Gaymar MEDI-THERM II MTA5900 Series, Руководство по обслуживанию

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SERVICE MANUAL
Medi-Therm II REPAIR PROCEDURES
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• The smaller molecular size of R-134a refrigerant allows it to leak from
smaller openings than R-12.
• Prior to charging the system, Gaymar recommends evacuating the system
to below 500 microns. Then, perform a vacuum decay test to assure there
is not a large differential between the system and the vacuum pump. After
5 minutes, the system should still be at 500 microns or below.
• For optimum performance, charge the R-134a system with 8.75
ounces of R-134a refrigerant.
Make sure that the entire 8.75 ounce
charge is pulled from the gauge manifold and hoses into the system before
disconnecting.
• If it is necessary to check a unit’s charge, purge the refrigerant gauge manifold
and hoses with R-134a refrigerant from an external source before opening
the service valves to prevent affecting the unit’s charge.
In a properly charged unit, the low side refrigerant gauge pressure
should be approximately 15 to 25 psi; the high side pressure should be
approximately 115 to 135 psi, under the following conditions:
1. the unit’s wraparound is removed;
2. the ambient temperature is 72°F (22.2°C);
3. the unit is connected to a blanket, and the Medi-Therm II has
been set to 39.2°F (4°C) in manual mode;
4. the reservoir water temperature is 40°F (4.4°C); and,
5. the pressure check is performed with a gauge manifold connected
to the system with flexible hoses.
Upon completion of the pressure check, turn the unit off and allow
refrigerant in the manifold and hoses (especially the high side) to migrate
back into the unit before closing the service valves and disconnecting the
hoses. Warming the hose near the service valve with your hands for 2-3
minutes will ensure this.
• If recharging is required, most likely there is a leak in the system. Locate and
repair any leaks before recharging the unit.
• Replace the two service valve caps and two gage port caps after servicing the
refrigeration system.
After servicing the refrigeration unit, make sure to perform the FUNCTIONAL
CHECK AND SAFETY INSPECTION (see section 7.3).
9.1.2 R-134a SYSTEMS
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