Any medium voltage guys here?

[wawireguy]

Is it safe to be in a vault with 13.2K volts if you are not doing any work on the live system? The work will consist of core drilling and pulling conductors into the vault.

I'm not familiar with the type of connections that are made in this vault. I've heard them called load breaks. They are installed in rails on the wall. Almost looks like plugs into unistrut.

I'm concerned that there isn't anyone on this job that is qualified to assess the hazards and that there is no plan for working safely in this environment.

 

[A-F-E]

NFPA 70E for working on live parts. But you still want to make sure you tell your loved ones that you care about them and make sure your life insurance is paid up.

Other than that you should be fine.

 

[zog]

Is it safe to be in a vault with 13.2K volts if you are not doing any work on the live system? The work will consist of core drilling and pulling conductors into the vault.

I'm not familiar with the type of connections that are made in this vault. I've heard them called load breaks. They are installed in rails on the wall. Almost looks like plugs into unistrut.

I'm concerned that there isn't anyone on this job that is qualified to assess the hazards and that there is no plan for working safely in this environment.

I spend 80% of my time around MV. I cant answer your question without a lot more details. If you are so unsure you probaly should not be working in there, you need to know the LAB, RAB, and PAB for shock protection and the AFB and Ei's you may be exposed to.

Your concerns are justified, et someone qualified to access the work area and job scope.

 

[wawireguy]

This pretty much reinforces my view that there is no safe way for us to do this work while the vault is live. I think I'll keep myself well out of that vault.

 

[charlie b]

I do some design work for MV installations from time to time. I was walking around in just such a vault only a month or so ago. Lots of load break elbows all over the place. My job at the time did not involve any drilling. The only "tool" I brought with me into the vault was my camera. But I will have to arrange for an MV electrician (employed by the owner already) to pull a mandrell (spelling?) through a spare conduit, to prove it is available for me to use to bring another MV cable into the vault.

This type of work has its dangers, as does everything we do. There are special considerations for MV work, and a person working even in the vicinity of live MV cables needs to have special training and needs to follow special procedures.

 

[wawireguy]

Thanks Charlie. We may very well have the vault denergized before we begin working in it but like most places I've worked safety seems to be a after thought so I'm condsidering the different scenarios.

 

[quogueelectric]

Thanks Charlie. We may very well have the vault denergized before we begin working in it but like most places I've worked safety seems to be a after thought so I'm condsidering the different scenarios.

one of my first jobs I was sent to a 24 kv manhole job working with asbestos wrapped energized wires. As I was being fitted with ppe I let the foreman know this was my firs week in the trade. I cant print the rest.

 

[zog]

Thanks Charlie. We may very well have the vault denergized before we begin working in it but like most places I've worked safety seems to be a after thought so I'm condsidering the different scenarios.

Just to be clear, I didnt say you need to de-energize the vault, depending on the senario that may not be possible (Feasable), I have no idea what is involved. But you do need to get some MV guys involved. Locating the cables, arc supression blankets, and proper work procedures can allow you to do this job safely if you know what you are doing.

 

[jrannis]

Is it safe to be in a vault with 13.2K volts if you are not doing any work on the live system? The work will consist of core drilling and pulling conductors into the vault.

I'm not familiar with the type of connections that are made in this vault. I've heard them called load breaks. They are installed in rails on the wall. Almost looks like plugs into unistrut.

I'm concerned that there isn't anyone on this job that is qualified to assess the hazards and that there is no plan for working safely in this environment.

Is it possible for you to get some pics for us?

 

[iwire]

Pics from Chris

Pictures for John

 

[wawireguy]

Saw some of Zog's posts at Arcflash forum. Interesting information. Pretty much what I'm seeing is as unqualified personel we shouldn't be in the vault at all if it's live. Also what I'm seeing is that if you maintain the prohibited aproach boundary distance you probably won't get killed. The dielectric value of air should prevent you from getting electrocuted. I've got plans in the works to start working for a "group" thats more safety conscious soon but don't want to get killed in the mean time trying to make ends meet.

I don't "believe" there is any exposed live parts in this vault.

 

[wawireguy]

We may not even consider doing any work in it live either. Definetly not doing terminations. I just know the crew I'm working with and have seen them hop down in it a few times to make measurements so am just thinking ahead.