Operating instructions

PG. 18 #8401 QC-100 INSTALLATION & MAINTENANCE MANUAL
The condensing units operate only when the
system is in a cooling mode and the food storage
compartment requires a decrease in temperature.
If it appears the condensing units are not
functioning properly and the General Diagnostic
Procedure (4.2.4) on the preceding page was
unable to pinpoint the specific cause, the
following steps should be taken for further
diagnosis.
5.3.1 CONTROL CABLE CONNECTIONS:
Open the key lock on the alphanumeric
keyboard display enclosure. Inspect each
circuit board connection wire to be certain
they are firmly attached to the board. Pay
particular attention to the gray ribbon cable
which originates through a hole behind the
circuit board. This cable should be firmly
attached to the black connector marked
I/O
CONNECTOR
. The additional gray ribbon cable
originating from the display should be firmly
attached to the black connector marked
LCD
DISPLAY
. The black connector marked PRINTER
should only be connected if the original
factory order specified a parallel printer port
instead of the normal serial printer port.
If it is determined the control cable
connections are secure, the problem may be
related to a fuse, relay, or device failure. At
this point in the diagnosis check the fuses.
5.3.2 CONDENSING UNIT FUSES:
Quickchiller condensing units, fans, heaters,
and solenoids are fused with 20mm fuses.
Fuses are located on the relay board which is
mounted within the electrical enclosure.
WARNING
MAKE CERTAIN THE MAIN POWER IS
OFF BEFORE SERVICING.
Disconnect main incoming A.C. power to the
unit. When all power to the system is OFF,
gain access to the electrical enclosure and
remove the enclosure cover. Before removing
the fuses, measure the voltage to make certain
the power has been completely disconnected.
Each of the two compressors have one fuse on
L
1
and L
2
for a total of four fuses. Test each
fuse with an ohm-meter and replace if
necessary only with an identical fuse.
If the fuses do not require replacement or if
the compressors still do not function, call the
factory for assistance.
5.4 FANS, HEATERS, SOLENOIDS
If it appears the fans, heaters, or solenoids are
not functioning properly and the General
Diagnostic Procedure on the preceding page was
unable to pinpoint the specific cause leading to
repair, follow general directions prescribed for
CONTROL CABLE CONNECTIONS and
CONDENSING UNIT FUSES under the
Condensing Unit heading on this page.
5.0 — Diagnostic and Repair Procedure
5.3 CONDENSING UNITS