Insulating Armoured Cable Connector?

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Bigjabe

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Hi all,

I have a situation (see my other recent posts!) where I need to insulate the cable's armor from the equipment enclosure. I haven't been able to find such a product yet, I was wondering if anyone has heard of one?

The best I can think is to strip back the armor, then use a tray cable connector on the inner jacket... but that seems kinda hokey.

Thanks!
 
Code wise the cable needs to terminate in a connector listed for that cable. I don't see how you can do this in a code compliant manner except maybe if you used an IG receptacle with an IG-EGC in the cable.
 
infinity said:
Code wise the cable needs to terminate in a connector listed for that cable. I don't see how you can do this in a code compliant manner except maybe if you used an IG receptacle with an IG-EGC in the cable.
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No receptacles here, it's 250kcmil 15kV cable! The ground grids on each end of the cable need to stay isolated from each other, so can't have the armor connecting them. Might have to use unarmored cable so it's not an issue..
 
Bigjabe said:
No receptacles here, it's 250kcmil 15kV cable! The ground grids on each end of the cable need to stay isolated from each other, so can't have the armor connecting them. Might have to use unarmored cable so it's not an issue..
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That would have been excellent information to have in the original post. I don't see a solution with armored cable; yet.
 
Bigjabe said:
No receptacles here, it's 250kcmil 15kV cable! The ground grids on each end of the cable need to stay isolated from each other, so can't have the armor connecting them. Might have to use unarmored cable so it's not an issue..
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OK. Then disregard my first response.
 
Bigjabe said:
No receptacles here, it's 250kcmil 15kV cable....
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No prob Big Guy, can do:

giant-3-way-plug-pma-edlow-600.jpg
 
Bigjabe said:
Hi all,

I have a situation (see my other recent posts!) where I need to insulate the cable's armor from the equipment enclosure. I haven't been able to find such a product yet, I was wondering if anyone has heard of one?

The best I can think is to strip back the armor, then use a tray cable connector on the inner jacket... but that seems kinda hokey.

Thanks!
Click to expand...

Can you terminate into a fiberglass or PVC j-box then run a nipple into your enclosure?
 
MattS87 said:
Can you terminate into a fiberglass or PVC j-box then run a nipple into your enclosure?
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I was thinking something like that too. Can’t say i’ve ever terminated a big cable like that on a non-metallic enclosure before - something feels off about it but I’m not sure if there are any actual problems. I prefer that solution than the stripping back the armour idea!
 
Bigjabe said:
I was thinking something like that too. Can’t say i’ve ever terminated a big cable like that on a non-metallic enclosure before - something feels off about it but I’m not sure if there are any actual problems. I prefer that solution than the stripping back the armour idea!
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If you do go this route make sure you size the box correctly using the 6x or 8x rule. You would use your standard connectors and you could possibly mount a terminal block inside or just use Polaris connectors. What is this for anyways?
 
MattS87 said:
If you do go this route make sure you size the box correctly using the 6x or 8x rule. You would use your standard connectors and you could possibly mount a terminal block inside or just use Polaris connectors. What is this for anyways?
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I wouldn’t even bother with any terminal blocks, just using the box as a place to terminate the armour. The inner jacket would continue on in to the equipment terminal box. It’s from a transformer at the feed end (that’s where this plastic box would be, mounted just under the terminal chamber) then going off to some switchgear, the armour would be grounded at that end. If you’re interested why I’m isolating the armour check out the thread here in the grounding forum on underground mine grounding - pretty cool I think ?
 
jumper said:
Iggy, don’t make me come find you.:)

Mines here again son. Pay attention.

Youse sposed ta chime in here!
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haha i should have just asked this question in the other thread where Iggy was already fully engaged. I just... didn’t want to bother him with such minutiae :roll:

Edit: that being said, it would be great to start a new sub forum for complex engineering issues here. I know when I first started out doing major power system studies, intricate relay settings, SCADA networks... it would have been great to have this kind of resource. As protection becomes more and more like proprietary computer programming, us engineers need more places to discuss things. I could still use some help from time to time :ashamed1:
 
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Bigjabe said:
haha i should have just asked this question in the other thread where Iggy was already fully engaged. I just... didn’t want to bother him with such minutiae ?
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You do not need to bother him, I will.:D

Seriously though, we are glad you are here and Iggy is happy to help.

That is what this forum is for.

We live for unique problems and solutions.
 
jumper said:
You do not need to bother him, I will.:D

Seriously though, we are glad you are here and Iggy is happy to help.

That is what this forum is for.

We live for unique problems and solutions.
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Cheers man! This is probably the only industrial discipline where we really come across unique situations all the time. Maybe I’m just a rebel, but I’m always on the horn with local inspectors getting their buy-in for stuff that doesn’t quiiiiiiite fit.. much more interesting (and productive) hacking it out on this forum though!
 
Not sure if you saw my edit above.. but an advanced engineering sub would be fantastic. Perfect example, we got this motor with a horrific protection scheme right on the nameplate. I’m paraphrasing but something like “motor is allowed 2 starts except if winding temp exceeds 93.7c then 1 start is allowed assuming jupiter is aligned with venus and if not then 3 starts allowed but only if previous start was in a different lunar cycle otherwise must wait 4 hours and 13 minutes or until the raven flies overhead”

it would have been great to have some folks to bounce ideas off! The current engineering sub is dominated by things like domestic load calcs, and I think an advanced engineering sub would really be a great resource and good to attract higher level expertise.
 
Bigjabe said:
Not sure if you saw my edit above.. but an advanced engineering sub would be fantastic. Perfect example, we got this motor with a horrific protection scheme right on the nameplate. I’m paraphrasing but something like “motor is allowed 2 starts except if winding temp exceeds 93.7c then 1 start is allowed assuming jupiter is aligned with venus and if not then 3 starts allowed but only if previous start was in a different lunar cycle otherwise must wait 4 hours and 13 minutes or until the raven flies overhead”

it would have been great to have some folks to bounce ideas off! The current engineering sub is dominated by things like domestic load calcs, and I think an advanced engineering sub would really be a great resource and good to attract higher level expertise.
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Not sure what you use for motor protection in that case but worked at a place that used this http://www.gegridsolutions.com/multilin/catalog/339.htm
Application was a hog motor that couldn't be started more than 2x/hr among other things
 
MattS87 said:
Not sure what you use for motor protection in that case but worked at a place that used this http://www.gegridsolutions.com/multilin/catalog/339.htm
Application was a hog motor that couldn't be started more than 2x/hr among other things
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Yeah starts/hr is a pretty standard function - for this damn thing we had criteria based on ambient and highest winding RTD, it was crazy (I’ll try to find it...). We had an SEL 710 and it was not easy at all. Would have been impossible with the 339 you linked, but the Multilin 869 or M60 would have made it simple.
 
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