Parker Hyperchill PCW420, User Manual

   English

3/8

PCW420-650

The specifi c weight values at different temperatures for glycol percent-
age values are given in the table.

%

glicol

Temperature [°C]

-10

0

10

20

30

40

50

0%

1.0024

1.0008

0.9988

0.9964

0.9936

0.9905

0.9869

10%

1.0177

1.0155

1.0130

1.0101

1.0067

1.0030

0.9989

20%

1.0330

1.0303

1.0272

1.0237

1.0199

1.0156

1.0110

30%

1.0483

1.0450

1.0414

1.0374

1.0330

1.0282

1.0230

!

 Caution: When fi lling the system, take into account the ca-

pacity of the expansion vessel as well.

3.4 Electrical circuit

3.4.1 

Checks and connections

!

 Before carrying out any operation on the electrical system, make 

sure that the appliance is disconnected from the electrical power sup-
ply.
All electrical connections must comply with the applicable regulations 
in force in the country of installation.

Initial checks

1) The power supply voltage and frequency must correspond to the 

values stamped on the chiller nameplate. The power supply charac-
teristics must not deviate, even for brief periods, from the tolerance 
limits indicated on the electrical diagram , which are +/- 10% for the 
voltage; +/- 1% for the frequency.

2) The power supply must be symmetrical (the effective voltages and 

the phase angles of consecutive phases must be equal). The maxi-
mum permissible voltage imbalance is 2%.

Connection

1) The electrical power supply must be connected to the chiller using a 

4-wire cable, comprising 3 phase conductors and an earth conduc-
tor, with no neutral. For minimum cable section, see par. 7.4.

2) Pass the cable through the cable entry on the rear panel of the ma-

chine and connect the phase and neutral to the terminals of the main 
isolator switch (QS); connect the earth wire to the earth terminal (PE).

3) Ensure that supply cable has at its source protection against direct 

contact of at least IP2X or IPXXB.

4) On the supply line to the chiller, install a residual-current circuit 

breaker with a trip rating of (RCCB - IDn = 0.3A), with the current 
rating indicated in the reference electrical diagram, and with a short 
circuit current rating appropriate to the short circuit fault current 
existing in the machine installation area. 
The nominal current In of the magnetic circuit breaker must be equal 
to the FLA with an intervention curve type D.

5) Max. grid impedance value = 0.274 ohm.

Subsequent checks

Check that the machine and the auxiliary equipment are earthed and 
protected against short circuit and/or overload.

!

 Once the unit has been connected and the upstream main switch 

closed (thereby connecting the power supply to the machine), the 
voltage in the electrical circuit will reach dangerous levels. Maximum 
caution is required!

3.4.2 General 

alarm

All the chillers are equipped with an alarm signalling system (see electri-
cal diagram), comprised of a switching free contact in a terminal block: 
this may be used for the connection of an external audible or visual 
alarm, or used to provide an input signal for a logic control system such 
as a PLC.

3.4.3 ON/OFF 

remoto

All the chillers can be connected to a remote ON/OFF control.
See the electrical diagram for the connection of the remote ON-OFF 
contact.

3.5  Centrifugal version (C)

Used when ducting of the hot air coming from cooling is required.
In fact, the centrifugal fans are able to give the air a useful static pres-
sure that overcomes the pressure losses due to ducting.
Important: Units equipped with centrifugal fans cannot be installed in 
open air without ducting. To work correctly, the centrifugal fans require 
a minimum counterpressure preventing the electric motor from ”over-
revving” and its consequent breaking.

Rules for ducting

1) Each fan must be individually ducted: the fans must be able to work 

independently.

2) The ducting must have air fl ow are as equal to those of the fans 

installed on the unit.

3.6  Water-cooled version (W)

In the water-cooled version, the chillers require a water circuit that 
takes the cold water to condenser.
The water version chiller is equipped with a pressure regulating valve 
at the condenser inlet, whose function is to regulate the water fl ow in 
order to always obtain optimum condensation.

Preliminary checks

If the water supply to the condenser is by means of a closed circuit,
perform all the preliminary checks listed for the main water
circuit (para. 3.3.1).

Connection

1) It is advisable to equip the cooling water circuit with shutoff valves, 

enabling the machine to be cut out in case of maintenance.

2) Connect the water delivery/return pipes to the special connections 

located on the back of the unit.

3) If the cooling water is “expendable” it is advisable to equip the 

circuit with a fi lter at the condenser inlet, in order to reduce the risk 
of the surfaces becoming dirtied.

4) If the circuit is of the closed type, make sure it is fi lled with water 

and the air properly vented.