Thermo Scientific XBF40-MD Series Installation, Operation And Service Manual page 43

Thermo Scientific XBF40-MD Series Blast Freezers
REMOVE THE COMPRESSOR
1. Cut Suction and Discharge lines to the failed compressor.
2. Remove the compressor mounting bolts.
3. Remove the cover from the electrical junction box on the side of the
compressor. Label and disconnect the power leads.
4. Remove the compressor from of the machine compartment.
5. Test a sample of the compressor oil. If non-acidic, no backflush would
be required. If there is an acid condition (see BACKFLUSH
PROCEDURE) and follow the procedure to backflush the evaporator,
condenser, and all of the tubing; the compressor, accumulators,
expansion tanks, TXV and tubing that cannot be flushed MUST be
replaced.
INSTALL THE NEW COMPRESSOR
CAUTION: Replacement compressors are pressurized with nitrogen and
may only be installed by qualified refrigeration technicians. Also, while
brazing in the replacement components, a very low purge of dry nitrogen
must be applied to reduce oxidation from occurring during the brazing
procedure. Purge the nitrogen through the system or components during
brazing and allow it to vent from the open port through the manifold.
6. Mount compressor on base and reinstall rubber feet and bolts.
7. Braze the suction and discharge tubing to the new compressor. Also
install any of the other components that may have been replaced if there
was an acid condition.
8. Install process tube fittings to the end of the process tubes for evacuation
and recharging.
Installation, Operation and Service Manual
Appendix
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