AMTRAK Car Electrical System

[dkidd]

I don't see anything about 120 or 208 on the links, or GFCI. Do you have a specific link on those sites?

 

[ronaldrc]

I took it into the restroom where there is a GFCI receptacle, and it didn?t have a ground either. Pressing the test button did not trip anything, since there was no connection to the ground prong.
Any thoughts?

Did you try the built in test button on the GFI receptacle in the restroom? If it did not trip with it, the recpt.
was bad you wouldn't need a system ground of any kind for that test button to work.

 

[dkidd]

Yes, the test button worked. But then I remember a few years ago that if the receptacle was misconnected with the line on the load side that the test button would trip it, but it did not (obviously) provide protection for anything plugged in.

 

[ronaldrc]

Yes, the test button worked. But then I remember a few years ago that if the receptacle was misconnected with the line on the load side that the test button would trip it, but it did not (obviously) provide protection for anything plugged in.

Then I think it is just a non grounded system and the designer knew the GFIs would become fucntional
as soon as either line 1 or line 2 of the transformer contacted the Amkrak chassic or metal frame.

I"ve not tried this on the bench but I believe it will make the GFI recpt. functional if ether line 1 or line 2 get grounded.

 

[LarryFine]

Then I think it is just a non grounded system and the designer knew the GFIs would become fucntional
as soon as either line 1 or line 2 of the transformer contacted the Amkrak chassic or metal frame.

And, until then, there is no line-to-chassis hazard.

I"ve not tried this on the bench but I believe it will make the GFI recpt. functional if ether line 1 or line 2 get grounded.

I believe that to be correct. The GFCI does not care which conductor is grounded, only that one is.

 

[ronaldrc]

Larry I will try that in a day or two and let you know the results.

 

[ronaldrc]

Here are the results of the bench test on the grounding of the GFI receptacle.
From either the hot or neutral side of the GFI recpt.

Note I did not take any amperage or current measurements on the tripping current.
So do not try too apply this to a circuit untill it has been proven to be safe by a Certified
Electrical Engineer. Thanks

 

[dkidd]

a Certified
Electrical Engineer

iwire thinks all engineers should be certified.:grin:

 

[ronaldrc]

I have been introduced to many Very knowledgible folks with the title of Engineer
that did not have the papers.

You find a lot of them at utility companies.

 

[kwired]

A GFCI does not care which or if either conductor is grounded. All it cares about is that all current that leaves one conductor returns on another - even with MWBC GFCI's. If you have a non grounded system the chance of having current not return on the other circuit conductor(s) is greatly diminished, until a conductor becomes grounded.