Weather Proof SS Cabinet Entry

Murray Ritchie

Have a stainless steel (SS) cabinet which will be housing a communication system. The SS is about 1/16". Need to enter the cabinet with 3/4" pipe, and continue it inside the enclosure.

Would like to get some opions on how to accomplish this while maintaining a weather proof rating. Also, suggestions on how to a get a clean hole through the SS.

Thanks in advance for your input.

neolitic

Step bit?
Or this?
http://www.mygreenlee.com/Products/m...c_number=02408

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TxElectrician

stainless will ruin a step bit fairly quick. Drill a pilot hole, then 3/8"bit, KO 1/2" then 3/4". Hydraulic cutter will work best. Myers hub to maintain weather proof rating.

Murray Ritchie

Have considered both of these options. Believe that the step bit would be round be for being able to complete. Possibly with two or three it might go. Also thought that it might temper the ss from the heat. The ss is a harder steal than the bit.

Not sure if the slug buster would be much different. Have you tried with success? Believe, but not certain, that the ko's are of softer steal too.

Murray Ritchie

TxElectricain....with the myres, there is a female end on the outter surface which will give provission for a pipe fitting. But a lock nut on the inside. Would you suggest a coupling instead of the locking nut?

TxElectrician

As far as the slug buster, I have had success knocking out SS enclosures. Have also broken a few dyes! I think you should be able to screw a threaded coupling onto the hub below the lock ring.

neolitic

I first bought the knock-out cutter
to do 50 S.S. sinks in a school
(someone forgot about soap dispensers.)
Used the same one for years
after that job.
Commercial sinks are fairly tough
steel.

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Celtic

A Meyer's hub if RMC
Raintight Compression if EMT


1 1/8" hole saw....slow and hard....very slow, very hard.
You will know when you have right combination of speed and force when you send the pilot through ~ it should peel like an apple.
Maintain that speed/force with the hole saw.

Drilling fast just burns the bit.
Not enough pressure just burns the bit.

...better get 2.

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TxElectrician

[quote=Celtic;626284]A Meyer's hub if RMC
Raintight Compression if EMT


A compression fitting does not make the enclosure entry weatherproof, just the fitting. A hub will be needed regardless of conduit type.

TxElectrician

Sorry, I am assuming he is entering on the top of enclosure.

Celtic

Really?

What's this all about, then?
"Raintight" compression type EMT fittings for use in wet locations




TC112A-RT
Steel City® Die Cast & Steel Fittings
3/4" Compression Connector, Steel-Zinc Plated, Raintight and Concrete tight. For use with EMT Conduit.

Product Overview Click Here


If you're still not satisfied, toss a sealing lock nut on it.

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TxElectrician

Celtic, I have not used or seen the fittings you've shown, but if they do in fact make the enclosure entry weatherproof why are all the pictures in the product overview showing them entering a threaded hub?

mickeyco

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ScipioAfricanus

Get a plasma cutter, use a template with it if you have a bunch of holes. Then clean up the mess.
Andy.

Celtic

Probably because it's an "overview" ...the "overview" also doesn't say how to tighten the fitting.

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TxElectrician

not all are created equal

Celtic, thanks for the information. After doing a little research and checking the 3 local supply houses, all of which are large chains, not one stocks "raintight " fittings. All are "concrete " tight.

One of these distributors has 90 stores thru out the south and stock the raintight fittings in 3. I have been assured the local branch will begin to stock them.

Like I said, I have not used or seen a fitting like you posted. Could be because I am still green, only have been in the trade since '78.

Every inspector I have ran accross in that time has accepted "concrete tight" compression fittings as raintight, but have required a threaded conduit hub for the connection into an enclosure.

TxElectrician

That mat explain all the P traps I put in my conduit runs

mdshunk

Pretty long thread about drilling a hole... Seriously Murray, electricians do this every day. I install about a dozen traffic signal setups and pedestrian crossing signals a year, and stainless steel is the order of the day. For 3/4" pipe, a step bit, a hole saw, or a slug buster will all work. No problem. Go slow, use lube if you feel like it, but it's not rocket surgery. Stainless is hard on bits and such. That's just how it is.

If you're entering the top or sides, use a Myers hub. This is sorta electrician 101 stuff. There are some tricky fittings out lately that might work, but for decades the Myers hub has been the fitting of choice for that since before Edison invented electricity. If you're coming in the bottom, you need no special fitting at all, since it doesn't rain upside-down.

macmikeman

This is dragging up an older post and please bear with me about it , but I read it recently while doing a little research. UL has published an article about this very thing in ul code corner and states that myers hubs are not acceptable for use with emt due to the threading. They are for rigid and IMC conduit, not emt. When you see a myers in the top of a box with emt connector screwed into it its wrong, although inspectors everywhere will disagree with me about it cause its how they were taught to bring emt into 3r boxes along with all the rest of us. The raintight connectors are the only listed method. I posted about this recently, here is the linkhttp://www.iaei.org/magazine/?p=1556