TT system
TT system
Reference
1)
Information
TT system with separate
neutral conductor and pro-
tective earth in the same
system.
The N conductor is connec-
ted directly to the current
source.
Fig. 31F1
System is supported.
Connect device to the distribution network of the current
source as follows:
–
either between a mains phase and N or between 2
mains phases (230 V AC, LL)
For DC link coupling, connect only one device directly to
the distribution network of the current source. Connect
the coupled devices to the same mains phase using
cross wiring.
2)
1)
è
IEC 60364-1, chapter 312.2.
2) For cross wiring, only one master switch and one circuit breaker is allowed for the compound device.
Tab. 16 TT system
IT system
IT system
Reference
1)
Information
IT system with insulation of
active parts separated from
protective earth or connec-
ted via high impedance.
The exposed conductive
parts are connected to a
local earth.
Fig. 31G1
System is supported.
–
Connect device to the distribution network of the
current source between a mains phase and N.
A device or compound device must not be connected
between 2 mains phases.
–
The permissible system voltage of the CMMT-AS is
300 V in accordance with IEC 61800-5-1. Observe
the restrictions set out in IEC 61800-5-1 when oper-
ating the CMMT-AS in an IT network!
–
Use insulation monitoring system so that insulation
faults can be detected immediately (earth-leakage
monitor).
–
Interrupt the internal connection of the internal
mains filter to PE
è
Interrupting the connection of the internal mains
filter to PE (for IT networks only).
–
Use external filter measures that ensure CE conform-
ity.
For DC link coupling, connect only one device directly to
the distribution network of the current source. Connect
the coupled devices to the same mains phase using
cross wiring.
1)
è
IEC 60364-1, chapter 312.2.
Tab. 17 IT system
Installation
25
Festo — CMMT-AS-C2/C4-3A-... — 2018-02
