Guys I've done very little commercial or open wall work. My question is I'm wiring a work shop (40 x 40), open beams and purlins. Sould I use BX as my trunk line then enter a junction box then use EMT to drop down to the recepticals and light switches.

Also since I will be useing single stranded wire (black, white, & green) should I run my ground (green) conductor all the way back to the service panel or is it acceptable to bond the ground in the metal boxes useing the EMT as a path for the ground as long as I use a bonding ring that the panel.

I run bx to emt all the time is the bx going to be hidden in a ceiling?I would run a ground in the emt because both compression and screw type connectors are crap.Then again i usually skin the bx to length and use a BX to EMT connector to transition to the pipe without a box and you have bare ground right there at the devise.

Frank what kind of 'BX' has a bare 'ground'?

Frank

I really hope you're NOT mistaking the aluminium bonding wire (that's supposed to be bent over the red devil and wrapped around the jacket) to be the same as the bare ground wire in NM cable!!!

Bert,
You should be fine doing the job as you stated, as long as it's all installed properly, and there aren't any local ordinances prohibiting it.
Either Type MC or AC cable will work well.
EMT is approved for grounding by the NEC, and bonding jumpers should be installed to the devices from the boxes that they are in.

Frank, I'm curious
Why do you think all EMT connectors are crap?
What is a BX to EMT Connector?

These emt-bx connectors come in handy. BX or AC90 does have a bare bond wire inside. http://www.foxelectricsupply.com/co...asp?qsCatID= 24991&qsProductNo=8610

[This message has been edited by RobbieD (edited 12-02-2004).]

[This message has been edited by RobbieD (edited 12-02-2004).]

The bare strip in AC is not a grounding conductor.

You can wrap it back or cut it off flush with the armor.

Was there a problem with these 1/2 pipe to 3/8 flex connectors having the UL listing removed? If so why? I know a number of inspectors that won't accept these. I could not find them in a Regal catolog.

Here is the Arlington Industries page: http://www.aifittings.com/b_9.htm#860

Next to all the 1/2-3/8 ones it says * CSA only.

Tom

[This message has been edited by Active 1 (edited 12-02-2004).]

OK guy's maybe were talking about different cable.I thought he was referring to AC90.When we order bx 12/2 from the wholesalers around here we actually get AC90.I have to specify BX skin and diameter if I just want the aluminum cladding.The only time we use bx skin is for fire alarm or communication circuits and it never has the bonding strap in fact i thought they didn't make it like that anymore.Same goes for the connector.EMT is almost always run with a ground around here because a lot of the time the connectors come loose and compromise the ground from vibration improper installation or rough usage.While inspection will pass some EMT installations without a ground wire they generally let you know they don't like it.I would run AC90 to EMT with a connector or go all pipe before i bothered with pulling wire in bx skin.Sorry for the slang terminology but bx and AC90 is the same here my mistake.
RobbieD,
Thats the connector i was talking about.

Iwire,I have never seen the bonding strip come in AC90 just the bare ground wire.

[This message has been edited by frank (edited 12-02-2004).]

RobbieD
I think i now see the misunderstanding.We are in Canada different rules i guess.Ho well just trying to help.



[This message has been edited by frank (edited 12-02-2004).]

The proper term for this is flexible metal conduit, or "flex" or "greenfield."


Frank, that's not the "ground wire" it's the bonding strip. If it doesn't have the bonding strip, it is not AC cable.

Peter

Yeah, well that could explain the problem here.

I did double check AFC's web site and the American AFC 90 product contains only a bonding strip, no ground wire.

No need to be sorry you where trying to help and you did.

I have now learned Canada has different cables then the USA.

We have type AC as described above and we have type MC which is also armored but has a full size insulated ground.

Either one comes in steel or aluminum armor.

Bob

Iwire and CTwireman,
I just checked our 12/2 AC90 has a #14 bare copper grounding wire but no aluminum bonding strip here in Canada.I'll have to remember our material is slightly different the next time i chime in on a question.Thanks again

[This message has been edited by frank (edited 12-03-2004).]

AC Cable is available as AC-HCF, and has an insulated ground wire.(slang term is "hospital cable")

Here's a comparison of various cables.

http://afcweb.com/pdfs/01catalog/01cat-p34-compar.pdf

Years ago #12 "BX" did come with a reduced #16 bare Cu ground wire, but I never saw any that wasn't at least as old as I was.


An inspector shouldn't approve any installation that is going to come apart from vibration, improper installation, or hard usage, ground wire or not.

Down here the inspector isn't supposed to be able to approve or disapprove an installation on what they like(although many still try).
That's what the Code is for. To give them a set of rules to follow, as well as us.



[This message has been edited by electure (edited 12-03-2004).]

If I had a choice and the customer didn't care I'd vote for as much pipe as possible. Minimum 3/4". Reason: expandability. But then again ... some jobs won't pay for the extra time it takes.

A few years back at 15 hour code review, the instructor had this old BX (don't remember the real name),well inside was only 1 insulated conductor and the metal jacket of the cable was used for the neutral.He said that the neutral of the hangin light would just connect to the box.

Any one have any storys about that stuff?

shortcircuit