the residual-current-operated circuit breaker is not triggered. This blocks
the triggering of a residual-current-operated circuit breaker sensitive to
power pulse current in the case of ground contact, i.e. in the case of
error.
Residual-current-operated circuit breakers sensitive to power pulse cur‐
rent do not provide any protection against inadmissible contact voltage.
2.
Residual-current-operated circuit breakers sensitive to universal current
(type B acc. to IEC 60755)
These circuit breakers are suited for smoothed direct fault currents, too,
and safely switch off devices with B6 input rectifiers.
When a current with 30 mA triggers the residual-current-operated circuit
breaker, it is possible to use a residual-current-operated circuit breaker
with higher tripping current for machine protection.
If this residual-current-operated circuit breaker triggers accidentally, too,
check in how far the above conditions and dependencies can be im‐
proved (for example, by connecting current-compensated mains chokes
in the incoming circuit, increasing the inrush current limitation).
Using Isolating Transformer to Re‐
duce Leakage Current in Mains
If there is no improvement achieved and the residual-current-operated circuit
breaker, due to specific mains conditions on site, has to be used neverthe‐
less on the mains input side, connect an isolating transformer between mains
connection and power connection of the drive system. This reduces the leak‐
age current in the ground wire of the mains that is produced during normal
operation which allows using the residual-current-operated circuit breaker.
Connect the neutral point of the secondary winding of the isolating transform‐
er to the equipment grounding conductor of the drive system.
Adjust the ground-fault loop impedance to the overcurrent protective device
so that the unit can be switched off in the case of failure.
Before operating enable, check the correct function of the overcurrent protec‐
tion device including activation in the case of failure.
Exclusive fusing by residual-current-operated circuit breaker
For drive systems with electronic drive controllers, exclusive protection by
means of a residual-current-operated circuit breaker normally is not possible
and not allowed.
Electronic equipment that has a nominal power higher than 4 kVA or is des‐
tined for permanent connection does not need residual-current-operated cir‐
cuit breakers.
According to IEC 364 and EN 50178, the supply-side protection against con‐
tact for indirect contact, i.e. in the case of insulation failure, has to be provi‐
ded in a different way, for example by means of overcurrent protective de‐
vice, protective grounding, protective-conductor system, protective separation
or total insulation.
Using Residual-Current-Operated Circuit Breakers at HCS Drive Controllers
HCS Drive Controllers at Residu‐
al-Current-Operated Circuit Break‐
er
Residual-current-operated circuit breakers can be used under the following
conditions:
●
Residual-current-operated circuit breaker is of type B (IEC60755)
●
Trip limit of the residual-current circuit breaker is ≥ 300 mA
●
Supplying TN-S mains
●
Maximum length of motor cable 20 m in shielded design
●
Use of an HNF01 or NFD03 mains filter
DOK-INDRV*-SYSTEM*****-PR06-EN-P
Rexroth IndraDrive Drive Systems with HMV01/02 HMS01/02, HMD01, HCS02/03
Bosch Rexroth AG
91/309
Project Planning of Mains Connection
