Startup; Charging The Refrigeration Side - Hussmann Proto-Aire EZ Manual Del Usuario

Proto-Aire EZ I/O Manual 17

Startup

Charging the Refrigeration Side

Leak Testing
Visually inspect all lines and joints for proper piping practices.
Open Power Supply
Compressors – Open circuit breakers to all compressors.
Isolate
Compressors – Front seat service valves on suction and discharge.
Pressure Transducers – Close angle valves
Liquid Injection Valves – Close Valves
Open
Valves, Receiver.
Verify
Refrigerant requirements for system, compressors, and TXV's in merchandisers and coolers.
Electrical supply and component requirements.
Test Charge
Using properly regulated dry nitrogen and refrigerant mixture, pressurize the system with vapor
only. Bring the system pressure up to 150 psig. Use an electronic leak detector to inspect all
connections. If a leak is found, isolate, repair, and retest. Be sure system is a 150 psig and all
valves closed to repair the leak are re-opened. After the last leak is repaired and retested, the
system must stand unaltered for at least 12 hours with no pressure drop from 150 psig.
Evacuation
Nitrogen and moisture will remain in the system unless proper evacuation procedures are
followed. Nitrogen left in the system may cause excessive head pressure. Moisture causes TXV ice
blockage, wax build up, acid, oil, and sludge formation.
Do not simply purge the system because this procedure is illegal, expensive, harmful to the
environment, and may leave moisture and nitrogen. Do not run the compressor to evacuate
because this procedure introduces moisture into the compressors crankcase oil and does
not produce adequate vacuum to remove moisture from the rest of the system at normal
temperatures.
Setup
Using an 8 CFM or larger vacuum pump, connect to the access port on both the suction header
and liquid supply line of the Proto-Aire EZ Unit. Connect one micron vacuum gauge at the
pump, and one at the furthest point in the system from the compressor. Plan procedures so
breaking the vacuum with refrigerant will not introduce contaminates into the system. The
vacuum pump must be in good condition and filled with fresh oil to achieve desired results.
3090249_D
P/N