EMI CAC_36, Инструкция по установке, эксплуатации и обслуживанию

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41 Cassette Air Handler
WALL THERmOSTAT CONTROL – mOdELS CAHA ANd CACA
Continued
INfRAREd CONTROLLER WITH OpTIONAL
WALL THERmOSTAT CONNECTION – mOdELS CAHB ANd CACB ONLy
TROUBLESHOOTINg pROCEdURE
Continued
To check for an electric heat signal, place
a voltmeter across terminals “W” and “C”
of the indoor unit. When working correctly,
there should be a reading of 24 Vac.
To stop heating operation, place the set
-
point temperature below the room tempera
-
ture. The outdoor unit and electric heat will
stop while the indoor fan will remain on for
an additional sixty (60) seconds.
for optional
wall thermostat operation, 24
Vac can also be measured across low V
olt
terminals “G” and “C” of the Cassette.
NOTE:
Cassette operation can be controlled
through either a wall mounted thermostat or
an optional Infrared Hand Held Controller. For
selection of which control method refer to the
Cassette Control DIP Switch Selections located
under CACB/CAHB Sequence of Operation.
COOLINg ONLY UNITS, INFRARED HAND
HELD CONTROLLER, MODEL CACB
Cooling only units require an 18 AWG low
V
olt interconnecting wires between the in-
door and outdoor units. If the Cassette con
-
troller is configured for wall thermostat op
-
eration then a connection is also required
between the air handler and wall thermo
-
stat. Refer to low volt interconnect diagram
Figure #13 for low
V
olt interconnect wiring
connection.
NOTE:
“W” is required for units with electric heat only
“C” may not be needed on some thermostats
The Infrared Hand Held Controller or wall
mounted thermostat will switch on and off
the outdoor unit through the yellow “Y” low
volt terminal. When the thermostat is call-
ing for cooling, 24 Vac can be measured
across terminals “Y” and “C” of the indoor
or outdoor units.
for optional
wall thermostat operation, 24
Vac can also be measured across low volt
terminals “Y I” and “C” of the Cassette.
The indoor unit contains an electronic anti-
short cycle timer feature (ASCT) that will
prevent the outdoor unit from short cycling.
After the room temperature is satisfied
there will be a three (3) minute delay before
the outdoor unit s allowed to re-start.
The optional
Infrared Hand Held Controller
or wall mounted thermostat will also control
the indoor fan by switching high Volt power
to the fan motor with the fan relay. When
energized, high Volt power can be mea
-
sured between the relay output and the L2
terminal of the incoming power supply.
for optional
wall thermostat operation, 24
Vac can also be measured across low volt
terminals “G” and “C” of the Cassette.
HEAT pUMp UNITS, INFRARED HAND
HELD CONTROLLER, MODELS CAHB
Heat pump units require an 18 AWG low
V
olt interconnecting wire between the in-
door unit and outdoor units. If the Cassette
controller is configured for wall thermostat
operation then a connection is also required
between the air handler and wall thermo
-
stat. Refer to low
Volt interconnect diagram
Figure #13 for low
V
olt interconnect wiring
connection.
NOTE:
“O” is required for heat pump operation. The re-
versing valve is energized in cooling.
“W” is required for units with electric heat only.
“C” may not be needed on some thermostats.