September 2020
13
Quest IQ Compressor Wall OMM
o
Control sub-panel with
Main Control
Board
(not shown) and
Operator Panel
(not shown) is normally mounted with the
Main Electric Panel (2)
on the compressor
stand frame.
•
Main Electric Panel
(2) contains main
Disconnect
(77), if one is installed, and
other electrical and control components
(contactors, fuses, control transformer
etc.).
•
Packaged
Dry Cooler
(19), if HVAC system
is equipped with it, is normally mounted
at the end of the HVAC system, adjacent
to compressor compartment/supply air
end (see Pic. D.1D).
Control System
The HVAC system control system is composed of sensors, spread throughout the HVAC system,
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.);
b)
Combo
sensor is used to monitor air temperature and
humidity.
Compressor operation is monitored with
pressure sensors
(Pic. D.3):
c)
Pressure Transducers
(only a single set of transducers on the lead
circuit only for information purpose, not used for control) and
d)
Pressure Switches
(fast-reacting backup safety).
Note.
Sensors and safeties approximate location is shown on Pic. D.1B and
D.1C
–
refer as
needed.
•
RA Combo
Sensor
(
21
) measures temperature and humidity of the pool room air (Return Air) entering the
HVAC system. It is located at the return air ductwork connection to the HVAC system.
•
SA temperature sensor
(
24
) measures the temperature of the air leaving the HVAC system (supplied to the
premise). It must be located
downstream of the space heater
:
o
SA temperature sensor of HVAC system, equipped with gas heater, would be composed of four
regular temperature sensors, installed in different points at supply duct connection, averaging
temperature reading.
19
Pic. D.1D
b
a
c
d
Pic.D.3
Pic. D.2
