D Series Modular Air-cooled Scroll Chillers
36
7.3 Trial Run
See the operation manual of the applicable controller for more details.
(1)
When the unit has not been used for a long period or the ambient temperature is quiet low, keep the
unit energized 8 hours before startup to preheat the crankcase of the compressor so as evaporate
the liquid refrigerant inside the compressor which otherwise would cause adverse effect on the
compressor.
(2)
Be sure valves are opened properly to prevent the compressor from being damaged by the abnormal
high pressure.
(3)
Carefully adjust the flow control valve and the shutoff valve of the chilled water system to make the
flow rate meet the rated value on the nameplate.
(4)
Turn on the wired controller to check the error record. If any error exists, eliminated it before restarting
the unit.
(5)
When the trial run takes 30 minutes and the entering/leaving water temperature approaches the
regulated range, It is able to set the entering/leaving water temperature based on the actual load. The
unit should be restarted at least 10 later after the shutdown. Then, check the set points of the controls
in accordance with the instructions of the control system.
WARNING
•
During flushing, be sure the control panel on the main unit is disabled to start/stop the water pump.
•
Do not start up the unit before the water system has not yet been drained up.
•
Do not restart the unit when the unit has been stopped less than for 6 minutes.
7.4 Routine Startup/Shutdown
It is recommended to start the system through the wired controller in the sequence of the water pump first
and then the main unit, and stop the system in a reverse sequence. Remember to keep the unit energized 8
hours before startup to preheat the crankcase of the compressor so as evaporate the liquid refrigerant inside
the compressor which otherwise would cause adverse effect on the compressor.
NOTE
•
When the water temperature is lower than 15~20
℃
, do not start the terminal equipment until the water
temperature reaches higher than 35
℃
for guaranteeing a sound and reliable operation.
7.5 Maintenance during Long-term Downtime
When the chiller is going to be stopped for a long period, maintenance listed below shall be performed
:
(1) Take the leakage test for the refrigerant tube. If leakage occurs, eliminate it.
(2)
Maintain the water pump and air conditioning divides in accordance with the suggestions provided by
the manufacturer.
(3)
Drain the water system by opening the discharge valve (especially in winter) to avoid frostbite on the
shell and tube.
(4)
Switch off the power supply of the chiller and the water pump.
(5) Clean and dry the inside and outside surface of the chiller. Then, cover it against dust.
7.6 Startup after Long-term Shutdown
Preparations shall be taken when starting up the chiller which has not been used for a long period.
(1) Completely check and clean up the chiller.
(2)
Clean the water piping system.
