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In a cross-bonded system, the increasing voltage gradient from the earthed point to the bonding point is caused by the induced voltage from the AC current flowing in the cable conductors. While the earthed points hold the sheath at ground potential, the magnetic field induces voltages in the...

why current transformers (CTs) shouldn’t be grounded on both sides: 1. Avoiding Ground Loops: What is a ground loop? A ground loop occurs when both ends of the CT secondary circuit (the measuring circuit) are grounded, creating a closed loop through the ground. In such a loop, unwanted currents...

1. Grounding Grid Purpose: The primary function of a grounding grid is to protect people and non-current carrying metallic objects, such as poles, towers, equipment enclosures, and switch handles, by keeping the ground potential as close to zero as possible during fault conditions. 2. Fault...

Stevenal, Do you think we could still experience a neutral shift even with an earthing transformer in place? Beyond8, Do we need to consider changing the earthing transformers?

plase see attahecd disturbance recoder of the incomer.https://files.engineering.com/getfile.aspx?folder=094eb683-c019-4461-adeb-5613182e251e&file=REF630-AA1MVA01A1_DR111_20240801151724_240922_130224.pdf

the fault was 10km away plase see attahecd disturbance recoder of the feeder.https://files.engineering.com/getfile.aspx?folder=61cd71a9-8fc9-48d2-a2b7-3f14a07a515e&file=REF630-AA1MVA03A1_DR114_20240801141654_240922_130137.pdf

The fault happend on outggoing feeder h03 or h04 See the attached sld on my previous reply

Yup we use our earthing transformer ZNyn1 to feed out 0.4kv system Please see attached SLDhttps://files.engineering.com/getfile.aspx?folder=de666175-3cd2-479b-891e-782a52c1ccdd&file=2GJA321107_RevA_240922_195536.pdf

Dears We are experiencing an issue where, during an earth fault on our 33 kV outgoing feeder, the voltage measured by the ABB REF relay (Vo) on the incomer spikes to around 14 kV. This overvoltage is affecting our 0.4 kV system, which is fed by our ZNyn1 earthing transformer. Is this behavior...

Thanks all Why we need to ground open delta PT at one corner?

Waaross Is there any chance that charging current will be reflected in the star ground side

Hi all I have YNd11 transformer used as stepdown from 33kv(YN) to 11kv(d) to feed loads in 11 kv side -The question is If we have earth fault in 11kv systems how we can detect it. -is there will be reflection on star side of this earth fault. -Is it possible to have earth fault in this case...

Thanks all

So we don't need any synch check in case of identical power transformer closing because there is no phase shift in the secondary

So we just close the tie beacker without any synch.

Hi all We have 2 identical step down 33/11kv power transformers fed from single source and feed radial lods with no generation at 11kv side. Does we need to have synchronisation between them in 11kv side Thanks in advance

thanks MikeL your feedback was very valuable.

yup sir there 24VDC With the CGCM powered down. I wonder if it possible to open CGCM and try to rectify it from inside.

catserveng thanks for your feedback i checked the fault relay configuration tap in CGCM module throw RSlogix5k there is just tow function that are activated (PT sensing loos and Over_excitation) I uncheck these two function then apply and send the change to CGCM but FLTrelay still active. I...

Drivesrock Actually this AB 1407-CGCM connected to Rockwell RSLogix5K. I trace every fault bit in PLC software but I couldn't find any fault. the fault came form CGCM FLT relay but in PLC all FLTrelay output is OK. So, it maybe internal hardware issue.