AC or MC cable for a health care

[steve66]

Code Q & A in a recent EC&M magazine says that AC cable can be used in patient care areas because it has a bonding strip that makes it a suitable fault current path. It also says that MC cable isn't suitable as a fault current path and can't be used in patient care areas.

Is it really this simple? All AC is OK, and all MC is not? Or are there non-hospital grade AC cables or hospital grade MC cables?

Steve

 

[caj1962]

Re: AC or MC cable for a health care

Steve
what you are refering to is an AC cable. What I have been using is mabe by alflex and is AC cable with stranded THHN conductors. The outer sheath of the cable is green (for the inspector) It also has a listing on it for Health care applications. It also has on the packaging a note that ot cannot be used with set screw contectors. There is also a plastic tracer inside that says the same thing. I always take the grounding conductor to back of the box or wrap it back on the sheath.

 

[don_resqcapt19]

Re: AC or MC cable for a health care

Steve,
Not all AC cable is suitable for patient care area branch circuits. Only AC cable that has an internal EGC is suitable for that application. Most MC cable is not suitable as the metallic sheath of MC cable with the interlocking armor type of jacket is not suitable for use as an EGC. MC cable with the outer metallic jacket of the smooth or corrugated tube type that has an internal EGC would be suitable, but these types of MC are somewhat rare and hard to work with do to the stiffness.
Don

 

[ed downey]

Re: AC or MC cable for a health care

Steve, I Know You Didn't Ask This Question But Make Sure That You Note That AC Cable Cannot Be Used For Emergency Circuits {517-30(c-3)}. You Would Be Surprised How Many Electricians I Run In To At Hospitals That Do Not Know This.
-Ed

 

[roger]

Re: AC or MC cable for a health care

Ed, if your reference to 517-30(c)(3) would be from the 99 NEC (note the dash) HCFC was allowed for "Emergency Branch Circuits" so those who are still operating under the 99 NEC can use it.

This allowance was removed in 02.

Roger

[ June 18, 2004, 04:41 PM: Message edited by: roger ]

 

[steve66]

Re: AC or MC cable for a health care

Thanks for the replies. It doesn't sound like just specifying "AC cable" is enough. It sounds like one should specify an "AC cable with an EGC and an outter jacket that complies with NEC 250.118."

Posted by Ed:

AC Cable Cannot Be Used For Emergency Circuits

Do you think light fixtures require a "flexible connection"? In other words, can the electricians use AC cable for critical branch light fixtures per 517.30(C)(3) Exception #5?

Steve

 

[ed downey]

Re: AC or MC cable for a health care

Steve,
I Believe You can Use Flexible Whips For Lighting Connections Even On The Critical Branch.
Roger,
I Have Had AHJ Even Under The 1999 Version State That The last Sentence In 517-30(c3) Does Not Change The First Sentence Where It Specifically States To Install In A nonflexible Metal Raceway.
-Ed

 

[roger]

Re: AC or MC cable for a health care

Ed, does this AHJ ignore or omit the last sentence of every article section?

Roger

 

[steve66]

Re: AC or MC cable for a health care

Roger, I think I would have to agree with the AHJ. Nothing in that last sentance says you can ignore the first sentance. The last sentance in the '99 looks like it is redundant - it just says to follow a rule that would apply anyway.

I wonder if thats why it was eliminated in 2002. It looks like they didn't really change a rule, they just eliminated some unnecessary words.

Steve

 

[roger]

Re: AC or MC cable for a health care

Actualy I think it was a mistake, but in reality by the wording, the last sentence did allow "Emergency Branch Circuits" to be installed per 517.13 no matter how we might want to interpret it.

For all we could have known, it might have been addressing only feeders for the "non flexible" method.

Roger

 

[steve66]

Re: AC or MC cable for a health care

I see your point. I think it could be interperted either way. The two sentances are almost conflicting. I think that gives the AHJ the right to decide which is required, and that would normally be the strictest rule.

I guess my point is that I don't think the AHJ was ignoring the last sentance. But I did get a laugh out of your question about ignoring every last sentance

Steve

 

[ed downey]

Re: AC or MC cable for a health care

Roger,

I Can See Your Point But I Can Also See His Point Since It Specifically States That You Need To Use A Non-Flexible Metal Conduit In The First Sentence. The Second Sentence Was Added In That One Code Cycle And Most Likely Will Not Be Heard From Again (Or At Least Until The Conduit Lobbyists Give Up That Portion).
-Ed

 

[roger]

Re: AC or MC cable for a health care

Ed, in the 2005 NEC draft it was mentioned again in 517.30(C)(3) for fishing in existing walls, I don't know where this stands at the moment.

Roger