code clearance

[john37]

I have a question regarding clearances. I have a situation where there is a 1200A main disconnect switch and then an ATS across the switch. Does it require the 3 foot clearance or 4 foot clearance? Per Article 110.26(A)(1) would this meet the condition 3 where exposed live parts on both sides fo the working space requires 4 foot clearance? Thanks...

 

[charlie b]

I consider two devices facing each other as a Condition 3 situation. So, yes, the four foot clearance requirement applies. I presume that you are talking about a 277/480 volt system. If the equipment is 120/208, you only need 3 feet, even in Condition 3.

 

[john37]

Thanks Charlie. Yes it is 277/480V. I thought it met condition 3 as well but just wanted to make sure. I asked the contractor to have the inspector take a look because the clearance right now is something around 44" I believe.

 

[spsnyder]

It may not help in this situation since you have 44", but the prefered unit is metric, as was pointed out to me on this forum... The table gives 1.2 meters as the required distance, which is 47.2".

"90.9 Units of Measurement
(A) Measurement System of Preference For the purpose of this Code, metric units of measurement are in accordance with the modernized metric system known as the International System of Units (SI)."