Article 517 Health Care Facilities

[vewright]

Some research has convinced me that Article 517.13 Grounding of Receptacles and Fixed Electric Equipment in Patient Care Areas is intended to require redundant grounding systems in patient care areas--one consisting of a metallic raceway system, and the other consisting of insulated copper conductors. However, nowhere in this section does the word "redundant" appear. Nor does paragraph B stipulate the extent of the insulated copper conductors.

Question: If the authors of the Code want redundant grounding, why doesn't the article read something like,

Patient care areas shall be provided with redundant grounding systems consisting of a metal raceway system installed in accordance with 250.118 and a system of insulated copper grounding conductors extending from all receptacles and fixed equipment to a common grounding point in the grounding electrode system.

As written, the article could be interpreted to mean that the insulated copper conductors could be terminated at the outlet box that is part of the raceway system. In fact, the Handbook asserts that it is not necessary to run a separate, insulated equipment grounding conductor to the branch circuit panelboard wehre the feeder wiring method is recognized as an equipment grounding conductor per 250.118.

 

[roger]

The code wants two EGC's in parallel and we can refer to it as redundant (which is the function of the insulated conductor) but the NEC does not, I don't see a problem with it.

The NEC doesn't use the term "Sub-Panel" either but generally speaking, we in the trade do and know what we are talking about when using trade slang.

I believe Mark Ode used the term redundant ground in a article he wrote for EC&M about patient room grounding and I think Gaylen Rogers used the term in an article as well.

You could submit a proposal.

Roger

 

[kwired]

The 'redundant' grounding is required for branch circuits supplying most equipment in patient care areas.

It is not required for services or the feeder supplying the panel.

 

[vewright]

Article 517 Health Care Facilities

The 'redundant' grounding is required for branch circuits supplying most equipment in patient care areas.

It is not required for services or the feeder supplying the panel.

So, does the EGC required by 517.13 (B) have to go back to the panel that supplies the branch circuit, or can it be connected to the outlet box with a grounding screw or a listed clip?

 

[augie47]

It does go far as to say " The equipment grounding conductor shall be sized in accordance with Table 250.122 and installed in metal raceways or as a part of listed cables having a metallic armor or sheath assembly with the branch-circuit conductors supplying these receptacles or fixed equipment."
dictating that it must be part of the branch circuit wiring.
The only thing it doesn't specifically tell you is to terminate it at the branch circuit panelboard.

 

[roger]

So, does the EGC required by 517.13 (B) have to go back to the panel that supplies the branch circuit, or can it be connected to the outlet box with a grounding screw or a listed clip?

It would have to do both to be considered an EGC on it's own.

Roger