W7340 And W7345 - Honeywell Design and Application Technical Reference Manual

One enthalpy or dry bulb and
one mixed/supply air sensor
required. Second enthalpy
sensor optional.
The W7340 was a full enthalpy economizer
used in an OEM unit to provide a totally
integrated control system. The W7345
provided temperature (OAT) control only; it did
not have an option for a return air sensor, DCV
sensor or exhaust control.
The W7340A and B modules did not have the
ability to set the outdoor air damper to a
maximum position for DCV, they incorporated
a minimum position setting that defaulted to
20% but could be overridden using the on-
board pot or Modbus communication link to a
maximum of 50% open.

W7340 and W7345

Optional room CO
2
sensor on W7340
models
If the CO2 sensor failed, the OA damper
position would go to a position for maximum
occupancy ventilation. If the minimum position
set point was higher than the DCV maximum
position, on sensor failure, the damper would
drive to the higher of the two of DCV maximum
and minimum position settings.
There was no limit on the damper position on
a call from the CO
100% open.
37
Section 3 - Types of Analog Economizers
W7340
W7340 and W7345 mount
on flat surface or on a
M7215 motor
sensor (DCV). It could go
2
Honeywell Economizers 63-8594-02
W7345