Flooded type water cooled screw chiller (PCB Control)
86
Power section: It is required to connect the power supply cable to the control cabinet of the unit, 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 see electrical control .
(1) Attention: refrigerant selection: the previous software settings are replaced by the current hardware
settings to avoid the possibility of improper operation of the software leading to wrongly selected
refrigerant and damage to the unit.
(2) In order to avoid wrong control in field connection, the liquid control circuit (24 V) shall not be in the same
conduit with the lead wire with voltage higher than 24 V.
(3) The control circuits of various units are all 220 V, and for the wiring ways of the control circuits, please
refer to the wiring diagrams supplied along with the units.
(4) A unit consists of master compressor and slave compressor communicating via shield wire protected by
sleeve and paved separate from supply line.
(5) The control output cable to be connected on site shall be AC250V-1mm2, and 0.75mm2 shield wire (24
V) shall be used for control signal line.
(6) Attentions: Read the electrical wiring principle diagram and connect the wires strictly according to the
wiring terminal diagram. Three-core shield cable (3×0.75mm2) shall be used for the connection of the
temperature sensor. Common two-core cable (2×0.75mm2) shall be used for the connection of flow
switch to connect to the NO contact of the switch, i.e. the opening point when waterless. Two buttons
can be connected to the external of remote start and stop.
(7) If the customer desires the linked control of the water pump, connect the water pump as shown in the
diagram, where an intermediate relay is required. If the function of linked control of water pump is not
needed, ensure that the water pump is started before starting the machine.
CAUTION: An independent power supply box needs to be equipped with the power supply of the water
pump.
(8) The wiring ports for remote start/stop, flow switch, cool/warm switch, water pump linked control, alarm
indication, etc. are reserved in the electrical cabinet of the unit.
(9) Passive inching button is used for remote start and stop, and the flow switch must be connected to the
NO contact, or the machine cannot be started.
Passive holding switch is used for cool/warm switch, e.g. common selection switch. Controls of large
power electrical appliances such as water pump and user electric heating must be interfaced with a relay,
or the PCB might be burned. Other outputs can be directly connected to indicator lamps or alarms.