armor power cable through floor?

[rinella]

what is the best way to "armor" a 4ga power cable so it doesn't short on the sheet metal floor?

Thank you.

 

[LeeRevell]

First I would put a rubber grommet on the hole in the sheet steel, to protect from the sharp edge.

 

[Optimistic Paranoid]

Lee is absolutely right about the grommet. That is a necessity.

If you want to take it a step further, you could try to find a bit of rubber fuel or vacuum line the right diameter to fit over the wire. Get three or four inches of it and split it lengthwise, wrap it around the wire and tape it into place.

Naturally, you need to size your rubber grommet to accommodate the outside diameter of the hose in that case.

Regards
John

 

[highdesertranger]

lee and paranoid are right use a grommet. plus extra protection of a rubber hose. I use this method myself, or you could use conduit emt or pvc. I have done it this way if I wanted a bullet proof system. highdesertranger

 

[66788]

Lee, Paranoid, and HighDesertStrangler are right, use a grommet.

Doesn't this sound like something from Blazing Saddles? Yes Mr. Johnson....

 

[Spaceman Spiff]

A grommet is the minimum protection. Make sure the hole doesn't have any burrs or sharp edges. Grommets are soft rubber, cut easily.

Next best is adding a rubber hose around the wire where it goes through the sheet metal, as Optimistic Paranoid says. Do this if you drive on dirt roads a lot or otherwise experience a lot of vibration.

Highdesertranger's suggestion of using metal or hard plastic tube for protection is excellent, just have to make sure it doesn't vibrate out of the hole (restrain on both sides of hole).

Best method for ensuring both a seal and protection from shorts is a bulkhead connector. Usually only used when you need to completely seal the opening (fire code, water or toxic fumes penetration) or have serious vibration (like driving fast on washboard roads).

-- Spiff

 

[highdesertranger]

ha ha, space man you can get serious vibration on a washboard road at any speed. it's harmonics, whatever speed it happens to be. I have been on roads that 10mph would shake your fillings right out of your teeth but speed up to 20mph and it smooth's right out. this works the other way too, sometimes slowing down works better. depends on each individual road. highdesertranger

 

[nowhhs]

Any vibration that will cut through your insulated cable WILL eventually cut through rubber hose, inner tubes, and even grommets. I've taken apart more than a couple of worn out grommets. Your best bet is an actual strain relief like this: http://www.heyco.com/Strain_Relief_Bushings/ . That is the one I use and it works by completely immobilizing the wire so that it can't rub against anything. Another option is a romex strain relief that you can get at Home Depot, but they don't have any provision for weatherproofing, so water can and will leak through it.

 

[nowhhs]

I wasn't referring to a chase nipple (is that what those things are called?), but rather one of these: http://www.gordonelectricsupply.com...~0~ID~,Conduit...Fittings,NM.Romex.Connectors . They will support the wire, but you're right, they won't seal the hole, which is what I said in my original post.

 

[anm]

I wasn't referring to a chase nipple (is that what those things are called?), but rather one of these: http://www.gordonelectricsupply.com...~0~ID~,Conduit...Fittings,NM.Romex.Connectors . They will support the wire, but you're right, they won't seal the hole, which is what I said in my original post.

How about one of those mechanical connectors and RTV to seal it?

 

[highdesertranger]

I don't care for those that nowhhs posted for use on vehicles. because they work by pinching the wire between 2 pieces of metal, then you add the vibration and it damages the insulation. if left long enough it will short. highdesertranger

 

[nowhhs]

The way insulation is damaged is via rubbing, not squeezing. Vibration won't hurt it if the wire is firmly clamped. But to each his own. And yes, RTV would seal it nicely, especially if you smear it in from both sides.

 

[anm]

I don't care for those that nowhhs posted for use on vehicles. because they work by pinching the wire between 2 pieces of metal, then you add the vibration and it damages the insulation. if left long enough it will short. highdesertranger

Yes, I understand what you're saying...