# stopping steam entering a disconnect



## gpop (May 14, 2018)

On a lift station with a concrete slab as a lid they drilled a 3" hole to allow the pump cables (s-o cord) to exit. The plan is to mount 2 x 60 amp disconnects for the pumps. 

The problem is that the lift station has steam and hot water discharged into it sometimes so if i use flex to protect the so cord this allows moisture to the disconnect. There is grass around the lid and the hole is near the edge so exposing the s-o with out protection would be a bad idea. 

Im figuring mounting a j-box over the hole then ridgid conduit to the disconnect and using a gas seal off (thhn between the disconnect and j-box). The pump connection would then be made in the j-box. 
Worst case i see is if the connection burnt up and there wasn't enough wire to remake the termination i would have to replace 4' of conduit and install a new gas seal. 

We have tried non permanent sealing material on other lift stations with limited success (duct seal doesn't like steam). The pumps life expectancy is 1-2 years and is a emergency when it fails so pulling the s-o cord to the disconnect then using a seal off would be a pain to deal with. 

Any better ideas?


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## Jlarson (Jun 28, 2009)

Can you run a sleeve up to a point under the discos and end the sleeves with a cord grip then put a cord grip in the disco. That way you have an air gap.


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## 460 Delta (May 9, 2018)

I’m thinking like jlarson here, a sleeve of 1 1/2” or 2”, a LB and a ell then a female pipe adapter to a cord grip then a cord grip in the disconnect. If the LB is oversized enough, you can make up the connections in it.


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## glen1971 (Oct 10, 2012)

Why replace the conduit? If the wires burn up, drop the conduit, spin the seal off, pull the old wires out with the seal, install a new seal, replace the conductors and pour the seal.
Can you leave a loop in the junction box for some slack in the conductors?
Were you planning to have a drain (ECD15) in the junction box?


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## MXer774 (Sep 1, 2014)

Have a look into CSME / CSBE Seals. These are speced on our lift stations. Typically, we sleeve a 2 1/2 through the well, route the pumps SO cord through it. And seal with these CSME. You will need to know the O.D. diameter of the cable. Ours are made to order, not cheap, and have a long lead time.


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## Wiresmith (Feb 9, 2013)

have you used polywater fst sealing or zipseal, they are also re-enterable and supposed to hold a decent amount of pressure.


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## Helmut (May 7, 2014)

Foam won't work?


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## gpop (May 14, 2018)

glen1971 said:


> Why replace the conduit? If the wires burn up, drop the conduit, spin the seal off, pull the old wires out with the seal, install a new seal, replace the conductors and pour the seal.
> Can you leave a loop in the junction box for some slack in the conductors?
> Were you planning to have a drain (ECD15) in the junction box?


Good points about the conduit and yes i would add a drain.


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## gpop (May 14, 2018)

Helmut said:


> Foam won't work?


I really should have added more detail but i didn't want to over complicate things.

On a cold lift station foam works and is good for a year or 2 but on a hot lift station in a orange juice plant it doesn't last long at all.

Oranges have a oil in the skin that vaporizes at a low temperature and will eat rubber and foam.
In a cold lift station this doesn't cause a problem but in a station that receives hot water during a clean up it tends to vaporize and rise to the top of the station. Its at a low enough ppm so it is not a fire hazard but it will slowly eat foam. (there are also other chemicals that are used that may be responsible for eating foam when used as a seal)


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## paulengr (Oct 8, 2017)

Even if you seal it perfectly you get condensation when it's humid and the temperature drops. NEMA 4X panels in an open field get condensation. Short of hermetically sealed and nitrogen purged you cannot totally stop moisture. Decreasing ingress from the conduit to the wet well does help a lot just understand that's usually more about decreasing H2S than H2O. If you see corrosion and the copper, silver, and nickel is BLACK, not greenish or grayish, that is H2S not H2O. H2S attacks electrical metals aggressively down to 0.1 ppm and you can only smell sewer gas to 1 ppm so you might not even notice.

With H2S use noalox or electrical joint compound on everything and potentially paint it all with liquid electrical tape. Seal up openings as good as you can with foam or better yet duct seal which is easy to remove. Buy conformal coated equipment when available. It is possible to survive up to 10 ppm in phosphoric acid plants. They sometimes have to go to activated carbon filters though even after sealing up everything.

If you want to deal with condensation there are really 3 options. First you can live with it. Put in the NEMA 4 or 4X panel BUT drill a 1/8" hole in the bottom back corner to allow it to go somewhere and also give it some air to dry out. Believe it or not a sealed outdoor panel is sort of a bad idea but the NEMA 3R panels might be too open to your liking. If you want to get fancy put in a cheap plastic breather. Next up, use the hydraulic reservoir filters with the silicone gel that absorbs all incoming moisture as the panel breathes. This gets you to very low humidity levels but it's consumable. Must replace. Finally avoid condensation altogether by installing a panel strip or coil heater to keep it above the dew point. It burns electricity instead of silica gel.

Take it from me. The coastal towns around me have hundreds of lift stations. The Norfolk metro area has over 4000 lift stations. It's all going to corrode or wear out and need replacement in about 20 years anyways so the goal is just to extend component life to a natural old age failure.

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## glen1971 (Oct 10, 2012)

If you are concerned about wire and splice degradation from corrosive gases, try installing these.
http://www.cooperindustries.com/con...re-accessories-corrosion-inhibitor-device.pdf


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## gpop (May 14, 2018)

glen1971 said:


> If you are concerned about wire and splice degradation from corrosive gases, try installing these.
> http://www.cooperindustries.com/con...re-accessories-corrosion-inhibitor-device.pdf


That's different. I would have to believe they work before going to the hassle of filling in the paper work for the msds review.


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## glen1971 (Oct 10, 2012)

gpop said:


> That's different. I would have to believe they work before going to the hassle of filling in the paper work for the msds review.


I've seen them spec'd on jobs and installed before I got there.. I'm not 100% sure of their effectiveness, but some I've found look like new years later, with no sign of issues on the wires and some are discolored and hard when I find them to fix a broken wire in a junction box.. 
I haven't seen an annual PM yet to check/replace any, no matter where I've worked. I'm assuming most people don't know they are there..


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## paulengr (Oct 8, 2017)

They're sacrificial anodes of I think pure silver. Tried them in a panel above a wet well that does not have submerged inlets so it's real bad. They didn't do anything at all including didn't see any corrosion on them.

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## Wiresmith (Feb 9, 2013)

crouse hinds speed seal might work. you could use a sealing hub, you don't absolutely need a seal off.

http://www.cooperindustries.com/con...mpoundsandfiber/chico_speedseal_compound.html


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