EWWD440~850AAYNNO**
Packaged water-cooled water chillers
4PW25558-1B
Installation and operation manual
11
Power circuit and cable requirements
1
The electrical power supply to the unit should be arranged so
that it can be switched on or off independently of the electrical
supply to other items of the plant and equipment in general.
2
A power circuit must be provided for connection of the unit. This
circuit must be protected with the required safety devices, i.e. a
circuit breaker, a slow blow fuse on each phase and an earth
leak detector. Recommended fuses are mentioned on the wiring
diagram supplied with the unit.
Connection of the watercooled water unit power supply
1
Using the appropriate cable, connect the power circuit to the L1,
L2 and L3 terminals of the unit.
2
Connect the earth conductor (yellow/green) to the earthing
terminal PE.
Interconnection cables
■
Voltage free contacts
The controller is provided with some voltage free contacts to
indicate the status of the unit. These voltage free contacts can
be wired as described on the wiring diagram. The maximum
allowable current is 3 A.
■
Remote inputs
Besides the voltage free contacts, there are also possibilities to
install remote inputs. They can be installed as shown on the
wiring diagram.
Switch off the main isolator switch before making any
connections (switch off the circuit breaker, remove or
switch off the fuses).
■
In addition to the power supply cable, a cable
must be provided for the connection of the pump
interlock.
Be sure to interlock so, that the compressor will
not come into operation unless the waterpump is
operated. For this purpose 3 spare terminals are
provided in the switch box. Refer to the wiring
diagram supplied with the unit.
■
Improper installation of this interlock can result in
severe damage of the equipment.