Ground fault protection system is provided for the protection from line to line ground faults that occur on the ___ of the service disconnect means:

[ramihamdan]

Hi all, So this question was on Electrical contractor exam in Indiana.
The options were

Both Line side and Supply side
Supply Side
Line side

The answer was the Line side. However I found (2008 NEC) code reference 230.82(8) and 230.95 FPN no .1. stating both sides need ground fault protection. I'm also confused by this question because i thought line side and supply side mean the same thing.

 

[don_resqcapt19]

The note in 230.95 only suggests that downstream ground fault protection may be needed if you want the system selectively coordinated. There are only a few cases where selective coordination is required by the code, but it may be required by the design documents.

The 2008 code also requires ground fault protection for feeders in 215.10. In the 2014 code, 210.13 was added to require ground-fault protection for large branch circuits.

 

[texie]

"line to line ground faults" is an oxymoron. GFPE systems only directly protect against line to ground faults.​

Sure, a line to line fault may propagate into a line to ground fault but they do not see line to line faults.

 

[electrofelon]

Hi all, So this question was on Electrical contractor exam in Indiana.
The options were

Both Line side and Supply side
Supply Side
Line side

The answer was the Line side. However I found (2008 NEC) code reference 230.82(8) and 230.95 FPN no .1. stating both sides need ground fault protection. I'm also confused by this question because i thought line side and supply side mean the same thing.

Are you sure you are remembering the question and answer correctly? Multiple problems with the question. First there is the problem Texie mentioned. Then, as you questioned, line side and supply side are the same thing. The answer should be load side. GFPE will not protect upstream conductors.

 

[jaggedben]

Are you sure you are remembering the question and answer correctly? Multiple problems with the question. First there is the problem Texie mentioned. Then, as you questioned, line side and supply side are the same thing. The answer should be load side. GFPE will not protect upstream conductors.

Yeah, litterally everything is wrong.

 

[electrofelon]

Here is what an informational note to 230.95 says in the 2017 NEC:

Informational Note No. 1: Ground-fault protection that functions to open the service disconnect affords no protection from faults on the line side of the protective element. It serves only to limit damage to conductors and equipment on the load side in the event of an arcing ground fault on the load side of the protective element