Sea Frost BG 2000 - Manual (Page 28)

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b) If pressure reading is over 100 psig with compressor off, proceed to check charge
level via sight glass and charge if needed.
CHARGE LOSS INDICATES A LEAK THAT MUST BE CORRECTED.
STEP 2. If a system continues to operate inefficiently after Step 1, check for moisture
or dirt plugging the valve. Run the system, observing closely the gauge readings and
plates temperature, noting the following.
a) If system is warm upon start-up, a DIRT-PLUGGED Valve will show an
immediate deep vacuum reading on low side. Consult Sea Frost for cleaning
techniques.
b) MOISTURE-PLUGGED VALVE on a properly charged system is indicated by
deep vacuum readings on low side after a few minutes of operation from warm,
FOLLOWED BY any combination of these symptoms:
-High side compressor discharge fitting temperature drops from hot to warm.
-Suction line from valve remains warm.
-Compressor current draw (Running amperes.) drops.
-Moisture enters either through a low side leak or during initial installation and will freeze
at the valve unit, reducing or eliminating refrigeration. Turning off system and allowing
the valve to warm to above freezing, then restarting, may temporarily solve the problem.
If not, change RFD as follows.
STEP 3. To change a saturated RFD, allow the system to warm to ambient
temperature, thereby preventing moisture from condensing in the circuit upon opening.
A light bulb in the refrigerator box will speed the warming of the plates. Recover the
refrigerant from system through the suction service port SLOWLY to prevent liquid and
oil from escaping. " WARNING: BEFORE DISASSEMBLY OF ANY PART IN THIS
SYSTEM, BE SURE CHARGE IS COMPLETELY RECOVERED. With a backup
wrench holding the brass body of the Swagelok fittings loosen and back off the nuts.
The tubing may be pulled out of the fittings. Remove the RFD. Replace only with an
identical unit by size and color: THE SEA FROST RFD is a drier and also a
receiver/filter. The desiccant and the oil in the Sea Frost RFD are special to this
system and R-404a. Using the wrong oil will destroy the system.
NOTE: This system contains a measured amount of lubricating oil. Be sure the RFD
being installed is a blue SEAFROST BG 2000 R-404-a RFD. Record all component
exchanges in this on-board owner's manual.