2
FAN COIL DESCRIPTION
AND TROUBLESHOOTING
FY5, FH4, PF4 (even sizes)
and FF1E (even
sizes),
FAN MOTOR
The motor is two or three speed direct drive. High--speed lead is
black, low--speed lead is red, and common lead is yellow. Be sure
proper blower speed has been selected..
The motor is turned on through two different routes. The first
occurs when thermostat calls for the fan in cooling, heat pump, or
fan--only mode. A 24--Vac signal is sent to relay, causing relay to
close its normally open contacts, turning fan on.
The second occurs when there is a call for electric heat. A 24--Vac
signal is sent to heater sequencer/relay, causing it to close, directing
230V through the normally closed contact of fan relay, turning fan
on. The fan remains on until sequencer/relay opens.
If motor does run, test motor for an open winding or a winding
shorted to motor case. If either is present, replace motor.
ELECTRIC HEATER SERVICE
Service can be completed with heater in place. Shut off power
before servicing.
A. Limit Switch
Refer to Electric Heater Function and Troubleshooting section of
this manual.
B. Sequencer
Refer to Electric Heater Function and Troubleshooting section of
this manual.
C. Transformer
A 40--VA transformer supplies 24--V power for control circuit.
Check for 208/230V on primary side of transformer. If present,
check for 24V on secondary side.
NOTE: Transformer is fused. Do not short circuit.
D. Fan Relay
Relay coil is 24--V. Check for proper control voltage. Replace relay
if faulty.
CLEANING OR REPLACING REFRIGERANT
FLOW--CONTROL DEVICE
Refer to Fig. 22 and instructions given in “Piston Body Cleaning
or Replacement” section.
The refrigerant flow--control device is protected by a wire mesh
strainer. It is located inside the 3/8--in. liquid tube at field braze
joint next to flow--control device. Access to strainer is through field
braze joint.
SEQUENCE OF OPERATION
A. Condensing Unit
COOLING
When thermostat calls for cooling, the circuit between R and G is
complete and single--pole single--throw relay FR is energized. The
normally open contacts close causing blower to operate.
The circuit between R and Y is also complete. This completed
circuit causes contactor in outdoor unit to close which starts
compressor and outdoor fan.
HEATING
When thermostat calls for heating and FAN switch is set on AUTO,
the circuit between R and W is complete. The heater sequence SEQ
is energized which closes contacts of relay. There will be a time
delay. This completed circuit energizes all heating elements HTR
and blower motor.
B. Heat Pump
COOLING
On a call for cooling, the thermostat makes circuits R--O, R--Y, and
R--G. Circuit R--O energizes reversing valve, switching it to
cooling position. Circuit R--Y energizes contactor starting outdoor
fan motor and compressor. Circuit R--G energizes indoor unit
blower relay starting indoor blower motor.
When thermostat is satisfied, its contacts open de--energizing
contactor reversing valve and blower relay. This stops compressor
and fan motors.
HEATING
On a call for heating, the thermostat makes circuits R--Y and R--G.
Circuit R--Y energizes contactor starting outdoor fan motor and
compressor. Circuit R--G energizes indoor blower relay starting
blower motor.
Should temperature continue to fall, R--W circuit is made through
second--stage room thermostat bulb. Circuit R--W energizes a
sequencer bringing on supplemental electric heat.
When thermostat is satisfied, its contacts open de--energizing
contactor and sequencer. All heaters and motors should stop.
CES013003--00, 01 (HK61EA002, HK61EA006)
CONTROL BOARDS
This section of the service manual describes the CESO130003--00
and --01 PCB by examining the functional operation of the PCB
components.
Printed Circuit Board (PCB) Component
Layout of the actual PCB is depicted in Fig. 1 and Fig. 2.
1. The low--voltage stripped leads are used to connect the
24--V side of transformer to indoor thermostat and outdoor
section.
2. A 5--amp fuse is used to protect the low--voltage trans-
former secondary.
3. The fan relay is controlled by thermostat and turns fan on
and off.
4. A plug is used as the connection for PCB power and electric
heaters. Note the pin numbers on plug.
5. A time--delay relay circuit keeps fan motor running for ap-
proximately 90 seconds after G is de--energized. The time--
delay can be defeated by cutting jumper JW1 on the
CES0130003--01, HK61EA002 and HK61EA006.
UNIT FUNCTIONS
A. Transformer
1. Proper Wiring of Transformer Primary or High Side
Yellow wire from Molex plug is wired to C terminal on
transformer and black wire from PCB relay (normally--
open) terminal is wired to 208--V or 230--V terminal on
transformer. Units are factory wired at 230--V terminal.
2. Proper Wiring of Transformer Secondary or 24--V Side
Red wire of transformer is wired to T terminal on PCB and
brown wire of transformer is wired to C terminal on PCB.
NOTE: T terminal on PCB is used to protect the transformer. T
terminal is connected through the fuse to R terminal on PCB.
B. Indoor Fan
1. Wiring
Indoor fan motor yellow lead is wired to C terminal on
transformer. The red, blue, or black speed lead is wired to
SPT terminal on fan relay part of PCB. Units are factory
wired on medium speed (blue lead connected).
NOTE: Unused fan speed leads must be capped or taped off to
prevent direct short to cabinet surface.
2. Functional Control
a. Thermostat and Relay Control
When thermostat calls for the fan in cooling, heat pump,
heating, or fan--only mode,a24--Vacsignal issent to relay.
This causes the relay to close its normally--open contacts,
turning on fan.When thermostat no longercallsforthefan,
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