Electric Cable Size And Main Fuses - Atlas Copco ga55+ Instruction Book

Instruction book

11.2 Electric cable size and main fuses

Important
IEC versions
For IEC designed control panels, the below suggested cable sections are calculated according to 60364-5-52
electrical installations of buildings, part 5: selection and erection equipment, section 52: current-carrying
capacities in wiring systems.
Standard conditions refer to loose copper conductors or multi-core cable with 70C PVC insulation in free air
or on open cable trays (installation method C) at 30°C ambient temperature and operating at nominal
voltage. The cables may not be grouped with other power circuits or cables.
Worst case conditions refer to:
•
ambient temperature > 30°C.
•
cables in closed raceway, conduit ortrunking system (installation method B2) at 40 °C ambient temperature
•
cables not grouped with other cables
Fuse calculations for IEC are done according to 60364-4-43 electrical installations of buildings, part 4:
protection for safety- section 43: protection against overcurrent. Fuse sizes are calculated in order to protect the
cable against short circuit. Fuse type aM is recommended but gG/gL is also allowed.
9096 3313 00
•
The voltage on the compressor terminals must not deviate more than 10% of the
nominal voltage. It is however highly recommended to keep the voltage drop
over the supply cables at nominal current below 5% of the nominal voltage (IEC
60204-1). If cables are grouped together with other power cables, it may be
necessary to use cables of a larger size than those calculated for the standard
operating conditions.
•
Use the original cable entry. See section Dimension drawings.
•
To preserve the protection degree of the electric cubicle and to protect its
components from dust from the environment, it is mandatory to use a
proper cable gland when connecting the supply cable to the compressor.
•
Local regulations remain applicable if they are stricter than the values proposed
below.
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