An operate and start signal from the low stage is used to provide a LED indication
on the LHMI. Separate start and operate signals from both functions are connected
to the disturbance recorder.
3.2.6.9 Non-directional earth-fault protection EFxPTOC
The non-directional earth-fault protection functions are used for protection under
earth-fault conditions with definite-time (DT) or with inverse definite minimum
time (IDMT) characteristic when appropriate.
The operation of the stage can be based on three measuring principles: DFT, RMS
or peak-to-peak values. The configuration includes high stage and low stage non-
directional current function blocks. The set of three phase currents, I3P, is
connected to the inputs. During the startup, for avoiding unnecessary operations,
the start value of both instances is multiplied by a setting parameter Start value
Mult. Both instances of the earth fault protection are blocked by the start of the
instantaneous overcurrent protection.
A common operate and start signal from high stage and low stage earth-fault
protection functions are connected to an OR-gate to form a combined non-
directional earth-fault operate and start signal which is used to provide a LED
indication on the LHMI. Separate start and operate signals from both of these
functions are connected to the disturbance recorder.
3.2.6.10 Positive-sequence overvoltage protection PSPTOV
The positive-sequence overvoltage function blocks are used for positive-sequence
overvoltage protection with definite-time characteristic. The set of three phase
voltages, U3P, is connected to the inputs.
The operate and start signals from the positive-sequence overvoltage function is
used to trigger the disturbance recorder.
3.2.6.11 Positive-sequence undervoltage protection PSPTUV
The positive-sequence undervoltage function blocks are used for positive-sequence
undervoltage protection with definite-time characteristic. The set of three phase
voltages, U3P, is connected to the inputs.
The operate and start signals from the positive-sequence overvoltage function is
used to trigger the disturbance recorder. The undervoltage function is blocked by
the fuse failure function and during starting condition of the motor.
3.2.6.12 Negative-sequence overvoltage protection NSPTOV
The negative sequence overvoltage function blocks are used for negative-sequence
overvoltage protection with definite-time characteristic. The set of three phase
voltages, U3P, is connected to the inputs.
Section 3 1MRS756785 A
REM630 variants
34 REM630
Application Manual
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