Micom P139 No Disturbance record detected

[Muhammad_Hassan]

The relay does not show any disturbance record when connected through Serial Communication.
The relay performed the tripping action due to an actual fault, but still no disturbance record detected.

Moreover, the relay does not record the value of IN> on primary and secondary in FT_RC.

The relay also does not show any GF_RC on actuation of IN>.

[Rudolf_Simon]

Hello Muhammad,

Disturbance recording trigger conditions have to be set at “FT_RC: Fct. Assig. trigger” [MPA 060 000] in menu “Parameters/ Function parameters/ Global/ FT_RC”. By default, no trigger is assigned.

Your 2^nd question is not clear to me: “the relay does not record the value of IN> on primary and secondary in FT_RC.”

IN> is a threshold setting in neutral OC protection element(s); and settings are not recorded along a disturbance.

Measured values from last fault are available in menu “Events/ Measured fault data/ FT_DA”. There are measured and calculated neutral current values in per unit and primary Ampere [MPAs 004.049, 024.217, 010.216, 024.218].

Note, that these values are only evaluated, if a phase-ground loop is selected, hence for A-G or B-G or C-G faults. For phase-phase or 3-phase faults, no neutral current is evaluated.

GF_RC is a specific solution to log just events from GFDSS and TGFD in a file. These at are dedicated functions to detect ground faults in systems with isolated or compensated starpoint; usually for direction indication only, not for tripping (a ground fault in such systems is no short-circuit, just a displacement of neutral point).

GF_RC is independent from FT_RC, and contains no recording of sampled signals.

In case of neutral OC IN> operation, the disturbance recording (FT_RC) and fault data acquisition (FT_DA) should be used.

Best regards

Rudolf

[Muhammad_Hassan]

In the last fault data in menu “Events/ Measured fault data/ FT_DA", the neutral current shows "Not Measured" in per unit as well as primary.

Although the relay performed tripping action due to an earth fault.

[Rudolf_Simon · Accepted solution]

Hello Hassan,

I assume the fault duration was too short to allow fault locator operation.

If possible, you may share the recording and setting files with L3 (Boguslaw.Wilczynski@se.com) or myself (Rudolf.Simon@se.com) for more detailed review.

Best regards

Rudolf