4.0 OPERATION
4.4 TEMPERATURE SETTING
Normally the temperature setting for,
a.) Cooling is 75-80°F
b.) Heating is 70°F ( If heating coil is available ).
4.5 PHASE ROTATION
If during initial start up the compressor does not build up pressure, noise is abnormally load
and power consumption is minimal, then there is a possibility that the unit is operating in
reverse rotation. Shut down the power connection and connect wire to the proper terminals.
4.6 CYCLE LIMIT RATE
Each compressors must not be cycle on-off for more than 12 times per hour. The higher
number of starts per hour will reduce the life of the compressor. Thus, it is suggested that anti
short cycle timer is provided in the system.
4.7 HOT GAS BYPASS
The purpose of the hot gas by pass is to create artificial load in the system by means of
injecting hot gas into the inlet of the distributor. This would prevent the suction pressure from
falling below the desired settings and thus causing frequent compressor cycling. The valve is
pressure actuated, where it allows the discharge gas to bypass if the downstream pressure is
below the setting. The setting could be
changed by adjusting the stem on the
valve body. To set the pressure, loose the
seal nut as shown below and turn the
adjusting stem clockwise to raise the
pressure or counter clockwise to lower the
pressure. One turn of the stem equals to
16psig. The adjustment range for the valve
is between 10” hg to 120psig.
It is important that the setting to be
performed under actual operating
condition, i.e. under minimal system load
conditions so that it could maintain the
minimum desired suction pressure. Hot
gas flow could be detected by listening the
gas flowing through the valve or by
touching the outlet pipe.
