL WIRING SHOWN
SHOWN IN CONTROL OPTIONS AT LEFT
UNIT WIRING
A SWITCH OR NON-POWERED
CONTROL USING UNIT'S 24VAC POWER
SUPPLY
AN EXTERNAL CONTROL DEVICE USING
UNIT'S 24VAC POWER SUPPLY
24VAC FROM AN EXTERNAL SOURCE
Isolation
Relay Coil
Isolation
Relay Coil
MPU
Control Options
PN 165840_000 HE1XIN P1
C
GND
L1 L2
Contactor
Motor
(FA)
Motor
(EA)
Class 2
Transformer with
Circuit Breaker
POWER SUPPLY
SINGLE-PHASE 60hz
See Unit Nameplate for VOLTAGE
Fuse Block
(factory option)
RED
Isolation Relay
BLUE
YEL
YEL
RED
BLUE
YEL
YEL
Unit 24VAC
Power Supply
Connect Blue & First Yellow Leads
Connect Switch between Red &
Second Yellow Leads
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 INTERNAL CONTROL WIRING
C
Isolation
Relay Coil
RED
BLUE
YEL
YEL
Unit 24VAC
Power Supply
Cap Blue and Red Leads when using
24VAC from external source.
C
RED
BLUE
YEL
YEL
Unit 24VAC
Power Supply
C
(SIMPLIFIED)
UNIT INTERNAL CONTROL WIRING
(SIMPLIFIED)
UNIT INTERNAL CONTROL WIRING
(SIMPLIFIED)
UNIT CONTROL WIRING SHOWN
SHOWN IN CONTROL OPTIONS AT LEFT
UNIT WIRING
A SWITCH OR NON-POWERED
CONTROL USING UNIT'S 24VAC POWER
SUPPLY
AN EXTERNAL CONTROL DEVICE USING
UNIT'S 24VAC POWER SUPPLY
24VAC FROM AN EXTERNAL SOURCE
Isolation
Relay Coil
Isolation
Relay Coil
MPU
This ERV is provided with a Class II 24VAC power supply system that
operates the unit’s contactor(s) for EV450 and HE1X. The ERV’s
24VAC Power Supply can also be used to power the externally-
installed controls system: up to 8VA of power is available.
The unit’s power supply system includes isolation relay(s) so you
can use external controls whose contact ratings are as low as 50mA
(1.2VA). Also, it is possible to operate the isolation relays with 24VAC
power from an external source (with proper wiring connections).
A built-in circuit-breaker prevents damage to the transformer and other
low-voltage components in the event of a short-circuit or overload. In
extreme cases, the transformer itself is designed to fail safely.
24VAC Power Supply
Provided with this ERV Unit
1. Connect only to components intended for use with 24VAC
power.
2. Do not undersize the low-voltage wires connected to
this device. Observe the wire length and gauge limits
indicated in this manual.
3. Do not overload this unit’s 24VAC power supply system.
Confirm that the power requirements of devices you connect
to this power supply system do not exceed 8VA in total.
4. If an external source of 24VAC power is used to control
the unit, consult the wiring schematics and connect the
external power only to the specified terminals in order
to avoid damaging the unit or external controls. Connect
only CLASS II power to the control terminals of this unit.
5. Unit is not equipped to receive analog signals (such as
1-10vdc or 4-20mA).
6. Unit is not equipped to communicate directly with
Building Management Systems (such as BACNET,
LONWORKS, etc.). However, the unit can be controlled
by powered or non-powered contacts operated by any
kind of control system.
Specifications
•
Nominal Output Voltage under load: 24VAC
•
Typical Output Voltage at no load:
29-31V
•
Minimum contact rating
for connected control device:
(50mA (1.2VA)
•
Circuit Breaker Trip Point:
3A
Make sure the control provides no voltage or current at its
output terminals.
Supply only 24VAC (not VDC) from a Class II Power Source.
Be careful if the external control system provides 24VAC
power at its control output: make sure blue and red leads are
separately capped and not connected to any other wires.
A.
Single 2-wire Control:
Use schematic below 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.
Install jumper (provided) between terminals 2 & 3.
Connect the control’s contacts to terminals 1 & 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.
