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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
Standard:
- 30XAV 0500 to 0700 units have one connection point.
- 30XAV 0800 to 1150 units have two connection points
(one with option 81).
18
Motor
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 Carrier 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 of 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;
arrangement 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 phase rotation 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 30XAV control box from
below or from the unit side: refer to unit drawings. For 30XAV
unit sizes 500 to 1150 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 support
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.
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