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Flooded type water cooled screw chiller (PCB Control)
MCAC-CTSM-2012-11
48
connection bolts of upper/lower terminals of AC contactor, etc.) are firmly fixed.
9) Inspect the connections in the electrical cabinet for looseness, especially the electric part in the
cabinet. The parts connected by bolts might be loose due to transportation. If there is any
looseness, tighten it to avoid burnout of circuit or element caused by poor contact.
Inspect the terminals for looseness and poor contact caused by vibration and collision during
transportation and installation (especially the electric part; ensure the connection points of all
terminals are firm and reliable before electrification).
Inspect whether there is poor contact and short circuit caused by dust, moisture, etc. in the
electrical cabinet, and whether the values of all temperature sensors are normal. During the
shutdown of the machine, the indicated temperatures of discharge, fin, and the environment
shall be almost the same, and the entering and leaving chilled water temperatures shall be
almost the same.
10) Before the unit leaves the factory, the control cabinet is well connected with main motor,
electrical actuator, and sensor elements of pressure temperature, etc. Therefore, the wiring on
site for the user is very simple. Only the chilled water flow switch line and chilled water pump
linked control line (control contact is active) need to be connected. For the detailed connection
way, please refer to the circuit wiring diagram in the operation manual for the unit. (The
attached circuit diagram represents the case of air-cooled heat pump unit for user’s reference,
as for the details, the operation manual supplied with the unit shall be final.)
11) Target-type flow control is set on the chilled water pipeline which shall be installed at the chilled
water outlet of the unit. The NO contact of the target-type flow control in the chilled water
system shall be connected to the control circuit as per the wiring diagram.
Note: Disordered water flow may lead to wrong action of the flow switch; therefore, the control
cabinet will command the unit to stop after receiving continuous disconnection signals during
10 s.
12) The tube where the temperature sensing probe is installed shall be filled with lubricating oil or
other grease that will not freeze at the temperature of the leaving chilled water for the
All connection points
of terminals must be
firm and reliable.
Inspect all terminals
for firmness and
reliability before
electrification.