Wiring Installation - Midea LSBLG MCF Series Technical & Service Manual

Flooded type water cooled screw chiller (MIC)
actual operating current is satisfactory.
24) Inspect whether the water replenishing device for the expansion tank is smooth, and that 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.
25) Adjust the flow and inspect whether the water pressure drop of the evaporator meets the
requirements of the unit's normal operation. The pressure at the chilled water inlet and outlet of
the unit must be kept at least 0.2 MPa.
26) The total water quantity in the system should be sufficient to prevent frequent "on-off" cycling. A
reasonable minimum quantity allows for a complete water system turnover in at least 15
minutes.
3.

Wiring installation

WARNING: To prevent any accidents during wiring, cut the power before connecting 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, find and correct any faults
Copper wire is required for all supply lines in field connections to avoid corrosion and overheating at the
connection of terminals. The lines and control cables must be separately paved and equipped with
protective pipes to avoid intervention of supply lines in control cable.
Power section: Connect the power supply cable to the control cabinet, when it arrives at the jobsite. The
power supply cable is connected to the terminals of L1, L2, L3, N and PE and the terminals need to be
fixed again after 24h running (the minimum allowed time). Please seal the entering wiring hole after
users installed the main power wires, in order to avoid the dust entering into electric control cabinet.
Caution: it is suggested that to use appropriate tools to make sure that a enough height to install the
main power wires if the basement is higher than 200 mm. Breaking isolation switches should be added
between the power cord of users and the unit. The capacities of the breaking isolation switches
recommended are electric control.
(1) Attention: refrigerant selection: the previous software settings are replaced by the current hardware
settings to avoid a software error wrongly selecting refrigerant and damaging the unit.
(2) To avoid incorrect control in field connection, the liquid control circuit (24 V) must not be in the same
conduit with the lead wire with a voltage higher than 24 V.
(3) The control circuits of various units are all 220 V. For the wiring of the control circuits, refer to the wiring
diagrams supplied with the units.
(4) A unit consists of a master compressor and slave compressor communicating via shield wire protected
by sleeve and paved separately from supply line.
(5) The control output cable to be connected on site shall be AC250V-1mm2, and 0.75mm
must be used for control signal line.
80
MCAC-CTSM-2018-1
2
shield wire (24 V)