Carrier 50SZ Series Installation, Start-Up And Service Instructions Manual page 20

Table 9—Cooling and Heating Troubleshooting Chart (Cont'd)
SYMPTOM
Suction pressure too low
Compressor runs but outdoor fan does not
IFM* does not run
IFM* runs when it should be off
IFM* operation is intermittent
* IFM–Indoor Fan Motor
I. PRELIMINARY INFORMATION
Model No .............................................................................................................................................................
Serial No ..............................................................................................................................................................
Date .....................................................................................................................................................................
Technician ...........................................................................................................................................................
Job Location ...........................................................................................................................................................
II. PRE-START-UP
____ Verify that all packing materials have been removed from unit
____ Remove all shipping holddown bolts and brackets per installation instructions
____ Verify that condensate connection is installed per installation instructions
____ Check all electrical connections and terminals for tightness
____ Check that indoor (evaporator) air filter is clean and in place
____ Verify that unit installation is level
____ Check fan wheel propeller for location in housing and setscrew tightness
III. START-UP
Supply Voltage: L1-L2 __________
Compressor Amps: L1 __________
Indoor Fan Amps: __________
TEMPERATURE
Outdoor-Air Temperature: __________ DB
Return-Air Temperature: __________ DB __________ WB
Heat Pump Supply Air: __________
Electric Heater Supply Air: __________
PRESSURES
Refrigerant Suction __________ psig
Refrigerant Discharge __________ psig
____ Verify Refrigerant charge using charging tables
Copyright 2005 CARRIER Corp. • 7310 W. Morris St. • Indianapolis, IN 46231
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 101
Tab 6 8
(Cool) Dirty air filter
(Heat) Outdoor coil frosted
Low refrigerant charge
Metering device or low side restricted
(Cool) Insufficient coil airflow
(Cool) Temperature too low in conditioned area
(Cool) Outdoor ambient below 40° F
Field-installed filter-drier restricted
NC (normally closed) contacts on defrost board
open
Blower wheel not secured to shaft
Insufficient voltage at motor
Power connectors not properly sealed
Motor programmed with a delay profile
With thermostat in off state, the voltage on G,
Y1,Y, Y2, W with respect to common, should be
1/2 of actual low voltage supply
Water dripping into motor
Connectors not firmly sealed
Start-up checklist
(REMOVE AND STORE IN JOB FILE)
Printed in U.S.A. Catalog No. 50SZ-1SI
CAUSE
Replace filter
Move timer on control board to 30 minute
between defrost cycles
Check for leaks, repair and recharge
Remove source of restriction
Increase air quantity
Check filter–replace if necessary
Reset thermostat
Install low-ambient kit
Replace
Check condition of relay on board
Replace if necessary
Properly tighten blower wheel to shaft
Determine cause and correct
Connectors should snap easily; do not force
Allow a few minute for motor to shut off
If measured voltage is more than 1/2, the
thermostat is incompatible with motor
If voltage is less than 1/2, the motor has failed
Verify proper drip loops in connector wires
Gently pull wires individually to be sure they are
crimped into the housing
REMEDY
Pg 20 8-05 Replaces: New