EWYQ080~250DAYN
Packaged air-cooled water chillers
4PW35559-1D – 03.2011
Installation manual
7
Power circuit and cable requirements
1
The electrical power supply to the unit must 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 (high speed type 100 mA rated). Recommended
fuses are mentioned on the wiring diagram supplied with the
unit. For a system with chillers in a DICN configuration, be sure
to provide a separate power circuit for every chiller.
Connection of the air-cooled water chiller power supply
1
Using the appropriate cable, connect the power circuit to the L1,
L2 and L3 terminals of the unit.
The power circuit must be connected to the terminals 2, 4 and 6
of the main isolator switch.
2
Connect the earth conductor (yellow/green) to the earthing
terminal .
Interconnection cables
■
Only for models without option OPSP, OPTP, OPHP, OPSC
or OPTC
■
Voltage free contacts (for all models)
The controller is provided with voltage free contacts to indicate
the status of the unit. These voltage free contacts can be wired
as described on the wiring diagram.
■
Remote inputs (for all models)
Besides the voltage free contacts, there are also possibilities to
install remote inputs. They can be installed as shown on the
wiring diagram.
For units in DICN configuration, note the following:
•
Switch for remote on/off:
Units with status
NORMAL
or
STANDBY
will be controlled
by the remote on/off switch connected to the chiller defined
as
MASTER
.
Units with status
DISCONNECT ON/OFF
are controlled
by the switch connected to them.
See also operation manual: "Selecting local or remote on/off
control".
•
Remote dual setpoint switch:
The remote dual setpoint switch may only be connected to
the chiller defined as
MASTER
.
However in case the master drops out because of e.g. a
power supply failure, it might be interesting to have the dual
temperature switch installed to the other units as well.
Connecting field wiring
The routing of the field wiring must be as indicated in the figures
below.
In the cover plate some free space is provided to install the
appropriate nipples (drilling through the cover plate is required),
-
for single circuit units: located below the field wiring
terminals,
-
for double circuit units: located below the mainswitch.
Strap the wiring with a clamp (field supply) to the attachment plugs
(1) as shown in the figures below to ensure strain relief of the wiring.
■
Power supply of factory mounted heater tape (option OP10)
and additional heater tapes.
An independent power supply 1~50
Hz, 230
V must be
connected to the terminals as indicated on the wiring diagram
supplied with the unit. The heater tapes must be connected to
the independent power supply year-round. Separate fuses and a
heater tape isolator switch must be installed in the field. Connect
the earth conductor (yellow/green) to the earthing terminal
.
(Refer to the wiring diagram supplied with the unit.)
Use a power supply cable containing 2 conductors and ground
with a cable section in function of:
■
maximum current of 10 A,
■
maximum ambient temperature of 60°C inside the switchbox.
Switch off the main isolator switch before making any
connections (switch off the circuit breaker, remove or
switch off the fuses).
A pump interlock contact must be installed to prevent
the unit from operating without water flow. A terminal
is provided in the switchbox for the electrical
connection of the interlock contact.
For units in a DICN configuration, every chiller can
either have an individual circulation pump or 1 pump
can discharge water in a distributor that leads water to
several chillers.
In both cases, all units must be equipped with an
interlock contact!
NOTE
Normally the unit will not operate if there is no flow
thanks to the standard installed flow switch.
But as to have a double safety, you
must
install
the pump interlock contact.
Operating the unit without flow will result in very
severe damage to the unit (freezing of the
evaporator).
NOTE
In case mechanical stress occurs on the wiring, the
earthing connections may not become loose before
current-carrying connections do. Therefore make the
earthing conductors longer than the current-carrying
conductors.
Connection of field wiring to terminals
Pay special attention to markings on the terminals. The
illustration below indicates corresponding positions to feed
field wiring through correctly.
Single circuit unit
1
