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5 - ELECTRICAL CONNECTION
Please refer to the certified dimensional drawings, supplied with
the unit.
5.1 - Power supply
The power supply must conform to the specification on the chiller
nameplate. The supply voltage must be within the range specified
in the electrical data table. For connections refer to the wiring
diagrams and the certified dimensional drawings.
WARNING: Operation of the chiller with an improper supply
voltage or excessive phase imbalance constitutes abuse
which will invalidate the Carrier warranty. If the phase
imbalance exceeds 2% for voltage, or 10% for current, contact
your local electricity supply at once and ensure that the chiller
is not switched on until corrective measures have been taken.
5.2 - Voltage phase imbalance (%)
100 x max. deviation from average voltage
Average voltage
Example:
On a 400 V - 3 ph - 50 Hz supply, the individual phase voltages
were measured to be:
AB = 406 V; BC = 399; AC = 394 V
Average voltage = (406 + 399 + 394)/3 = 1199/3
= 399.7 say 400 V
Calculate the maximum deviation from the 400 V average:
(AB) = 406 - 400 = 6
(BC) = 400 - 399 = 1
(CA) = 400 - 394 = 6
The maximum deviation from the average is 6 V. The greatest
percentage deviation is: 100 x 6/400 = 1.5%
This is less than the permissible 2% and is therefore acceptable.
5.3 - Recommended wire sections
Wire sizing is the responsibility of the installer, and depends on
the characteristics and regulations applicable to each installation
site. The following is only to be used as a guide-line, and does not
make in any way liable. After wire sizing has been completed,
using the certified dimensional drawing, the installer must ensure
easy connection and define any modifications necessary on site.
The connections provided as standard for the field-supplied power
entry cables to the general disconnect/isolator switch are designed
for the number and type of wires, listed in the table below.
The calculations are based on the maximum machine current (see
electrical data tables).
For the design the following standardised installation methods are
used, in accordance with IEC 60364, table 52C:
• For 30XAS units installed outside the building:
No.17: suspended aerial lines
No. 61: buried conduit with a derating coefficient of 20.
The calculation is based on PVC or XLPE insulated cables with
Selection table of minimum and maximum wire sections for connection to 30XAS units
Maximum wire
section
30XAS
Section (mm
242
2 x 150
282
2 x 95
342
2 x 150
442
2 x 150
482
2 x 240
(1)
Power supply wire section (see diagram in chapter 5 'Electrical connection').
Note:
The current values used are given for a unit equipped with a hydraulic kit operating at maximum current.
Minimum calculated section
)
Section (mm
)
Max. length (m)
2
2
(1)
1 x 70
1 x 70
1 x 95
1 x 150
1 x 240
copper core. The maximum temperature is 46 °C for 30XAS units.
The given wire length limits the voltage drop to < 5%.
IMPORTANT: Before connection of the main power cables
(L1 - L2 - L3) on the terminal block, it is imperative to check
the correct order of the 3 phases before proceeding to the
connection on then terminal block or the main disconnect/
isolator switch.
5.4 - Power cable entry
The power cables can enter the control box from below or from
the unit side.
For 30XAS unit sizes 282 to 482 the control box that includes the
power supply cable connection terminal is located in the lower
part of the unit. In this case the control box is raised by 120 mm
compared to the lowest point of the chassis.
The cable entry point depends on the unit configuration:
1. Unit raised from the ground (e.g. installation on sup-port rails):
It is recommended to enter the power cables from below the
control box. A removable aluminium plate below the control
box allows introduction of the cables.
2. Unit placed on the ground: For power cable entry from below
the control box ensure that the cable bend radius is compatible
with the connection space available in the control box. If not,
an aluminium plate on the control box face allows introduction
of the cables.
IMPORTANT: Check the cable bend radius for cable entry into
a control box, located in the lower part of the unit.
Refer to the certified dimensional drawing for the unit.
5.5 - Field control wiring
Motor
IMPORTANT: Field connection of interface circuits may lead
to safety risks: Any control box modification must maintain
equipment conformity with local regulations. Precautions
must be taken to prevent accidental electrical contact between
circuits supplied by different sources:
• The routing selection and/or conductor insulation
characteristics must ensure dual electric insulation.
• In case of accidental disconnection, conductor fixing
between different conductors and/or in the control box
prevents any contact between the conductor ends and an
active energised part.
Refer to the 30XA/30XAS/30XW Touch Pilot control manual and
the certified wiring diagram supplied with the unit for the field
control wiring of the following features:
• Evaporator pump interlock (If present)
• Remote on/off switch
• Demand limit external switch
• Remote dual set point
• Alarm, alert and operation report
• Evaporator pump control
• Heat reclaim condenser pump control (option)
• Hot water valve control (option)
• Set point reset via outside air temperature sensor reset
• Various interlocks on the Energy Management Module
(EMM) board (accessory or option)
Wire type
Section (mm
200
XLPE Cu
190
XLPE Cu
200
XLPE Cu
200
XLPE Cu
250
XLPE Cu
Maximum calculated section
)
Max. length (m)
2
(1)
1 x 240
500
2 x 95
410
2 x 120
435
2 x 185
480
2 x 240
500
Wire type
PVC Cu
PVC Cu
PVC Cu
PVC Cu
PVC Cu
17
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