Flooded type water cooled screw chiller (PCB Control)
85
checking the leaving evaporator water temperature.
Note: The unit only supplies the ON/OFF signal, but not the 220V power. If a separate
disconnect is used for the 220V supply to the cooler heating cable, it should be clearly marked
so that it is not accidentally shut off during cold seasons.
18)
If the unit is used as a replacement chiller on a previously existing piping system, the system
should be thoroughly flushed prior to unit installation and then regular chilled water analysis
and chemical water treatment is recommended immediately at equipment start-up.
19) Power on the chilled water pump, and inspect its rotation direction. The correct rotation
direction shall be clockwise; if not, re-inspect the wiring of the pump.
20) Start the chilled water pump to circulate water flow. Inspect the water pipelines for water
leakage and dripping.
21) Commission the chilled water pump. Observe whether the water pressure is stable. Observe
the pressure gauges at the pump inlet and outlet, and the readings of the pressure gauges and
the pressure difference between the inlet and outlet change slightly when the water pressure is
stable. Observe whether the operating current of the pump is within the range of rated
operating current; inspect whether the resistance of the system is too large if the difference
between the operating current and rated value is too big; eliminate the system failures until the
actual operating current is satisfied.
22) Inspect whether the water replenishing device for the expansion tank is smooth, and the auto
discharge air valve in the water system enables auto discharge. If the discharge air valve is a
manual type, open the discharge valve of the chilled water pipeline to discharge all air in the
pipeline.
23) Adjust the flow and inspect whether the water pressure drop of the evaporator meets the
requirement of the unit’s normal operation. The pressure at the chilled water inlet and outlet of
the unit shall be kept at least 0.2MPa.
24) The total water quantity in the system should be sufficient to prevent frequent
“on-off” cycling. A
reasonable minimum quantity would allow for a complete water system turnover in not less
than 15 minutes.
3.
Wiring installation
WARNING:
In order to prevent any accident of injury and death during the site wiring , the power supply
shall be cut off before the line is connected to the unit.
Wiring must comply with all applicable codes and ordinances. Warranty is voided if wiring is not in
accordance with specifications. An open fuse indicates a short, ground, or overload. Before replacing a
fuse or restarting a compressor , the trouble must be found and corrected.
Copper wire is required for all supply lines in field connection to avoid corrosion and overheat at the
connection of terminals. The lines and control cables shall be separately paved and equipped with
protective pipes to avoid intervention of supply line in control cable.
