Pieterxstrata
Electrical
- Jul 19, 2011
- 3
Is there somebody that can help me with a operating prosedure to do 3 phase earth leakage tests on a 525v system.
Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
3 Phase Earth Leakage Test
- Thread starter Pieterxstrata
- Start date
- Status
rcw retired EE
Electrical
What is the objective?
Determine the average quality of the system's insulation? or
Measure the actual capacitive leakage current for sizing neutral groudnign resistors?
An insulation resistance measurement could be done on a de-energized system by jumpering three phases together, removing any connection to earth and apply 1,000 VDC with an insulation resistance test instrument. (Commonly called a Meggar in North America). The result will be the combined insulation resistance to ground of the system that was connected at the time of the test. It would not provide much useful information about the condition of the individual equipment items: wires, transformers, panels, etc.
I don't recommend trying these test unless you really understand the risks. Besides the obvious risk of working on electrical equipment, some devices connected to your system might get ruined by a DC overpotential test.
Capacitive charging current measurements can be done several ways on energized systems. Let us know what you are trying to do.
Determine the average quality of the system's insulation? or
Measure the actual capacitive leakage current for sizing neutral groudnign resistors?
An insulation resistance measurement could be done on a de-energized system by jumpering three phases together, removing any connection to earth and apply 1,000 VDC with an insulation resistance test instrument. (Commonly called a Meggar in North America). The result will be the combined insulation resistance to ground of the system that was connected at the time of the test. It would not provide much useful information about the condition of the individual equipment items: wires, transformers, panels, etc.
I don't recommend trying these test unless you really understand the risks. Besides the obvious risk of working on electrical equipment, some devices connected to your system might get ruined by a DC overpotential test.
Capacitive charging current measurements can be done several ways on energized systems. Let us know what you are trying to do.
- Thread starter
- #3
Pieterxstrata
Electrical
- Jul 19, 2011
- 3
Hi there,
Sorry for the late replay, It came under my attention that the electricians do not know how to do the earth leakage test.
I need to draw up a one page prosedure on how to test and proof the operation off the earth leakage.
Yes I agree with you that to do a Megger test on the cable and motor as is de-energised and safe.
Will let you know on what we desided in South Africa.
Thanks
Pieter
Sorry for the late replay, It came under my attention that the electricians do not know how to do the earth leakage test.
I need to draw up a one page prosedure on how to test and proof the operation off the earth leakage.
Yes I agree with you that to do a Megger test on the cable and motor as is de-energised and safe.
Will let you know on what we desided in South Africa.
Thanks
Pieter
- Status
Similar threads
- Question
- Locked
- Question
- Question
- Locked
- Question