5-2
Condenser Fan and Evaporator Fan Rotation
Electrical Maintenance
CSR-20 & CSR-40, September 1999
2.
If the high pressure cutout switch fails to reset, clear the
HPCO alarm (code 10). Press the ALARM key on the
controller. Then Press the DOWN key until ENTER
flashes in the left display. Then press the ENTER key.
The Alarm LED should turn OFF and the compressor re-
start.
WARNING: When alarm codes are cleared by
pressing the ENTER key, the unit will start auto-
matically.
3.
If the unit returns to the Pause Alarm mode (alarm code
10), continuity check the high pressure cutout switch cir-
cuit wiring with a high quality multimeter.
4.
If the high pressure cutout circuit is OK, replace the high
pressure cutout switch.
Condenser Fan and Evaporator Fan Rotation
Condenser Fan
Check for proper condenser fan rotation by placing a small
cloth or sheet of paper against the condenser fan grille on the
front of the unit. Proper rotation will blow the cloth or paper
away from the grille. Improper rotation will hold the cloth or
paper against the grille.
NOTE: If unit operating conditions do not require
condenser fan operation, check the condenser fan
rotation by performing an AMPS/CFH (high speed
condenser fan) test from the Test Menu of the
µµ
P-D
controller.
If the condenser fan is rotating backwards, refer to the unit
wiring diagram to correct fan motor wiring at the fan motor
junction box or condenser fan contactor. To correct improper
fan rotation, reverse any two fan power cord leads at the con-
denser fan contactor (disconnect power supply before revers-
ing leads). DO NOT move the CH ground wire.
Evaporator Fans
Visually inspect the evaporator fan blades for proper rotation.
Arrows located on the underside of the fan deck indicate the
correct direction of rotation.
NOTE: Check both High and Low Speed evaporator
fan rotation by performing an AMPS/EFH (high speed
evaporator fan) test and AMPS/EFL (low speed evap-
orator fan) test from the Test Menu of the
µµ
P-D con-
troller.
If an evaporator fans rotate backwards on one or both
speeds, refer to the unit wiring diagram to correct motor wiring
at the fan motor junction box or evaporator fan contactor (dis-
connect power supply before reversing leads). (DO NOT move
the ground wire which is labeled CH.)
NOTE: Evaporator fan motor wires EF1, EF2 and EF3
are used on LOW SPEED fan operation. Wires EF11,
EF12 and EF13 are used on HIGH SPEED fan opera-
tion.
NOTE: To diagnose the controller phase selection
system if both the condenser fan and evaporator
fans are rotating backwards, see the Diagnosis
Manual for Thermoguard
µµ
P-D Microprocessor
Controller, TK 41230.
Electric Heaters
Six electric heater elements are located underneath the evapo-
rator coil. If a heater element is suspected of malfunctioning,
inspect the connections:
• If the connections appear correct and secure, isolate and
check the resistance of each individual heater element by
disconnecting it from the circuit.
• Check resistance with an ohmmeter.
NOTE: When repairing heater connections, protect
the new connections from the ingress of moisture
with heat shrink tubing. All heaters should be
secured to prevent contact with sharp metal edges.
