Vault Cleaning

[itsmoked]

In-ground utility transformer vaults and splice pits are filling up with dirt from mud and water coming in thru the lids and conduits. In an effort to clean this dirt out a Hydro-vac truck will be used to excavate this dirt out as it is loosened with high pressure water (pressure washer). All this is done with the circuits live.

Does this sound reasonable? Would you do this?

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[davidbeach]

Are submersible connectors rated for pressure washing? I kind of doubt it; stand back and watch the fire works.

 

[DanDel]

Honestly, itsmoked, I can't imagine a more dangerous way to clean live components except maybe to go in the vault and hit the splices with an axe.

Someone may say that there is already plenty of water in there, but using high-pressure water jets will definitely disturb any insulation that isn't armor-plated. If it doesn't blow up, it will at least conduct up the water stream to whoever is holding the jet.

Anytime I'm in a vault, I definitely don't touch any live cables/splices/etc.; I don't even look at them too hard!

 

[Skogsgurra]

Did they choose you to do the cleaning? I guess they looked for someone with an appropriate handle ;-)

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[stevenal]

Hydrovacs are commonly used to expose buried, energized conductors complete with splices. If there are no elbows in the vault I don't see a problem. As always, workers need to be properly trained.

 

[BJC]

stevenal
I have never heard of anyone who could be trained to resist 7200 volts to ground. <%^) .
In the years it takes to fill a vaut with and dirt and mud the cable and connectors can deteroriate to the point that a small movement can cause a fault. I have been there when a lineman with a hotstick tried to opened an older load break elbow. The vault was dirty but fairly dry. As soon as he put the stick on the pull eye there was a big bank, lots of blue smoke and dirty underwear.
Everything in an underground system is designed to function dirty and underwater. Unless itsmoked is putting glass ocvers on vaults leave them alone.

 

[stevenal]

I think the training is meant to avoid the voltage. Anyway it keeps you on OSHA's good side.

And why should the insulation be any better outside the vault?

After Davidbeach's comment, I specifically excluded elbows.

I agree the presence of dirt by itself is not a problem. I assumed this was to be done prior to other needed work.

Outside the vault, the old method involved careful hand digging to expose the cable. The Hydrovac is a safer alternative.

 

[stevenal]

http://www.badgerinc.com/solutions/utility.html