Specifications

VCES-ERV-IOM-3B – Indoor ERV
24
Wall Control Connection
Two types of remote wall controls are available:
1. Standard wall control with fan switch and dehumidi-
stat control.
2. Xtra wall control with fan mode selection, dehumidi-
stat control and maintenance indicator.
The remote wall controls work with the integrated elec-
tronic controls within the unit to control ventilation se-
quences. Each wall control above has different features
and will require four-wire connection to the unit as shown
below. Without the wall control, fans can be operated
with dry contacts or a switch as in Figure E5.
Occupied Timer/Sensor Connection
Occupancy control is achieved by connection to the termi-
nal interface shown below. These terminals require a dry
contact which could be provided by a number of types of
controls such as a timer, light sensor, occupancy sensor,
Building Management System or other. The unit will not
operate unless these contacts are closed!!
The drawing below shows a factory installed jumper and
programmable timer option.
Enthalpy Control
Energy Recovery Ventilators (ERVs) can be controlled by
an enthalpy controller that switches between free cooling
and AC unit cooling. When free cooling is possible, the
ERV will ventilate without energy recovery (the enthalpy
wheel stops) on a call for cooling. The ventilation rate is
not affected. If the unit is not operating, enthalpy control
contact will initiate low speed ventilation. The enthalpy
control must be connected in conjunction with a cooling
thermostat control to prevent free cooling from initiating
in heating seasons as shown below.
Appendix E: Terminal Control Diagrams
Wall
Control
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)
JUMPER
Figure E1: Wall control connection
JUMPER
(factory installed)
OCCUPANCY CONTROL
(field installed)
NSB Timer
1
M
2345
JUMPER
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)
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 E2: Occupied timer/sensor connection
IMPORTANT
All controls accessories (ex. night setback timer, CO
2
controller, enthalpy controller, smoke detector or wheel
rotation sensor) intended to provide a contact closure for
occupancy control across terminals 3 and 4 cannot be
used in conjunction with the Xtra wall control.
If a wall control is required in addition to any of these
options, only the standard wall control may be used.
Without these options, a factory installed jumper across
terminals 3 and 4 must be installed.
IMPORTANT
All controls accessories (ex. night setback timer, CO
2
controller, enthalpy controller, smoke detector or wheel
rotation sensor) intended to provide a contact closure for
occupancy control across terminals 3 and 4 cannot be
used in conjunction with the Xtra wall control.
If a wall control is required in addition to any of these
options, only the standard wall control may be used.
Without these options, a factory installed jumper across
terminals 3 and 4 must be installed.