Trumpf BendMaster 150, Operator'S Manual

Page: 60 / 258

If a residual current circuit breaker is used to provide protection
from direct contact, an
unregulated isolating transformer must
be used (EN 50178 section 5.2.11.1, VDE 0160). This is
because the fault current resulting from the design is >30 mA.
If a residual current circuit breaker is to be used to provide pro-
tection from indirect contact, this must be selected depending on
the machine's fault current.
Note
In rare cases, customer-side voltage fluctuations on the
machine's power input filter may lead to higher fault currents
than the typical value specified. The main electricity supply and
the machine must then be separated by an
unregulated isolat-
ing transformer.
If a residual current circuit breaker is used, observe the following
requirements:
BendMaster (60) BendMaster (150) BendMaster with handling equip-
ment
Type S Type S Type S
Selective Selective Selective
Sensitive to all types of c
resistant to current surges
5 kA Sensitive to all types of c
resistant to current surges
5 kA Sensitive to all types of c
resistant to current surges
5 kA
Tripping current of 300 mA Tripping current of 300 mA Tripping current of 300 mA
Values for residual current circuit breaker Tab. 2-14
Line structures
Power supply with grounded outer conductor (corner-
grounded delta network)
When connecting the machine to a power supply with a
grounded outer conductor, an
unregulated isolating transformer
must be used.
Power supply configuration:
■ A power supply in star connection and with a grounded star
point (solidly grounded wye) is required.
■ If the existing power supply is in delta connection (corner
grounded delta), the customer must install a grounded
unregulated isolating transformer in star connection (with
grounded star point) (see NEC item 450-5).
2
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16
Electrics - Version 10
B579EN
Residual current circuit
breaker for direct contact
Residual current circuit
breaker for indirect contact
NEC conditions