Control System - Seresco CWT Series Operation And Maintenance Manual

Control sub-panel with Main Control
o
Board (17) and Operator Panel (18) is
normally mounted on the compressor
stand frame.

Main Electric Panel (2) contains main
blower(s) VFD (variable frequency drive)
(78), main Disconnect (77), if one is
installed, and other electrical and control
components (contactors, fuses, control
transformer etc.).

Packaged Outdoor Fluid Cooler (20), if
dehumidifier is equipped with it, is
normally mounted at the end of the
dehumidifier, adjacent to compressor
compartment/supply air end (see Pic.
D.1D).

Control System

The dehumidifier control system is composed of sensors, spread throughout the dehumidifier, Main Control
Board, Operator Panel and other electric components, located in the Main Electric Panel.
Temperature Sensors (Pic. D.2):
a) Temperature sensors (thermistors) are used to monitor
various temperatures (air, water, compressor, etc.);
Combo sensor is used to monitor air temperature and
b)
humidity.
d
c
Pic.D.3

RA Combo Sensor (21) measures temperature and humidity of the pool room air (Return Air) entering the
dehumidifier. It is located at the return air ductwork connection to the dehumidifier.

OA Temperature Sensor (22) measures outdoor air temperature; it's located at the OA filter rack.
As an option, the combo sensor (instead of regular thermistor) can be installed at the OA intake to
o
measure both the temperature and humidity of the outdoor air.

ET (EvapT) Temperature Sensor (23) measures the temperature of air leaving evaporator coil. It's located
directly downstream of the evaporator coil(s) (one sensor per each compressor circuit).

SA temperature sensor (24) measures the temperature of the air leaving the dehumidifier (supplied to the
premise). It must be located downstream of the space heater:
January 2022
19
Compressor operation is monitored with pressure sensors (Pic. D.3):
Pressure Transducers (only a single set of transducers on the lead
c)
circuit only for information purpose, not used for control) and
Pressure Switches (fast-reacting backup safety).
d)
Note. Sensors and safeties approximate location is shown on Pic. D.1B and
D.1C – refer as needed.
17
a
Seresco CWT Series OMM
Pic. D.1D
b
Pic. D.2