11
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English
L-2091 Operation
Setting the Thermostat
After the constant pressure valve is set, the condensing unit
thermostat needs to be set. The set point temperature should
be adjusted as stated in the section “Constant Pressure Valve
(CPV) and Linesets”.
Sight Glass
See “Sight Glass/Moisture Indicator” in the “Installing the
Refrigeration Unit” section.
Metering Device Replacement
CPV Replacement
The constant pressure valve (CPV) is a very simple and
durable metering device. Often small blockages can be cleared
by turning the adjustment knob in and out a few times. In
the unlikely event that the CPV is blocked or the diaphragm
ruptured, it can be replaced as follows:
1. Recover R-134a refrigerant per EPA regulations.
2. Remove CPV from evaporator at quick disconnect fi tting.
3. Remove
the liquid line (1/4" bare copper tube) from CPV
body b
y removing the fl are nut. The fl are n
ut has thread
loc
king compound on it and may require some extra f
orce
to loosen.
4. Connect 1/4" line to new CPV. We
recommend using
threadloc
k on the 1/4" fl are threads.
5. Connect CPV to evaporator. Be careful not to ov
er-tighten
quic
k connect fi ttings. Check that the body of the fi tting
is
tight to the tube adapter
. On the one-piece quick connects
,
tighten to 10-12 ft lbs
.
6. Ev
acuate system and recharge with the correct amount of
R-134a refr
igerant.
7. Set suction pressure and insulate CPV as descr
ibed in
section “Recharging the System”.
TXV Replacement
If the TXV needs to be replaced, review section “Thermostatic
Expansion Valve (TXV) Placement”, and follow this procedure:
1. Recover R-134a refrigerant per EPA regulations.
2. Remove TXV by sweating off the lines.
3. Solder new TXV in place per manufacturer’s instructions.
4. Ev
acuate system and recharge with the correct amount of
R-134a refr
igerant.
5. Set suction pressure and insulate TXV as described in
section “Recharging the System”.
User Maintenance
Seawater System
Check the seawater strainer daily. Remove any debris. If you
are in waters where jellyfi sh or other debris are a problem, you
may fi nd it necessary to add a strainer on the outside of the
through-hull fi tting.
Verify that all seawater connections are tight, and check for
water fl ow from the overboard discharge. The centrifugal
seawater pump does not need any regular maintenance.
Defrosting
Defrosting of your freezer box is required to keep the unit work-
ing at peak performance. Defrost the unit whenever more than
1/4" of ice or frost has accumulated on the plates or box sides.
To defrost, remove all refrigerated items, and then disconnect
the power to the freezer unit. Leave unit off until all ice has
melted.
Be sure to replace drain plug once unit has fi nished defrosting,
if applicable.
Winterizing the System
Make sure all water has drained from the refrigerated box. On
seawater cooled units, close the seacock, and remove inlet
hose from pump and outlet hose from unit to allow all water to
drain from the system. Drain and clean seawater strainer.
Troubleshooting Guide
Before you call for service, review this list. It may save you time
and expense. This list contains common occurrences that are
not a result of defective workmanship or materials. If you need
service after trying these procedures, call your dealer. Note
that wiring diagrams for all units are in Figures 7-12.
Fault: Compressor and fan (or pump) does not run
Possible Reason/Correction:
1. Circuit breaker off.
Turn on or reset circuit breaker
2. Thermostat set incorrectly.
Check thermostat. Set for a cooler setting.
Fault: Fan or pump operates but compressor does
not (high pressure switch or thermal overload has
tripped)
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