110.27 Guarding of Live Parts

[mshields]

What is the practical intent of 110.27(4) which indicates that one can guard against contact with live parts by elevating the equipment a minimum of 8.5 feet for up to 600V.

What equipment might one find, not enclosed but instead relying on this rule to protect against accidental contact?

 

[fmtjfw]

What is the practical intent of 110.27(4) which indicates that one can guard against contact with live parts by elevating the equipment a minimum of 8.5 feet for up to 600V.

What equipment might one find, not enclosed but instead relying on this rule to protect against accidental contact?

Walk outside, stare at the secondary on any power pole.

Look at the secondary on a mast down to a meter.

Go look at any trolley line in Boston.

 

[don_resqcapt19]

Old crane rail bus comes to mind...it was all just bare copper, not covered like it is now. Other older installations used bare open bus bar for power distribution, but that was normally in a locked room, and did not need to use the height part of the rule.

Not sure you will find many new installations that have exposed live parts that are guarded only by height, other than overhead lines, but overhead lines are covered by other rules and the minimum height is higher than 8'.

 

[mshields]

thanks and while I'm at it

thanks and while I'm at it

is there a quick way to thank people for their input, sort of give a thumbs up without posting a reply. Something akin to the "like" function in Facebook.