3 water-cooled scw series startup – Sterlco S Series Central Chilling Stations User Manual

Page 36

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SCW Series Central Chilling Stations

2. Close the gauge cock leading to the pump suction and

open the gauge cock leading to the pump discharge.

3. Close the discharge butterfly valve, crack it open, then

start the pump and observe the gauge.

• If the gauge indicates within 15 psi (103.4 kPa/1.03

bars) below the pump curve, pump rotation is
correct. Pump rotation is clockwise opposite the
shaft end
.

• If the gauge indicates 20 psi (137.9 kPa/1.38 bars)

or more below the pump curve, the pump is running
backwards. Reverse rotation by interchanging any
two power mains to the pump motor or starter.

• Recheck the pressure to be sure it increased.

; Check the water level in the pump tank to be sure the pump

does not run dry while the system piping is being filled.

; Check your work and proceed to the Startup procedure.

5-3 Water-Cooled SCW Series Startup

1. Start the chiller by pushing the

Start

button on the control

panel of the unit.

2. The screen will display the Main Menu screen.

3. If your chiller has been setup to control the pump tank, the

recirculation pump will turn on first, then after 5 seconds
the process pump will turn on. If configured with a standby
pump, the lead/lag will control which pump turns on.

4. Fifteen (15) seconds after the last pump turns on the first

compressor will turn on. Based on the temperature of the
water, the controller will turn on compressors every 15
seconds.

5. Adjust the Freezestat cut-out, located in the main electrical

enclosure, to 10°F (6ºC) below the process temperature set
point you want.

Note: If the recirculation pump does not turn on (or that the flow switch is not satisfied) the

compressors will not be allowed to turn on.

6. Check the pump(s) amp draws and pressures. The amp

draws must be within the pump(s) running load and service
factor amps.

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