# Mi cable support



## Dennis Alwon (May 9, 2009)

Mike art. 332 is for mi cable and art. 332.30 states 6'


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## wildleg (Apr 12, 2009)

are you familiar with one and two-hole straps ?

BTW, what exactly is an "installer" ?


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## Tom45acp (Sep 6, 2011)

Normally, you would support MC within 12" of a box and every 6 feet. If the manufacturers instructions state that support is required every 2 feet, then 2 feet it is. 110.110.3(B)


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## wildleg (Apr 12, 2009)

what does that have to do with MI ?


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## brian john (Mar 11, 2007)

Tom45acp said:


> Normally, you would support MC within 12" of a box and every 6 feet. If the manufacturers instructions state that support is required every 2 feet, then 2 feet it is. 110.110.3(B)


MI=Mineral Insulated, a conductor (1 to 7 depending on size) in a copper jacket surrounding by a mineral for insulation. Typically w=utilized for Fire Pumps to achieve a predetermined fire rating.

We have used strut, with insulated stand off to avoid galvanic action (required by specifications), Stand offs on 3/8" rod, or two hole straps on the wall.

http://www.tycothermal.com/assets/N...Datasheets/Products/216/015U-Sys1850-0102.pdf

http://www.micable.com/mic05.html

WHAT I DID NOT KNOW.


Radiation resistant

Magnesium oxide, the insulation in mineral insulated cable, provides superior radiation resistance over any other material and for this reason, MICC cable assemblies are an excellent choice for nuclear power plant applications.


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## MDShunk (Jan 7, 2007)

Did all the emergency lighting in a YMCA with type MI cable. Misery! Used a 'P' shaped strap that was rubber coated. I'll see if I can find a pic.

Edit:
Sorta like these below. They make them similar for strut.


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## brian john (Mar 11, 2007)

MDShunk said:


> *Did all the emergency lighting in a YMCA* with type MI cable. Misery! Used a 'P' shaped strap that was rubber coated. I'll see if I can find a pic.
> 
> ]


Specified I assume? Or Why.

I did some testing in a building that had 500 kcmill MI, talk about hard work installing a 200' run. Never saw the electricians but I assume Popeye size arms.


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## MDShunk (Jan 7, 2007)

brian john said:


> Specified I assume?


Yeah. Historical building. Plus, it is one of the few YMCA's left that homeless people can still live at, so it was a pretty high-density dormitory. This stuff was like copper water pipe size. No problems bending. Used a plumber's spring bender for most of it, and the occasional knee.


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## MDShunk (Jan 7, 2007)

The thing that sucks about MI (for me) is the freaking hour per termination it takes to put the special fitting on properly. Well, maybe not an hour, but not the 10 seconds it takes to makeup romex or MC.


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## brian john (Mar 11, 2007)

MDShunk said:


> The thing that sucks about MI (for me) is the freaking hour per termination it takes to put the special fitting on properly. Well, maybe not an hour, but not the 10 seconds it takes to makeup romex or MC.



We terminated 4/0 and it took almost an hour.

Suggestions, megger cable the second it is off the truck
Megger immediately after installation
Megger after termination.

Keep the ends sealed up completely during installation.

We had some get wet and had to dry it took several days. Per the manufactures directions.


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## MDShunk (Jan 7, 2007)

I also found it easier to connect to the boxes before they were fastened down; more or less in mid air. Connect cable fitting to cable end, connect to box, then screw box fast. Probably looked like a ****** when I was doing it, but it seemed to work well.


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## mike8487 (Mar 29, 2011)

*drip/expansion ?*

thanks for all the info men. I was wondering about the use of loops in the run to provide expansion and i think i have seen some pics using loops at termination to provide flex, much the way we might use greenfield. i'm sure the fire pump will vibrate considerably upon use. i suppose it might help at terminating also.


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## brian john (Mar 11, 2007)

mike8487 said:


> thanks for all the info men. I was wondering about the use of loops in the run to provide expansion and i think i have seen some pics using loops at termination to provide flex, much the way we might use greenfield. i'm sure the fire pump will vibrate considerably upon use. i suppose it might help at terminating also.


Once you terminate in the fire pump room, to the fire pump controller you can change to standard wiring methods.


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## mike8487 (Mar 29, 2011)

*controller*



brian john said:


> Once you terminate in the fire pump room, to the fire pump controller you can change to standard wiring methods.


i have seen all to often lately that the pump comes already wired from the control panel. the panel and pump are mounted on a metal skid plate with welded upright angles. the control panel is mounted to the angles and the GC just installes the skid plate. the electricians only run the feed to the panel. there may be some auxillary equipment brought to the control panel, but that would located elsewhere in the field.


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## Tom45acp (Sep 6, 2011)

Tom45acp said:


> Normally, you would support MC within 12" of a box and every 6 feet. If the manufacturers instructions state that support is required every 2 feet, then 2 feet it is. 110.110.3(B)


Definitely had a senior moment & a typo, 110.3(B) certainly applies, manufacturers directions must be followed.


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