Siemens SINAMICS G120 Hardware Installation Manual page 38

Connecting-up
Danger to life due to fire or electric shock when using unsuitable residual current protection
devices
The inverter can cause a current to flow in the protective conductor. This current can cause
the residual current device (RCD) or residual current monitoring (RCM) to incorrectly trip
(nuisance trip). In the case of a fault (ground fault), the fault current can contain a DC
component, which prevents the RCD/RCM from tripping, with the risk of subsequent fault or
electric shock.
● Use the protection and monitoring devices recommended in the documentation.
Risk of injury due to hot surfaces
During operation and for a short time after the inverter shuts down, the surface of the device
can reach a high temperature.
● During this time, avoid any direct contact with the surface of the inverter.
Protection and monitoring equipment
To provide protection against short-circuit, use the overcurrent devices listed in Technical data
(fuses, circuit breakers etc.).
If the apparent impedance of the line supply at the infeed point is not suitable, so that fuses
do not rupture in the specified time in the case of insulation failure (ground fault, fault to frame),
then you must use additional fault current protective devices RCD (RCCB or MRCD), type B.
In order that an RCD does not unnecessarily trip as a result of operational leakage currents,
the following preconditions must be fulfilled:
● The neutral point of the line supply is grounded.
● For inverters with rated input currents ≤ 125 A referred to LO, use an RCCB type B with a
response limit current of 300 mA. Connect the RCCB in series with the overcurrent
protective devices.
38
WARNING
CAUTION
Hardware Installation Manual, 11/2016, A5E37800827C AB
PM240P-2 Power Modules