Wiring; Optional Applications; Representative Locations Of Connected Economizer System Devices - Honeywell W7212 Product Data

Mount the CO2 sensor according to the manufacturer
specifications. If not available, use the following guidelines:
1. Mount sensor in an area with unobstructed air
circulation.
2. Connect it to the AQ and AQ1 terminals of the W7212
(see Wiring section for details).
DISCHARGE
AIR SENSOR
2
C7046A
INDOOR
FAN
DISCHARGE
AIR
1 FOR DIFFERENTIAL ENTHALPY, THE TWO C7400
ENTHALPY SENSORS ARE CONNECTED TO THE
ECONOMIZER LOGIC MODULE—ONE
IS MOUNTED IN RETURN AIR, AND THE OTHER IS
MOUNTED IN OUTDOOR AIR.
2
USE EITHER MIXED AIR SENSOR OR DISCHARGE
AIR SENSOR, NOT BOTH.
Fig. 4. Representative locations of connected economizer system devices.

Wiring

CAUTION
Electrical Shock or Equipment Damage Hazard.
Can shock individuals or short equipment
circuitry.
Disconnect power supply before installation.
IMPORTANT
1. All wiring must comply with applicable local codes,
ordinances and regulations.
2. Refer to Table 2 for a list of the wiring diagrams and
corresponding Figure numbers in this document.
3. All device inputs and outputs must be 24 Vac Class 2.
4. Ensure proper polarity of sensor connections.
Incorrect polarity negates the sensor signal.
DIRECT
EXPANSION
COIL
W7212,
W7213,
W7214
W7212, W7213, W7214 ECONOMIZER LOGIC MODULES
3. Adjust the DCV potentiometer setpoint to correspond to
DCV voltage output at the threshold.
COMMERCIAL
THERMOSTAT
2
C7150B
MIXED AIR
SENSOR
HONEYWELL
ACTUATOR
1
ENTHALPY
C7400
SENSOR
EXHAUST
FAN
RETURN AIR

Optional Applications

Heat Pump Changeover
(W7213, W7214 only)
In heat pump applications, the controller must have control of
the changeover valve. To provide the logic module with the
information necessary for proper information, there must be a
connection to the logic module O/B terminal. This terminal
alerts the logic module as to when the system operates in
cooling (the only time the economizer is used).
IMPORTANT
During heating applications with defrost, make sure to
break the connection to the economizer using an iso-
lation relay.
W7213 (CHANGEOVER TERMINAL B)
Connect the B terminal according to the following details:
— 24V power to B: System is in heating mode.
— No power to B: System is in cooling mode.
W7214 (CHANGEOVER TERMINAL O)
Connect the O terminal according to the following details:
— 24V power to O: System is in cooling mode.
— No power to O: System is in heating mode.
5
DCV
C7232
SENSOR
ENTHALPY
1 C7400
SENSOR
OUTDOOR
AIR
EXHAUST AIR
M19547C
63-2596—09