19
PN 20009722 REV F, [08/01/2020]
THERMOSTAT OPERATION
CAW Wall Mounted Thermostat Operation
Thermostat Selection
• Choose 24 Vac, dry contact type thermostat that
matches your application.
• EMI equipment is compatible with most standard
bimetal, mercury bulb, digital electronic or power-
stealing thermostats.
• Refer to Electrical Wiring for thermostat, chilled water
valve and optional hot water valve wiring connections
to CAW unit along with thermostat manufacturer's
instructions for wiring and special operation or
programming. See page 17.
1. Cooling Only Thermostat Selection
Select a thermostat compatible with chilled water cooling
system and chilled water valve selected. Thermostat should
have “R”, “Y” and “G” terminals. Thermostat may also have
“C” terminal.
2. Cooling with Electric or Hot Water Heat
Thermostat Selection
Select thermostat compatible with chilled water cooling and
hot water or electric heating system with water valve(s)
selected. Thermostat should have “R”, “Y”, “W” and “G”
terminals. Thermostat may also have “C” terminal.
Sequence of Operation Wall Mounted
Thermostat
Follow all installation and electrical wiring instructions
prior to applying power to the unit. If CAW unit is
equipped option heating, either electric or hot water, verify
thermostat is set to energize the fan with call for heating.
1. Fan Operation
Some thermostats are equipped with AUTO/ON fan switch.
Placing switch ON will run the fan continuous. Placing
switch in AUTO position will cycle the fan with call for
heating or cooling through the “R” and “G” low volt terminal
connections.
After thermostat is satisfied and call for heat or cooling is
removed or the fan switch is set to auto the indoor fan will
remain on for sixty (60) seconds to purge remaining energy
from unit thereby increasing efficiency.
2. Cooling Operation
A. Apply power to unit and place system switch in
“COOL” mode. Adjust set-point temperature below
room temperature. Chilled water valve will open
and fan motor(s) will energize.
B. Place set-point temperature above room
temperature. Chilled water valve will close and fan
remains on for additional sixty seconds.
2. Cooling with Electric Heat or Hot Water Heat
Operation
A.
Set thermostat Configuration for cooling/electric
heat operation. Follow thermostat manufacturer's
instructions for configuration settings.
B. Apply power to the unit and place system switch in
“HEAT” mode. Adjust set-point temperature above
room temperature. Electric heat will energize or
hot water valve will open and fan motor(s) will
energize.
C. Place set-point temperature below room
temperature. Electric heat will switch off or hot
water valve will close and fan remains on for
additional sixty seconds.
