# Class I switch corrosion



## 3xdad (Jan 25, 2011)

Not sure how old this install is. Water is getting in.

Switches failed and one cover is seized.

i will be replacing the switch kits at $129/per:blink: and at least cleaning out the box.

What's your SOP to rehab this setup? Re-do sealoffs? Isn't the switch supposed to be housed in a gasket?

Thanks.


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## Dennis Alwon (May 9, 2009)

I believe there should be a gasket for those covers so I would at least replace them. I don't think the sealoff needs to be changed nor do I think the jb needs to be messed with other than cleaned out


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## Wirenuting (Sep 12, 2010)

I swap out the gasket, cover and screws. A little cleaning of the box and I call it good. They last about 10 to 15 years. 
I find the worse ones inside fuel bunker rooms we have. Those are on outside walls and seem to condense quicker.


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## JohnJ65 (May 8, 2008)

Most explosion proof boxes like these do not have a gasket. They are machined tight enough to seal when bolted together. At least most of the boxes I have installed were that way. 
I used to see a lot of condensation issues with old explosion proof conduit and boxes so we would install a explosion proof drain on the bottom and a vent on the top. Unfortunately it does not look like you can do that in this situation because there is only the two hubs. The water is probably seeping in around the threads at the top under the seal off. Try gooping it up with some silicone around the top???


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## 3xdad (Jan 25, 2011)

Here's the older C/H light above the switches which finding the globe & guard is a little difficult.

A new EV series light will run around $520.


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## Dennis Alwon (May 9, 2009)

You could throw a bead of silicone on the top portion of the box


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## Wirenuting (Sep 12, 2010)

The older Cross Hines DS line I run across here all have the cork gasket.


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## don_resqcapt19 (Jul 18, 2010)

Dennis Alwon said:


> I believe there should be a gasket for those covers so I would at least replace them. I don't think the sealoff needs to be changed nor do I think the jb needs to be messed with other than cleaned out


I have never seen that design box with a gasket. There are some Class I enclosures that use gaskets, but I have never seen that type with a gasket.

You do need to look closely at the listing information for Class I enclosures. Some are only NEMA 7 and not suitable for use in a wet location. If you need to use it in a wet location it needs to have an additional listing such as NEMA 4.


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## 3xdad (Jan 25, 2011)

don_resqcapt19 said:


> I have never seen that design box with a gasket. There are some Class I enclosures that use gaskets, but I have never seen that type with a gasket.
> 
> You do need to look closely at the listing information for Class I enclosures. Some are only NEMA 7 and not suitable for use in a wet location. If you need to use it in a wet location it needs to have an additional listing such as NEMA 4.


i do believe now, that the type in the pictures did not originally have a gasket, but check out the (newer ?) design on page 2 of this PDF. Pretty slick.

http://www.cooperindustries.com/con...s/control/eds-snap-switch-control-station.pdf

Good call don, i found this today in an Allen Bradley doc.



> Type 7 enclosures are designed to meet explosion-proof requirements. They are for indoor
> use in locations classified as Class I, Groups A, B, C, or D. Type 7 enclosures are designed
> to be capable of withstanding the pressures resulting from an internal explosion of
> specified gases, and contain such an explosion sufficiently that an explosive gas-air
> ...


Is it possible that thousands of these boxes installed outdoors aren't wet loc.?


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## don_resqcapt19 (Jul 18, 2010)

3xdad said:


> i do believe now, that the type in the pictures did not originally have a gasket, but check out the (newer ?) design on page 2 of this PDF. Pretty slick.
> 
> http://www.cooperindustries.com/con...s/control/eds-snap-switch-control-station.pdf
> 
> ...


I don't see a gasket in that PDF. 

If an explosion proof enclosure has a gasket, it will normally be an "O" ring type gasket that is installed in a shallow grove in one of the two parts, normally near the outer edge of the sealing surface. You still need the smooth finished metal to metal contact to provide the explosion proof part of the seal, with the O ring providing the water sea.

Yes, I think that there are many explosion proof enclosures installed in wet locations that are not rated for wet locations. Most of the newer enclosures are rated for both, but a number of the older ones were not.

As a side note, the rust on the two surfaces in the original picture is likely enough to prevent the explosion proof enclosure from doing its job in the case of an explosion within the enclosure.


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## 3xdad (Jan 25, 2011)

don_resqcapt19 said:


> I don't see a gasket in that PDF.


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## don_resqcapt19 (Jul 18, 2010)

3xdad said:


>


That is not a gasket. That is another ground surface seal for a "factory sealed" device. When using a factory sealed device, the actual explosion proof seal is between the cover and the piece you called the gasket. A factory sealed device is really a box within a box. The wires are potted to provide the seal where they leave the factory sealed device. The use of this type of device eliminates the need for a conduit sealing fitting at the box.


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## 3xdad (Jan 25, 2011)

i need help on this light. It's a Crouse Hinds EVJ102 mounted on a EVJ2 bulkhead.

The globe and guard are missing.

My SH says EVJ line are not available and a new EVI is $475 with 4 to 6 weeks lead.:blink:

Would you guys try to find a globe and guard or just replace? If replace, where are they available now?

Thanks.


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## ampman (Apr 2, 2009)

3xdad said:


> Not sure how old this install is. Water is getting in.
> 
> Switches failed and one cover is seized.
> 
> ...


Is the neutral supposed to be switched also


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## erics37 (May 7, 2009)

ampman said:


> Is the neutral supposed to be switched also


I'm thinking that wire used to be yellow or something :laughing:


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## ampman (Apr 2, 2009)

erics37 said:


> I'm thinking that wire used to be yellow or something :laughing:


No I remember that in certain ex- proof situations both the hot and neutral are supposed to be switched


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## glen1971 (Oct 10, 2012)

I have never seen a EDSC box with a gasket between the device and the box, but that isn't saying that they didn't have one at one point.. You have to be careful about what you put on the machined faces of the boxes and devices because you it will be against the manufacturer's specs.. 

On one job there was a Crouse Hinds grease that we had to apply to the box face.. PITA with the dust in the area..

What I do in this case is to replace the switch, and clean up the box as best I can with some brake kleen and a rag.. Then reinstall the switches and add a Crusader Cover... The gasket goes on past the front of the box and you shouldn't have the issue in the future..

http://www.crusaderindustries.com/csopen.htm

A little tip - add a bit of STL into each screw hole.. Makes the next removal a little easier..


As for the light fixture, I'd go with the EVI and be done with it.. That is about typical for a lead time..


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## erics37 (May 7, 2009)

ampman said:


> No I remember that in certain ex- proof situations both the hot and neutral are supposed to be switched


Yeah, switched simultaneously. Two separate toggle switches aren't simultaneous.


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## ampman (Apr 2, 2009)

erics37 said:


> Yeah, switched simultaneously. Two separate toggle switches aren't simultaneous.


514.11 I think ,if it's for motor fuel


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## erics37 (May 7, 2009)

ampman said:


> 514.11 I think ,if it's for motor fuel


I didn't argue that. I stand by my assertion that the wire attached to the switch is (or used to be) a yellow ungrounded conductor. You can see a couple of white-ish wires stuffed in the back of the box; presumably neutrals.

Furthermore, even if it was a switched neutral, it would be required to be switched simultaneously with the associated ungrounded conductor(s). Having two separate toggle switches is definitely not simultaneous.


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## 3xdad (Jan 25, 2011)

Guys, i'm standing right here.:laughing:

The switch on the left controls the 120V light in this thread. The N's are nutted in the box, black to switch and what i believe is two whites up to the light (although plausible it was a yellow). Maybe they ran out of black, who knows.

The switch on the right switches a relay that controls an LP pump motor.

A DPST switch would do the simultaneous thing, right?


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## erics37 (May 7, 2009)

3xdad said:


> A DPST switch would do the simultaneous thing, right?


Yeah if it was rated for the voltage of course.


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## ce2two (Oct 4, 2008)

Dennis Alwon said:


> You could throw a bead of silicone on the top portion of the box


I use alot of silicon ,because at any time in the future, just scrape away and reapply more..I also silicon the screw threads, screws on switchs to keep terminals from turning green and creating a high resistance to current flow.


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## glen1971 (Oct 10, 2012)

ce2two said:


> I use alot of silicon ,because at any time in the future, just scrape away and reapply more..I also silicon the screw threads, screws on switchs to keep terminals from turning green and creating a high resistance to current flow.


I hate it when guys over use silicone.. Especially when they put it on the face of the switch and the box.. Kinda makes it installed against the manufacturer's directions.. Use drains where needed and approved covers when outside.. Switch placement can play a big part - not right below the eaves, under an ice shield, etc....


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