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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 therefore acceptable.
5.3 - Power connection/disconnect switch
Units
30XA 0252-1002
30XA
1112, 1212,
1312, 1382,
1402 to 1702
Motor
Connection points
1 per unit
1 for circuit 1
1 for circuit 2
5.4 - 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
column 2 of the table on the next page.
The calculations are based on the maximum machine
current (see electrical data tables).
The calculations for favourable and unfavourable cases are
based on the maximum current for each unit (see electrical
data tables). For the design the standardised installation
methods in accordance with IEC 60364 are used: PVC
(70 °C) or XLPE (90 °C) insulated cables with copper core;
arrange-ment to comply with table 52c of the above standard.
The maximum temperature is 46 °C. The given maximum
length is calculated to limit 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.
5.5 - Power cable entry
The power cables can enter the 30XA control box from
below or from the unit side. For 30XA unit sizes 602 to 1702
the control box that includes the power supply cable connec-
tion 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.
For units with three circuits with option 81 (single power
connection point) the connection must be made from below
the unit.
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.
27
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