Sterlco S Series Central Chilling Stations - Manual (Page 26)

Page 26 of 77 SCW Series Central Chilling Stations
• No steam, hot air or fume exhausts drawn into the condenser
coils.
• Service accessibility.
SCW Series condensing pressure
with 95ºF (35ºC) condenser air
R-134a = 171 psi (1,179 kPa/11.79 bars)
Note: Due to the variables involved in remote air-cooled condenser installations, no set or
standard piping procedure exists. Each installation must be designed and installed by
qualified persons. Follow the instructions supplied with the condenser.
3-11 Checking Motor Direction
Compressor
Check Compressor Rotation Before Starting Unit!
1. Connect a phase monitor and phase incoming power ABC.
2. Connect a refrigerant gauge to the suction service valve. Fully front seat
the service valve and open one full turn.
3. Bump start the compressor by switching off then on quickly 0.5 to 1
second. If the rotation is correct, the suction pressure will drop
immediately. A rise in pressure will indicate the wrong rotation. If this
occurs, change over two electrical phases of the incoming power supply
(do not change phase at the compressor starter).
Note:
• Never switch contactor leads or motor leads for reversing
rotation.
• Do not use contactor or motor leads for phase matching.
• Compressor damage will occur if the compressor is run in
reverse. The compressor motor protector checks for correct
phasing and will not allow it to start in reverse.
• If you discover that compressor rotation is reversed, correct it
by switching any two main power leads into the disconnect
switch or distribution block on the unit.
Water Pump
A positive pressure of 20 to 30 psi (137.9 to 206.8 kPa/1.38 to 2.07
bars) on the
TO PROCESS line indicates correct pump rotation.