Flooded type water cooled screw chiller (PCB Control)
87
VI. Commissioning
1.
Pre start-up
(1) Electrical System Inspection
1) Inspect whether power distribution capacity is compliant with the power of the unit before the first
start-up, and whether the diameter of the selected cable can bear the maximum working current of the
master compressor.
The max economical conveying distance:
The max loading time in a year
（
h
）
Copper core length(m)
<3000h
264
3000
～
5000h
294
>5000h
331
2) Inspect whether the electric mode is compliant with that of the unit, three-phase five-line (three phase
lines, one zero line and one earth wire, 380V±10%).
3) Inspect whether the maximum phase voltage unbalance is compliant with the requirement, 2% for the
maximum permissible phase voltage unbalance and 5% for the phase current balance. The machine
must not be started up when the phase voltage unbalance exceeds 2%. If the measured unbalance% is
excess, the power supply sector shall be informed of immediately.
4) Inspect whether the supply circuit is the compressor is firmly and properly connected, and tighten it if
there is any looseness. The screws might be loose due to the factors such as long-distance transport
and hoisting of the master compressor. Or, the electrical elements (e.g. air switch, AC contactor, etc.) in
the control cabinet of the master compressor and the compressor might be damaged.
5) Carefully inspect all the electrical lines with a multimeter, and whether the connections are properly
installed. Carry out measurement in mega ohm and ensure that there is no short circuit at the shell.
Inspect whether the earth wire is properly installed, and whether the insulation resistance to ground
exceeds 2MΩ. And inspect whether the supply line meets the requirement of capacity.
6) Inspect whether disconnection switch is installed to the supply line of the supply unit.
7) Carry out complete inspect for all connections of the main circuit in the control cabinet and all external
connections of the control circuit before power connection (e.g. oil heater, compressor electronic
protection, circulatory water temperature sensor, target-type flow switch connection, water pump linked
control, communication line connection, etc.); inspect the bolts of the wiring terminal for looseness.
Inspect whether various electric meters and appliances are properly installed, complete and available.
Inspect the interior and exterior of the electrical cabinet, especially various wiring ports, for cleanness. If
the communication lines of the PCB and control screen are damaged, refer to the diagram below.
8) After the inspection for all the above items is complete, connect the control cabinet and the supply
indication lamp will light up, indicating that the oil heater is working. Observe whether the phase loss
protection is in normal condition, if it is (green light on), close the single-pole switch in the control cabinet,
then the control circuit begins working, and the touch screen and PCB control are put into operation.
