Dimensioning the protective conductor
Observe the local regulations for protective conductors subject to an increased leakage current
at the site of operation.
/
/
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3(
①
Protective conductor for line feeder cables
②
Protective conductor for inverter line feeder cables
③
Protective conductor between PE and the control cabinet
④
Protective conductor for motor feeder cables
The minimum cross-section of the protective conductor
①
…
④
depends on the cross-section
of the line or motor feeder cable:
● Line or motor feeder cable ≤ 16 mm
2
⇒ Minimum cross-section of the protective conductor = cross-section of the line or motor
feeder cable
● 16 mm² < line or motor feeder cable ≤ 35 mm
2
⇒ Minimum cross-section of the protective conductor = 16 mm
2
● Line or motor feeder cable > 35 mm
2
⇒ Minimum cross-section of the protective conductor = ½ cross-section of the line or motor
feeder cable
Additional requirements placed on the protective conductor
①
:
● For permanent connection, the protective conductor must fulfill at least one of the following
conditions:
– The protective conductor is routed so that it is protected against damage along its
complete length.
Cables routed inside switch cabinets or enclosed machine housings are considered to
be adequately protected against mechanical damage.
– As a conductor of a multi-conductor cable, the protective conductor has a cross-section
≥ 2.5 mm² Cu.
– For an individual conductor, the protective conductor has a cross-section ≥ 10 mm² Cu.
– The protective conductor consists of two individual conductors with the same cross-
section.
● When connecting a multi-core cable using an industrial plug connector according to EN
60309, the protective conductor must have a cross-section of ≥ 2.5 mm² Cu.
Installing
4.8 Connect the line supply, motor and braking resistor
SINAMICS G120C converter
68
Operating Instructions, 09/2017, FW V4.7 SP9, A5E34263257B AF
