Technical data

Siemens SIP · 2008
12 Motor Protection / 7SK80
12
12/22
Typical applications
Overview of connection types
Type of network Function Current connection Voltage connection
(Low-resistance) grounded network Time-overcurrent protection
phase/ground non-directional
Residual circuit, with 3 phase-current
transformers required, phase-balance
neutral current transformer possible
–
(Low-resistance) grounded networks Sensitive ground-fault protection Phase-balance neutral current
transformers required
–
Isolated or compensated networks Time-overcurrent protection
phases non-directional
Residual circuit, with 3 or 2 phase
current transformers possible
–
(Low-resistance) grounded networks Time-overcurrent protection
phases directional
Residual circuit, with 3 phase-current
transformers possible
Phase-to-ground connection or
phase-to-phase connection
Isolated or compensated networks Time-overcurrent protection
phases directional
Residual circuit, with 3 or 2 phase-
current transformers possible
Phase-to-ground connection or
phase-to-phase connection
(Low-resistance) grounded networks Time-overcurrent protection
ground directional
Residual circuit, with 3 phase-current
transformers required, phase-balance
neutral current transformers possible
Phase-to-ground connection
required
Isolated networks Sensitive ground-fault
protection
Residual circuit, if ground current
>0.05I
N
on secondary side, other-
wise phase-balance neutral current
transformers required
3 times phase-to-ground connection
or phase-to-ground connection with
broken delta winding
Compensated networks Sensitive ground-fault protection
cos ϕ measurement
Phase-balance neutral current
transformers required
3 times phase-to-ground connection
or phase-to-ground connection with
broken delta winding