16
7.4 - 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 guideline, and does
not make Carrier in any way liable. After wire sizing has been
completed, using the certified dimensional drawing, the instal-
ler 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 accessory system the following standardised installa-
tion methods are used, in accordance with IEC 60364, table
52C:
-
No.17: suspended aerial lines, and No. 61: buried conduit
with a derating coefficient of 20.
The calculation is based on PVC or XLPE insulated cables
with copper or aluminium core. The maximum temperature is
48°C. 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.
The current values used are given for a unit equipped with a
hydronic kit operating at maximum current.
7.4.1 - power cable entry
The power cables can enter the 30RQ control box from below
or from the unit side.
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 (e.g.on a concrete base): It is
recommended to enter the power cables from the control
box side. An aluminium plate on the control box face
allows introduction of the cables.
It is important to check that the power cable bend radius is
compatible with the connection space available in the control
box. Refer to the certified dimensional drawing for the unit.
Table of minimum and maximum wire sections for connection to 30RQ units
Max. connectable
Min. wire section
Max. wire section
section
30RQ section (mm
2
)
section (mm
2
)
Max. length (m)
Wire type
section (mm
2
)
Max. length (m)
Wire type
262
1 x 240 or 2 x 150
1 x 95
178
XLPE Cu
2 x 95
260
XLPE Al
302
2 x 240
1 x 120
197
XLPE Cu
2 x 120
280
XLPE Al
342
2 x 240
1 x 120
185
XLPE Cu
2 x 150
300
XLPE Al
372
2 x 240
1 x 150
188
XLPE Cu
2 x 185
315
XLPE Al
402
2 x 240
1 x 185
190
XLPE Cu
2 x 240
330
XLPE Al
432
3 x 240
1 x 185
190
XLPE Cu
2 x 240
330
XLPE Al
462
3 x 240
1 x 240
205
XLPE Cu
3 x 185
395
XLPE Al
522
3 x 240
2 x 95
190
XLPE Cu
3 x 240
415
XLPE Al
NOTE:
The current values used are given for a unit equipped with a hydronic kit operating at maximum current.
Supply cable inlet
7.5 - Field control wiring
Refer to the 30RB/RQ Pro-Dialog Plus Controls IOM and the
certified wiring diagram supplied with the unit for the field
control wiring of the following features:
•
Customer interlock (safety chain)
•
Water heat exchanger pump interlock (mandatory)
•
Remote on/off switch
•
Remote heat/cool switch
•
Demand limit external switch 1
•
Remote dual set point
•
Alarm report by circuit
•
Water heat exchanger pump control
•
Remote set point reset or outside air temperature sensor
reset (0-10 V)
•
Various interlocks on the Energy Management Module
(EMM) board (accessory or option)
7.6 - Power supply
After the unit has been commissioned, the power supply must
only be disconnected for quick maintenance operations (one
day maximum). For longer maintenance operations or when the
unit is taken out of service and stored (e.g. during the winter or
if the unit does not need to generate cooling) the power supply
must be maintained to ensure supply to the compressor oil
crankcase heaters.
7.4.2 - Connection extension box
This accessory permits stripping the power cables before they
enter the control box, and it must be used when the cable bend
radius is not compatible with the connection space available in
the control box. The accessory connection extension box
ensures mechanical protection of the stripped cable, before it
enters the control box. It must be used in the following cases:
-
Unit placed on the ground and use of power cables with
protective metallic armour.
-
Unit placed on the ground and use of power cables with a
section > 250 mm
2
.
