Wire gutter as a ground path

[stevej]

Question?If multiple MC's are ran to a wire gutter, the equipment grounds from the MC are terminated in the gutter and the ?hots? and ?neutrals? are ran over 20? away in the gutter to the panels, without the grounds, thus using this gutter as a ground path for the MC, is this legal? If not, why?
Thanks

 

[mcclary's electrical]

Question…If multiple MC's are ran to a wire gutter, the equipment grounds from the MC are terminated in the gutter and the “hots” and “neutrals” are ran over 20’ away in the gutter to the panels, without the grounds, thus using this gutter as a ground path for the MC, is this legal? If not, why?
Thanks

It is legal assuming gutter is properly bonded

 

[petersonra]

250.118 Types of Equipment Grounding Conductors.
The equipment grounding conductor run with or enclosing
the circuit conductors shall be one or more or a combination
of the following:
***
(13) Other listed electrically continuous metal raceways
and listed auxiliary gutters.

Note what I bolded and underlined.

However, I am not convinced the connection between the gutter and the panelboard is a legal EGC.

 

[LarryFine]

However, I am not convinced the connection between the gutter and the panelboard is a legal EGC.

Wouldn't one have to see said connection to say either way?

 

[stevej]

Note what I bolded and underlined.

However, I am not convinced the connection between the gutter and the panelboard is a legal EGC.

If the ends of the gutters are bolted together with the suppied connections, have would you know if its legal?

 

[mcclary's electrical]

If the ends of the gutters are bolted together with the suppied connections, have would you know if its legal?

Agreed.....

 

[petersonra]

If the ends of the gutters are bolted together with the suppied connections, have would you know if its legal?

One might argue it this way.

The entire egc path has to be one of the specified items in 250.118.

Panelboards are not one of the specified items.

Say you have a sheet metal junction box and come in one side with EMT. Clearly you can consider the sheet metal box as properly bonded via the EMT (assuming properly made up and all).

BUT, can you continue out the other side of the sheet metal box with another similarly made up piece of EMT and be code legal using the EMT to bond downstream boxes?

My suggestion is that unless the sheet metal box is either listed as part of an EMT system, or listed as a gutter, you are out of luck.

 

[Pierre C Belarge]

One might argue it this way.

The entire egc path has to be one of the specified items in 250.118.

Panelboards are not one of the specified items.

Say you have a sheet metal junction box and come in one side with EMT. Clearly you can consider the sheet metal box as properly bonded via the EMT (assuming properly made up and all).

BUT, can you continue out the other side of the sheet metal box with another similarly made up piece of EMT and be code legal using the EMT to bond downstream boxes?

My suggestion is that unless the sheet metal box is either listed as part of an EMT system, or listed as a gutter, you are out of luck.

Are you also then saying that all panels that have the metallic wiring methods (such as AC) or EMT, RMC, IMC are not legal because Panelboards are not specified in 250.118?
Take a peek at 408.40, I think that will help alleviate the discomfort of allowing panelboard cabinets as part of the effective ground fault current path.
If you want to take it a step further, see Article 312 and the definitions of cabinet and cutout box in Article 100

250.118(13) is the subsection to reference.

If I understand the OP, he has the MC insulated EGCs bonded to the wireway. If the wireway is listed (most likely it is), and the wireway is bolted to the enclosure as per the instructions, I see no reason not to permit this installation. The procedure explained (as I understand it) is a standard industry practice.
Last week I counted approximately 5 million linear feet of wireway bolted together across the country...I had some spare time.

An effective ground fault current path is established to carry the potential fault current.

 

[mcclary's electrical]

One might argue it this way.

The entire egc path has to be one of the specified items in 250.118.

Panelboards are not one of the specified items.

Say you have a sheet metal junction box and come in one side with EMT. Clearly you can consider the sheet metal box as properly bonded via the EMT (assuming properly made up and all).

BUT, can you continue out the other side of the sheet metal box with another similarly made up piece of EMT and be code legal using the EMT to bond downstream boxes?

My suggestion is that unless the sheet metal box is either listed as part of an EMT system, or listed as a gutter, you are out of luck.

I agree with Dennis, by your logic, we would not be allowed to add grounding blocks to service panels without jumpers.

Yes, your emt would be legal to continue out the other side of gutter and be the EGC in your example.

 

[petersonra]

I agree with Dennis, by your logic, we would not be allowed to add grounding blocks to service panels without jumpers.

Yes, your emt would be legal to continue out the other side of gutter and be the EGC in your example.

I agree this is common practice but I see nowhere in 408.40 that contradicts the edicts of 250.118.

Adding grounding bars without running a jumper to the existing bar is something common that also appears to be outside the edicts of 250.118.

I am not saying it is a bad idea, just that the actual text of the code says something very specific and common practice is something else.

 

[mcclary's electrical]

I agree this is common practice but I see nowhere in 408.40 that contradicts the edicts of 250.118.

Adding grounding bars without running a jumper to the existing bar is something common that also appears to be outside the edicts of 250.118.

I am not saying it is a bad idea, just that the actual text of the code says something very specific and common practice is something else.

The very fact that EMT can be used as an EGC, without installing a bonding bushing, tells me that it is permitted by the NEC, even if not included in your list.

2ndly, It would be impossible to comply with 250.24 (b) (as worded)without using the panel as a path

 

[petersonra]

The very fact that EMT can be used as an EGC, without installing a bonding bushing, tells me that it is permitted by the NEC, even if not included in your list.

I looked at article 358. Perhaps I missed the part where any of the requirements of 250.118 are waived.

2ndly, It would be impossible to comply with 250.24 (b) (as worded)without using the panel as a path

The MBJ is not an EGC. However, the code does fairly clearly allow the neutral bar to be used as a place to terminate EGCs.

 

[mcclary's electrical]

I looked at article 358. Perhaps I missed the part where any of the requirements of 250.118 are waived.



The MBJ is not an EGC.

Yes, but as worded, it says the MBJ connects the EGC's, and panel, to the grounded conductor. How do you propose doing that without using the panel as a path? THE EGC's are landed on the panel, the panel gets connected to the grounded conductor via the MBJ, so, complying would be impossible per your logic.

Secondly 250.118 (14) pretty much squashes your argument,

if not 250.118 (13),,,,I'll call a panel board "busway framework",,,,since the panel has a buss and installed in framework:grin:

 

[Pierre C Belarge]

I agree this is common practice but I see nowhere in 408.40 that contradicts the edicts of 250.118.

Adding grounding bars without running a jumper to the existing bar is something common that also appears to be outside the edicts of 250.118.

I am not saying it is a bad idea, just that the actual text of the code says something very specific and common practice is something else.

408.40 supplements/augments/compliments/is in addition to 250.118. No one mentioned that it contradicts 250.118

250.118 is only a portion of the Effective Ground-Fault Current Path. Do not think of it as the beginning and the end of....

You should try to take a different approach in how you are thinking, and reading the NEC.

250.4(A)(5) Effective Ground-Fault Current Path
Electrical equipment and wiring and other electrically conductive material likely to become energized...


1. This is our starting point, the most important aspect of electrical wiring.

*The rest of the path does not have to follow any order.

2. 408.40/312/Art 100 all combine to help us put the puzzle together.

3. 250.118 With other portions of the NEC (I am too lazy to put it together...it would be a book and take way too long) complete the EGFCP in a safe and professional manner.