FBD FBD553D Installation, Operation And Service Manual - page 29
(Section 14.21 continued from previous page.)
G. Lower Board problem.
G. Test lower board for +5, +15, and
–15 outputs on test points (see
Figure 14.3).
H. 353 VA Transformer problem.
H. Test transformer for 220VAC input
and 24VAC and 12VAC output
(see Figure 14.3).
I.
Compressor failure, or
I.
Wait for compressor to cool.
overheated.
Check amperage draw (normal
running 18 amps) on compressor.
Check compressor wiring and
terminals. Replace compressor,
if necessary.
14.22 Compressor runs long
A. Return temperature not
A. Verify that Return Temperature
time but won’t freeze
dropping.
drops below 20°F. Return
down.
Temperature should achieve 20°F
within 7 to 25 minutes of startup
(no drinks dispensed).
B. Airflow through condenser
B. Clear condenser of blockage.
is blocked. Dirty filter.
Clean air filter.
C. Hot gas valve is activated
C. Select "Defrost Sol" in
in Manual On/Off
“Manual ON/OFF”; test solenoid,
then turn off.
D. Base refrigeration settings.
D. Load all Defaults to ensure factory
settings.
E. Hot gas valve is stuck open,
E. Recover refrigerant and remove
or debris is preventing valve
blockage or replace valve, if
from closing.
necessary. Recharge system with
65.0 oz. of R404-A.
F.
Expansion valve not opening.
F.
1.
Test expansion valve coil to
ensure it is receiving 24VAC.
Replace expansion valve if
plunger inside doesn't move.
Recover refrigerant and replace
valve. Recharge system with
65.0 oz. of R404-A.
2.
Test relay board for 24VAC
output and 5VDC relay coil
input. Replace, if necessary.
G. Expansion valve restriction.
G. Recover refrigerant and remove
blockage or replace valve if
necessary. Recharge system with
65.0 oz. of R404-A.
H. Refrigeration leak or low
H. Put gages on system and check
refrigerant charge.
pressures. Single side suction
should be 32-35 psi, dual side
42-45 psi. Single and dual side
discharge should be 275-300 psi.
Check for and repair leaks,
recharge system with 65.0 oz. of
R404-A.
CAUTION
DO NOT PRESSURIZE LOW SIDE (EVAPORATOR AND COMPRESSOR SUCTION) ABOVE 150 PSI
FOR ANY REASON! COMPONENTS WILL FAIL AND WARRANTIES WILL BE VOID.
14.23 High head/suction
A. Condensor air flow restricted.
A. Check for air flow restriction, clean
pressure. Contact
condensor and air filter.
FBD Warranty Dept.
B. Compressor damage
B. Check amp draw on compressor
before tapping system
(normal running 18 amps).
if unit is under
C. High ambient temperature.
C. Temperature surrounding unit
warranty!
should be less than 90°F.
TROUBLE
CAUSE
REMEDY
26