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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
unit nameplate. The supply voltage must be within the range
specified in the electrical data table. For connection details
refer to the wiring diagrams.
WARNING: Operation of the unit 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 supplier at once and ensure that the unit 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 V; 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 - Power connection/disconnect switch
Units
Connection points
30XW 252-862
1 per unit
30XW 1002-1762
1 for circuit A
1 for circuit B
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 the
second column of the table on the next page.
The calculations for favourable and unfavourable cases are
based on the maximum current for each unit (see electrical
data tables). The design uses the standardised installation
methods in accordance with IEC 60364: multiconductor
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 42°C. The given
maximum length is calculated to limit the voltage drop to 5%.
Electrical data notes and operating conditions, 30XW units
• As standard:
30XW 254 to 862 units have a single power connection point located
immediately upstream of the main disconnect switch.
30XW 1002 to 1762 units have two connection points located immediately
upstream of the main disconnect switches.
• The control box includes the following standard features:
- One main disconnect switch per circuit*
- Starter and motor protection devices for each compressor
- Anti-short cycle protection devices*
- Control devices
• Field connections:
All connections to the system and the electrical installations must be in full
accordance with all applicable codes.
• The Carrier 30XW units are designed and built to ensure conformance with
local codes. The recommendations of European standard EN 60204-1
(corresponds to IEC 60204-1) (machine safety - electrical machine
components - part 1: general regulations) are specifically taken into account,
when designing the electrical equipment.
• The absence of power supply disconnect switch(es) and short-cycle protection
devices in option 82A is an important factor that has to be taken into considera-
tion at the installation site.
Units equipped with one of these two options are supplied with a declaration of
incorporation, as required by the machinery directive.
Notes:
• Generally the recommendations of IEC 60364 are accepted as compliance
with the requirements of the installation directives. Conformance with EN
60204-1 is the best means of ensuring compliance with the Machines Directive.
• Annex B of EN 60204 1 describes the electrical characteristics used for the
operation of the machines.
1. The operating environment for the 30XW units is specified below:
• Environment** Environment as classified in EN 60721 (corresponds to IEC 60721):
- indoor installation
- ambient temperature range: minimum tempe5°C to +42°C, class
AA4
- altitude: lower than or equal to 2000 m
- presence of water: class AD2 (possibility of water droplets)
- presence of hard solids, class 4S2 (no significant dust present)
- presence of corrosive and polluting substances, class 4C2 (negligible)
- personal skills: BA4 (informed person)
2. Power supply frequency variation: ± 2 Hz.
3. The neutral (N) line must not be connected directly to the unit (if necessary use
a transformer).
4. Overcurrent protection of the power supply conductors is not provided with the
unit.
5. The factory installed disconnect switch(es)/circuit breaker(s) is (are) of a type
suitable for power interruption in accordance with EN 60947-3 (corresponds to
IEC 60947-3).
6. The units are designed for connection to TN networks (IEC 60364). For IT
networks the earth connection must not be at the network earth. Provide a local
earth, consult competent local organisations to complete the electrical installation.
NOTE: If particular aspects of an actual installation do not conform to
the conditions described above, or if there are other conditions which
should be considered, always contact your local Carrier representative.
* Not provided for units equipped with option 82A
** The required protection level for this class is IP21B or IPX1B (according to
reference standard IEC 60529). All 30XW units fulfil this protection condition. In
general the casings fulfil class IP23 or IPX3B.
Motor
A
B
C
