Specifications
VCES-ERV-IOM-1A – ERV500i/e
23
Remote Fan Control
Remote fan control can be achieved by connecting dry
contact controls to the terminal interface at terminals
labeled: Low-Com-High (not all units have two speeds).
Placing a jumper across the Low and Com terminals will
put the unit in low speed ventilation or placing a jumper
across the High and Com terminals will put the unit into
high speed. Do not jumper all three terminals together.
These controls could also be the following: SPDT switch,
dehumidistat, CO
2
sensor, light sensor, heat sensor, timer,
Building Management System, etc. Figure G5 represents a
switch connected to the unit.
Low Temperature Control
The fans of the ERV can be controlled using a setpoint low
temperature controller. If the supply air discharge tem-
perature falls below the setpoint on the low temperature
controller, the contacts between R–W break, therefore,
de-energizing the fans and closing the outside air damper.
THERMOSTAT
(FIELD SUPPLIED)
TO AC UNIT
COIL (24 VAC)
TO AC UNIT
COIL (GND)
+
−
+
−
GND
24 VAC
LOW HI
Y R C
A/ENT
SENSOR
MOUNTED IN
RETURN AIRSTREAM
A/DIFF-ENT ENTHALPY CONTROL
MOUNTED IN OUTDOOR AIRSTREAM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
CONTROL CONTACTS
BLACK GREEN
WALL CONTROL
RED YELLOW
A FIELD WIRED B
TERMNIALS
OCCUPIED
TIMER/
SENSOR
LOW
COMMON
HIGH
DIRTY
FILTER
INDICATOR
(1.5A–24 VAC)
(RECIRC UNITS )
UNOCC.
RECIRC
CONTACTS
(ERV UNITS)
ENTHALPY
(ERV UNITS)
WHEEL
ALARM
OPTION
(24 VAC)
(−) 24 VAC
(40 VA)
(+) 24 VAC
CLASS 2 VOLTAGE
NOTE:
Connections are all dry contacts
except wall control, wheel alarm
contacts and 24 VAC power
contacts.
Use of 24 VAC circuit requires
isolating contacts
(ex. thermostat) to prevent
interconnection of Class 2
outputs.
Setpoint PN 500053119S (A/Diff-ENT)
Differential PN 500053120S (A/Ent)
Figure G3: Setpoint/differential enthalpy control
THERMOSTAT
(FIELD SUPPLIED)
Y R C
B R W
NO CM NC
TO AC UNIT
COIL (24 VAC)
TO AC UNIT
COIL (GND)
JUMPER
T675A TEMP.
CONTROLLER
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
CONTROL CONTACTS
BLACK GREEN
WALL CONTROL
RED YELLOW
A FIELD WIRED B
TERMNIALS
OCCUPIED
TIMER/
SENSOR
LOW
COMMON
HIGH
DIRTY
FILTER
INDICATOR
(1.5A–24 VAC)
(RECIRC UNITS )
UNOCC.
RECIRC
CONTACTS
(ERV UNITS)
ENTHALPY
(ERV UNITS)
WHEEL
ALARM
OPTION
(24 VAC)
(−) 24 VAC
(40 VA)
(+) 24 VAC
CLASS 2 VOLTAGE
NOTE:
Connections are all dry
contacts except wall control,
wheel alarm contacts and
24 VAC power contacts.
Use of 24 VAC circuit requires
isolating contacts
(ex. thermostat) to prevent
interconnection of
Class 2 outputs.
Setpoint PN 1604130 (T675A)
Figure G4: Thermostat (dry bulb) control
REMOTE FAN SWITCH
LOW HIGH
CONTROL CONTACTS
CLASS 2 VOLTAGE
WALL CONTROL
BLACK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
NOTE:
Connections are all dry contacts
except wall control, wheel alarm
contacts and 24 VAC power contacts.
Use of 24 VAC circuit requires
isolating contacts (ex. thermostat)
to prevent interconnection of
Class 2 outputs.
RED
OCCUPIED
TIMER/
SENSOR
FIELD WIRED
TERMINALS
AB
UNOCC.
RECIRC
CONTACTS
LOW
COMMON
HIGH
DIRTY
FILTER
INDICATOR
(1.5A–24 VAC)
(ERV UNITS)
WHEEL
ALARM
OPTION
(24 VAC)
(ERV UNITS)
ENTHALPY
(−) 24 VAC
(40 VA)
(+) 24 VAC
GREEN
YELLOW
(RECIRC UNITS)
Note: Not all units have two speeds.
Single speed units will be activated
with either Low-Com or High-Com
connection.
JUMPER
Figure G5: Remote fan control
T675A SETPOINT CONTROL
Field installed
low temperature unit control
R
B
W
NOTE:
1. R–W breaks on temperature fall
2. Sensing bulb is placed in supply
airstream after the energy exchanger
CONTROL CONTACTS
CLASS 2 VOLTAGE
WALL CONTROL
BLACK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
NOTE:
Connections are all dry contacts
except wall control, wheel alarm
contacts and 24 VAC power contacts.
Use of 24 VAC circuit requires
isolating contacts (ex. thermostat)
to prevent interconnection of
Class 2 outputs.
RED
OCCUPIED
TIMER/
SENSOR
FIELD WIRED
TERMINALS
AB
UNOCC.
RECIRC
CONTACTS
LOW
COMMON
HIGH
DIRTY
FILTER
INDICATOR
(1.5A–24 VAC)
(ERV UNITS)
WHEEL
ALARM
OPTION
(24 VAC)
(ERV UNITS)
ENTHALPY
(−) 24 VAC
(40 VA)
(+) 24 VAC
GREEN
YELLOW
(RECIRC UNITS)
Figure G6: Low temperature control
IMPORTANT
An Xtra wall control cannot be used with a low tempera-
ture control.
The remote bulb sensor must be placed downstream of
the supply air fan discharge.
CAUTION
Do not use a wall control and remote fan switch at the
same time. Damage to the unit may occur.