Screw Compressor Central Chiller
Chapter 3: Installation
29
Water-Cooled Central Chiller
1.
Check the shipping papers against the serial tag to be sure chiller size, type and
voltage is correct for the process.
2.
Check the transformer primary voltage connections to be sure they are configured for
the electrical power you are using.
3.
The voltage at the main power connection must be within plus or minus ten percent
(±10%) of the voltage listed on the serial tag.
4.
Phase imbalance must be less than two percent (<2%).
5.
Unit must be wired in sequence (ABC).
6.
Electrical connections must conform to all applicable codes.
7.
Power must be turned on to unit 24 hours prior to start up for the compressor
crankcase heater.
8.
Complete the chilled water
TO
and
FROM PROCESS
connections.
9.
The chilled water supply and return valves on the chiller must be open.
10.
Be sure the pump tank and chilled water circuit are filled with a water/glycol mixture
that provides freeze protection to 20°F (12ºC) below the leaving water temperature
you want.
11.
Complete the tower or city condenser
WATER IN
and
WATER OUT
connections.
Provide an adequate condenser water supply; 2 gpm per ton for city water or 3 gpm
per ton for tower water operation.
12.
Remove all tools, foreign matter and debris from the pump tank reservoir and piping.
13.
Complete all piping leading to and from the pump tank. Observe all applicable codes.
14.
Complete all electrical wiring. Observe all applicable codes.
15.
Tighten all electrical connections.
16.
Prepare all related equipment in the system for operation.
17.
Check for proper compressor rotation direction. To confirm proper rotation:
a.
Connect a phase meter and phase incoming power ABC.
Note:
x
Never switch contactor leads or motor leads for reversing rotation.
x
Do not use contactor or motor leads for phase matching.
x
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.
x
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.
18.
Open the 1” (approx. 25 mm) makeup water valve and allow the tank to fill until the
automatic float valve shuts off. The float level should be adjusted so the standing
water level is 8” (20 cm) from the top of the tank.
