Grounding isolated ground recepicles

[J-R]

Could someone confirm for me when using HCF MCAP it is allowed not to bond green equip ground conductor to box for isolated ground recepicles as 250.146d Thanks for the help

 

[Buck Parrish]

It's the UL Listing see here
http://www.southwire.com/products/HCFMCAPTypeMCAllPurposeHospitalCareFacility.htm

 

[J-R]

Thanks for the help

 

[Buck Parrish]

Your welcome

 

[erickench]

I believe the equipment ground for an isolated grounding receptacle can pass through boxes and enclosures unbonded all the way back to the panel where the circuit originated.

 

[LarryFine]

I believe the equipment ground for an isolated grounding receptacle can pass through boxes and enclosures unbonded all the way back to the panel where the circuit originated.

Correct. You basically treat it like a circuit conductor until it reaches the MBJ point.

 

[Microwatt]

Correct. You basically treat it like a circuit conductor until it reaches the MBJ point.

What if the MBJ is in a different building? Would bringing it back to the SBJ still qualify it as an isolated ground?

 

[LarryFine]

What if the MBJ is in a different building?

Then you bond it where this buildings electrodes land.

 

[HighVoltage4160]

Do I have to ground to the metal box and the panel ground

Do I have to ground to the metal box and the panel ground

If I am installing an isolated ground circuit do I have to ground first to the metal box of the receptacle and then straight back to the panel or from the receptacle straight back to the panel without grounding to the box?

 

[Dan coulstring]

If I am installing an isolated ground circuit do I have to ground first to the metal box of the receptacle and then straight back to the panel or from the receptacle straight back to the panel without grounding to the box?

FPN 250.146(D) Correct me if I am wrong but you need a seperate EGC for the box and raceway seperate from the isolated EGC

 

[infinity]

FPN 250.146(D) Correct me if I am wrong but you need a seperate EGC for the box and raceway seperate from the isolated EGC

That is true. It can be the listed EGC as the jacket of a metallic raceway or a metal conduit but it is required.

 

[jamesoftn]

Go to www.ecmweb.com/mag/electric_basics_isolated_grounding/index.html

Not so sure I agree with all of this information but would like to get some responses back on this subject. Basically I feel if the isolated ground receptacle conductor is not ran back to the main panel/system ground you are wasting your time and dollars installing this equipment. Just use regular receptacles.

 

[infinity]

Go to www.ecmweb.com/mag/electric_basics_isolated_grounding/index.html

Not so sure I agree with all of this information but would like to get some responses back on this subject. Basically I feel if the isolated ground receptacle conductor is not ran back to the main panel/system ground you are wasting your time and dollars installing this equipment. Just use regular receptacles.

Which information are you disagreeing with?

I agree that the IG to be of any use must be run back to the point where the neutral and ground are bonded together.

 

[flashlight]

Which information are you disagreeing with?

I agree that the IG to be of any use must be run back to the point where the neutral and ground are bonded together.

We did a floor in a commercial bldg. that was powered from 2 200A subpanels.

In certain areas, Isolated Ground receptacles were spec'd, and those had a separate ground conductor that landed at the equipment ground bus at a subpanel.

The alternative would have been an additional run of approx. 200 ft, mostly straight down, to bsmt. and SBJ location.

The engineer signed off on our installation, but as we know some engineers will sign off on a ham sandwich--(not the ones in the forum, of course )

Is the setup as described "of any use" ?

 

[infinity]

We did a floor in a commercial bldg. that was powered from 2 200A subpanels.

In certain areas, Isolated Ground receptacles were spec'd, and those had a separate ground conductor that landed at the equipment ground bus at a subpanel.

The alternative would have been an additional run of approx. 200 ft, mostly straight down, to bsmt. and SBJ location.

The engineer signed off on our installation, but as we know some engineers will sign off on a ham sandwich--(not the ones in the forum, of course )

Is the setup as described "of any use" ?

IMO in a commercial building as you've described the IG system is a complete waste of someone's money. And judging from the way that your system was setup I wouldn't even call it an IG system. I'm a little baffled as to why someone would want an IG system in the first place and secondly why they would allow the IG EGC's to simply terminate in a branch circuit panel. :-?

 

[flashlight]

The way it was installed is actually how it was spec'd by ee. Nobody wanted to spend the money to core drill to bsmt. but it was felt that landing the IG 80 feet away protected some electronics better than not having IG.