MC Cable Connectors

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dpenbert

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Location
Missouri
I'm designing a prefabrication system for a high rise condominium complex. In tenant units we are using MC Cable, which I am intending on having prefabricated with arlington connectors attached. My design incorporates a color code system that requires something on the prefabricated product to be color spray painted. Do I run into any code/grounding issues if I spray paint the arlington connectors at each end of the MC cable?

Thanks

--------------
David
 
iwire

iwire

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Location
Massachusetts
Re: MC Cable Connectors

David MC cable does not rely on the armor for grounding.

That aside I agree with mdshunk and would add UL to that.
 
rbalex

rbalex

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Mission Viejo, CA
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Professional Electrical Engineer
Re: MC Cable Connectors

Originally posted by iwire:
David MC cable does not rely on the armor for grounding.
...
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Bob,

Some types of MC do rely on the sheath as the EGC. See here for example, and read its statement on "Sheath."

Section 330.108 says

Equipment Grounding. Type MC cable shall provide an adequate path for equipment grounding as required by Article 250.
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It MAY require addtional internal conductors but it doesn't mandate it.
 
iwire

iwire

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Re: MC Cable Connectors

True enough Bob, but in 20+ years in the trade the only times I have seen that type of MC has been in a classroom, where the teacher wanted to show us grounding type MC armor.

From your link.

Applications
C-L-X Okozel control cables are recommended for use in either nuclear powered or fossil fueled generating stations where continuity of service in critical circuits is of primary importance.
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Sounds a little expensive. :)

[ June 23, 2005, 06:29 PM: Message edited by: iwire ]
 
sandsnow

sandsnow

Senior Member
Location
Southern California
Re: MC Cable Connectors

The only Code section I know of that would apply is 300.10 Electrical Continuity of Metal Raceways and Enclosures.

If it were me, I would accept it if you paint it after the connector is properly installed on the cable and you keep the paint away from the contact area where it connects to the enclosure.
 
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redfish

Senior Member
Re: MC Cable Connectors

dpenbert, what applications will you be using the MC for and what trade sizes are you planning on using? :)
 
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southernboys

Senior Member
Re: MC Cable Connectors

bert why prefab if you can guys such as my partner and myself it is quicker for us just to pull off spools. get some wire jacks 1000ft rolls and let your guys go. we can and do pull a unit every day and half then have another crew land and make joints up. so basicly you have 3 2-3 man crews rough these units in. one crew boxes out one crew pulls another crew lands. when we catch up to box out crew well drop back and help either crew
 
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redfish

Senior Member
Re: MC Cable Connectors

I recently did a kitchen remodel in a new 18 story, 66 unit condo complex. To my surprise, I found that all of the 20A/120V circuits were wired using prewired 3/8 BX cable. I have to think that the electrical contractor knew this to be a code violation,however the city inspector passed the inspection. I had to relocate the range and add a few more 120V dedicated outlets and ended up taking out a lot of sheet rock. No way you add circuts to BX. :)
 
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dpenbert

Member
Location
Missouri
Re: MC Cable Connectors

We'll be using MC cable for everything in the units, lighting, power, using 2/C(#12)W/GND, 3/C(#12)W/GND, etc.. We're wanting to prefabricate the receptacles/switches throughout and the lighting/switches. Some electricians are skeptical about using these prefabrication ideas, but the intent is to produce mass quantities of pre-made materials boxes/tails in a controlled environment to decrease field labor time. Thanks for the comments.

-----------
David
 
sandsnow

sandsnow

Senior Member
Location
Southern California
Re: MC Cable Connectors

Originally posted by redfish:
I recently did a kitchen remodel in a new 18 story, 66 unit condo complex. To my surprise, I found that all of the 20A/120V circuits were wired using prewired 3/8 BX cable. I have to think that the electrical contractor knew this to be a code violation,however the city inspector passed the inspection.
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Why do you think this is a code violation? :confused:
 
rbalex

rbalex

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Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Re: MC Cable Connectors

Originally posted by iwire:
True enough Bob, but in 20+ years in the trade the only times I have seen that type of MC has been in a classroom, where the teacher wanted to show us grounding type MC armor.

From your link.

Applications
C-L-X Okozel control cables are recommended for use in either nuclear powered or fossil fueled generating stations where continuity of service in critical circuits is of primary importance.
Click to expand...
Sounds a little expensive. :)
Click to expand...
I have used similar constructions quite often in refinery applications and especially offshore oil-rigs. The trend however, is toward TC-ER [NEC 2005 Sec 336.10(7)]. I suspect it will eventually be recognized in Zone 1, which is what this 15 year process for recognizing Zone wiring practices has been all about in the first place.
 
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redfish

Senior Member
Re: MC Cable Connectors

sandsnow, what makes you think this is a code violation?
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Both the 2002 and 2005 Code prohibits the use of 3/8 FMC or FMT in lengths over six feet. Is this right or wrong? What about your 40% fill? </font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">2002 348.20 (A)2 for FMC and 360.12 & 360.20 for FMT.</font>
<font size="2" face="Verdana, Helvetica, sans-serif"></font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">2005 348.20 for FMC and 360.12 and 360.20 for FMT.</font>
<font size="2" face="Verdana, Helvetica, sans-serif"></font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">Please show me the NEC articles that approve of wiring entire buildings with 3/8 prewired FMC or FMT.</font>
<font size="2" face="Verdana, Helvetica, sans-serif">

[ June 24, 2005, 01:18 PM: Message edited by: redfish ]
 
roger

roger

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Location
Fl
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Retired Electrician
Re: MC Cable Connectors



[ June 24, 2005, 01:26 PM: Message edited by: roger ]
 
roger

roger

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Staff member
Location
Fl
Occupation
Retired Electrician
Re: MC Cable Connectors

Originally posted by redfish:
sandsnow, what makes you think this is a code violation?
Click to expand...
Both the 2002 and 2005 Code prohibits the use of 3/8 FMC or FMT in lengths over six feet. Is this right or wrong? What about your 40% fill? </font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">2002 348.20 (A)2 for FMC and 360.12 & 360.20 for FMT.</font>
<font size="2" face="Verdana, Helvetica, sans-serif"></font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">2005 348.20 for FMC and 360.12 and 360.20 for FMT.</font>
<font size="2" face="Verdana, Helvetica, sans-serif"></font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">Please show me the NEC articles that approve of wiring entire buildings with 3/8 prewired FMC or FMT.</font>
<font size="2" face="Verdana, Helvetica, sans-serif">
Click to expand...
Redfish, you said BX in your earlier post which would be type AC this is not FMC.

See article 320 for AC and 330 for MC.

Roger
 
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redfish

Senior Member
Re: MC Cable Connectors

I just found the article on MC in 2005 330.1.and type AC in 320. Thanks for setting me straight. I'm going to start a big condo complex of 124 units next month and this info helped me greatly. Now I see why the inspector passed it(he knew what he was looking at).Thanks again. :)
 
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