Carrier 26H - Manual (Page 52)

26H S E R V I C E Carrier
32. TESTING THE SOLENOID VALVE
The solenoid valve passes hot discharge gas to the
evaporator during the harvesting portion of the
cycle. It is energized by the main control thermo­
stat only during the defrost cycle.
If, upon completion of harvesting, the valve fails
to close or closes only partially, the discharge
side of the valve will remain warm and little or no
freezing will occur in the evaporator. If, on the
other hand, the valve fails to open, no harvesting
will occur and the ice cubes will remain frozen in
the evaporator. To determine whether power is
reaching the valve, connect a test light across the
leads to the valve. A lighted lamp indicates power
is supplied to the coil. The opening and closing
of the valve can be heard when standing next to
the machine. This will indicate whether the valve
is operating but will not prove whether the valve is
seated. A hissing noise at the valve indicates a
poorly seated valve. Poor seating of the valve will
result in excessive freezing time. Malfunctioning
of the valve may also be due to low voltage or poor
electrical connections.
The solenoid coil (and the valve stem on Sporlan
Valves) can be replaced without taking the valve
body from the system; however, if necessary, the
entire valve can be removed by slowly bleeding the
refrigerant charge as described in section 8, and
unsweating the connections. Dismantle the replace­
ment valve and cover the body with wet cloths be­
fore brazing to prevent damage to the valve. Silver
solder is used on the connections. State reguired
voltage when ordering a replacement solenoid valve
or coil since the 115 volt and 230 volt coils are
not inerchangeable.
WINTERIZING ICE MAKERS
For proper operation of the controls, any units which
are operated through the winter season should be
located where the temperature will not fall below
50°. Where a unit is shut down during the winter
season, certain precautions are required if the tem­
perature surrounding the unit falls below freezing.
The unit may be damaged if the following precau­
tions ore not taken:
1. The Ice Maker should be cleaned and descaled
before shutting down for the winter.
2. Disconnect inlet water supply line. Drain
water pan by removing siphon standpipe.
3. Turn selector switch and start unit; run until
compressor goes "off" on high pressure cutout.
This will cause the water regulating valve to
open fully, permitting water to drain out by
gravity.
4. Disconnect flare connection on outlet side of
water regulating valve. Some water will drain
out.
5. To prevent any trapped water from freezing
when unit is not used during winter months,
it is necessary to "blow out" the circulating
water lines. This may be done by connecting
a small refrigerant Freon drum to the dis­
connected flare nut. Open refrigerant drum
slightly and admit small amount of gas. The
gas pressure will blow out the trapped water.
6. Disconnect refrigerant drum; reconnect flare
nut to water regulating valve. Leave water
supply line disconnfected. The unit should
be tagged, stating in what condition the ma­
chine is left so that next year a service man
will know exactly what should be done to start
the unit up.
7. The "trapped" water in the main control over­
flow well should be blown out. Blow through
the top of well where the control capillary
enters.
•8. Remove drain plug from siphon interchanger.
9. Make sure disconnect switch is in "off" posi­
tion. Remove the fuses, or otherwise dis­
connect the power supply.
10. After a long period of shut down or upon origi­
nal installation. Ice Cube Makers should be
observed through two complete cycles before
the mechanic leaves the job.
i
26H-57PD 52