Fence in Electical Vault

[Electrobe]

Looking at putting a cyclone fence around a 15KV vacuum switch in an electrical vault. What distance does this fence need to be from the exposed conductors?

6Ft working space as per 110.34 or 10FT as per 110.31?

Thanks

 

[Inspectorcliff]

110.31 fences and screens above 600 volts

110.31 fences and screens above 600 volts

Looking at putting a cyclone fence around a 15KV vacuum switch in an electrical vault. What distance does this fence need to be from the exposed conductors?

6Ft working space as per 110.34 or 10FT as per 110.31?

Thanks

Check out 110.31 I think it well give you the information you need.

 

[Electrobe]

I am not sure but I think table 110-31 is only used for outdoor installations??

This fence would remained locked and only be accessable when the switch was deenergized. Wouldn't the fence be simular to a wall (other than long objects could go through holes and contact energized parts)?

Seems like a safe distance would be outside the flash protection boundry?

Thanks

 

[Pierre C Belarge]

I am not sure but I think table 110-31 is only used for outdoor installations??

This fence would remained locked and only be accessable when the switch was deenergized. Wouldn't the fence be simular to a wall (other than long objects could go through holes and contact energized parts)?

Seems like a safe distance would be outside the flash protection boundry?

Thanks

"110.31 Enclosure for Electrical Installations.
Electrical installations in a vault, room, or closet or in an area surrounded by a wall, screen, or fence..."

Typically, I believe you can find vaults, rooms and closets inside of a building.

 

[Electrobe]

NEC 110.31 (second paragraph)
For installations other than equipment as described in 110.31(D), a wall, screen, or fence shall be used to enclose an outdoor electrical installation to deter access by persons who are not qualified. A fence fence shall not be less than 2.1 m (7ft) in height or a combination of 1.8m (6ft) or more of fence fabric and a 300mm (1ft) or more extension utilizing three or more strands of barbed wire or equivalent. The distance from the fence to live parts shall be not less than given in table 110.31.

Is table 110.31 for all fences or just outside fences?

Does a fence that is installed within a vault used to retrict access to live parts need to meet the requirements of this table? In my example, the vault can only be entered by qualified persons and the fence gate could only be entered when power was off to the live parts.