ground bar / neutral bar bonded together

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ss electric

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service call. washer trips cb [not all the time] laundry outlet on gfi cb.
moved to standard cb. noticed ground and neutral bar bonded together.
duplex looked to be 2/3 years old. inspector missed this. QUESTION?
having ground and neutral bonded,doesn't this interfere with gfi cb and
arc fault type cb working properly? resistence?
 
ss electric said:
service call. washer trips cb [not all the time] laundry outlet on gfi cb.
moved to standard cb. noticed ground and neutral bar bonded together.
duplex looked to be 2/3 years old. inspector missed this. QUESTION?
having ground and neutral bonded,doesn't this interfere with gfi cb and
arc fault type cb working properly? resistence?
Click to expand...

didn't notice meter base location
sub-panel [inside house]
 
The meter base location is not relevant. Is there a Main breaker ahead of this panel? How do you know this is a sub panel if you didn't check outside to see if there was a Main located there?


Roger
 
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The GFCI c/b should function properly regardless of wether it is installed in a main panel with the bonding jumper or in a sub panel with or without the bonding jumper installed. In the sub panel (in the same building) the neutral should be isolated but it won't change the operation of the GFCI c/b or device.

Bob on the left coast.
 
What's more, a GFCI doesn't even require an EGC to operate, only that one of the conductors be grounded.

Note: On the other hand, unlike the built-in test button, a plug-in tester does require that an EGC be present.
 
Hello Todd. I did see where you were going and I see the same thing. ;)

Roger
 
LarryFine said:
What's more, a GFCI doesn't even require an EGC to operate, only that one of the conductors be grounded.

Note: On the other hand, unlike the built-in test button, a plug-in tester does require that an EGC be present.
Click to expand...


Does a 2 pole GFCI CB feeding a 2 wire circuit require one of the conductors to be grounded? I would say no.
 
I'm of the impression a GFCI doesn't even need a grounded conductor, such as putting one on an isolated power supply where neither conductor is grounded. GFCI's are designed to trip on an imbalanced of current on the conductors beyond a set threshold. The TEST button creates such an imbalance internally.
 
infinity said:
Does a 2 pole GFCI CB feeding a 2 wire circuit require one of the conductors to be grounded? I would say no.
Click to expand...
It does require one of the source-side conductors to be grounded, as we all know.


Smart $ said:
I'm of the impression a GFCI doesn't even need a grounded conductor, such as putting one on an isolated power supply where neither conductor is grounded. GFCI's are designed to trip on an imbalanced of current on the conductors beyond a set threshold. The TEST button creates such an imbalance internally.
Click to expand...
That's true; the internal test button will trip a GFCI even when on an isolated circuit. However, an external accidental contact will have no effect, because there's no return path. There will be no imbalance if there's no current flow outside the intended circuit.

My point is that a GFCI's operation depends on the system being grounded. Otherwise, there's no current through the accidental body-to-earth contact. This is similar to the way a non-grounded Delta system will not trip a breaker upon the first fault to ground.
 
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I disagree. A gfci does not need to be grounded to function properly. If a person comes in contact with the ungrounded conductor and creates a path to ground (shock) the GFCI will sense an imbalance between the ungrounded (hot) conductor and the grounded (neutral) conductor and will open the circuit at between 4 & 6 MA.

Bob on the left coast.
 
Neutral to Ground Will Trip GFCI

Neutral to Ground Will Trip GFCI

A contact of a grounded conductor (neutral) to a ground will trip the GFCI of an active circuit (such as a hot circuit with a light turned on) because the parallel return path will carry enough current to make the current in the grounded and ungrounded couductors differ by more than that required to trip the GFCI.
 
bkludecke said:
I disagree. A gfci does not need to be grounded to function properly. If a person comes in contact with the ungrounded conductor and creates a path to ground (shock) the GFCI will sense an imbalance between the ungrounded (hot) conductor and the grounded (neutral) conductor and will open the circuit at between 4 & 6 MA.
Click to expand...

First of all, I'm talking about a grounded circuit conductor here, not an EGC.

But if there is no grounded circuit conductor, then no current will travel through a person's body. Picture the current pathways, using a panel-mounted GFCI breaker:

First, with a grounded circuit conductor: Transformer secondary to panel, breaker to black wire, through human body, into earth or other grounded surface, into grounded system neutral, back to transformer.

Now, without grounded circuit conductor: Transformer secondary to panel, breaker to black wire, into human body, then into the ozone. No current will flow because there's no secondary connection to earth.

A plug-in GFCI tester will not trip a GFCI that has no EGC for the same reason. The built-in test button has access to the neutral ahead of the torroid (current sensor), while the plug-in tester does not.
 
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Larry,
My point is that a GFCI's operation depends on the system being grounded. Otherwise, there's no current through the accidental body-to-earth contact.
Click to expand...
True, but if there is no current flow there is no hazard and no reason for the GFCI to trip. In the event that some condition such as capacitance or a partial ground would permit current flow in excess of 5mA, then the GFCI will trip even on an "ungrounded system".
Don
 
A question.....If I have a 2 pole GFI breaker feeding a 2 wire circuit (no ground or neutral) and I have a ground fault (to earth) from the equipment being fed with this circuit, will the GFI trip?
I'm not talking about overcurrent.
Assume that the GFI is properly installed in the breaker panel.
steve
 
hillbilly said:
If I have a 2 pole GFI breaker feeding a 2 wire circuit (no ground or neutral) and I have a ground fault (to earth) from the equipment being fed with this circuit, will the GFI trip?
Click to expand...
iwire said:
Yes it will trip somewhere between 4 to 6 ma.
Click to expand...
Which can only be attained if there is enough continuity between the neutral of the system and the conductive surface where the fault contact is being made.

That was my point.
 
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