6.Protect new valve body from heat while brazing with plastic heat sink (Thermo Trap) or wrap valve body with wet rag.
7.Fit all lines into new valve and braze lines into new valve.
WARNING
EXPLOSION HAZARD
The use of nitrogen requires a pressure regulator. Follow all safety procedures and wear protective safety clothing etc.
Failure to follow proper safety procedures could result in serious injury or death.
8.Pressurize sealed system with a combination of
9.Once the sealed system is leak free, install solenoid coil on new valve and charge the sealed system by weighing in the proper amount and type of refrigerant as shown on rating plate. Crimp the process tubes and solder the ends shut. Do not leave Schrader or piercing valves in the sealed system.
NOTE: When brazing a reversing valve into the system, it is of extreme importance that the temperature of the valve does not exceed 250°F at any time.
Wrap the reversing valve with a large rag saturated with water.
The wet rag around the reversing valve will eliminate conduction of heat to the valve body when brazing the line connection.
COMPRESSOR CHECKS
WARNING
ELECTRIC SHOCK HAZARD
Turn off electric power before service or installation. Extreme care must be used, if it becomes necessary to work on equipment with power applied.
Failure to do so could result in serious injury or death.
Locked Rotor Voltage (L.R.V.) Test
Locked rotor voltage (L.R.V.) is the actual voltage available at the compressor under a stalled condition.
Single Phase Connections
Disconnect power from unit. Using a voltmeter, attach one lead of the meter to the run “R” terminal on the compressor and the other lead to the common “C” terminal of the com- pressor. Restore power to unit.
Determine L.R.V.
Start the compressor with the volt meter attached; then stop the unit. Attempt to restart the compressor within a couple of seconds and immediately read the voltage on the meter. The compressor under these conditions will not start and will usually kick out on overload within a few seconds since the pressures in the system will not have had time to equalize. Voltage should be at or above minimum voltage of 197 VAC, as specifi ed on the rating plate. If less than minimum, check for cause of inadequate power supply; i.e., incorrect wire size, loose electrical connections, etc.
Amperage (L.R.A.) Test
The running amperage of the compressor is the most impor- tant of these readings. A running amperage higher than that indicated in the performance data indicates that a problem exists mechanically or electrically.
Single Phase Running and L.R.A. Test
NOTE: Consult the specifi cation and performance section for running amperage. The L.R.A. can also be found on the rating plate.
Select the proper amperage scale and clamp the meter probe around the wire to the “C” terminal of the compressor.
Turn on the unit and read the running amperage on the me- ter. If the compressor does not start, the reading will indicate the locked rotor amperage (L.R.A.).
Overloads
The compressor is equipped with an external overload which senses both motor amperage and winding temperature. High motor temperature or amperage heats the overload causing it to open, breaking the common circuit within the compressor.
Heat generated within the compressor shell, usually due to recycling of the motor, is slow to dissipate. It may take any- where from a few minutes to several hours for the overload to reset.
Checking the Overload
WARNING
ELECTRIC SHOCK HAZARD
Turn off electric power before service or installation. Extreme care must be used, if it becomes necessary to work on equipment with power applied.
Failure to do so could result in serious injury or death.
36
