230.71(a)Max # of disconnects

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douglasjones

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I am having a discussion with fellow workers about this rule.I work at a plant in arkansas we have boards set up in different parts of the plant with disconnects on them.Some of them have quite a few on them and have been there for many years.Some of our machines don't pull many amps and some of them are to just isolate them so we don't have to shut the total machine down.The problem is 6 disconnects might only serve 50 amps on a 100 or 200 amp feed.Some boards have a main disconnect on them others have a disconnect at the closest distribution panel.The boss won't buy a 3 phase breaker panel.We don't have an outside authority that regulates how we install anything except us.It seems like alot of trouble to follow this rule.
 
230.71 a is for the main service disconnecting means for the plant. Maybe I am wrong but it sounds like your talking about various feeders in your plant. I believe the six switch rule is for the main service so as to not take more than six throws of the hand to shut it down. In the commercial and industrial trade lots of people will install six smaller distribution breakers in a large service and branch off to smaller panelboards to save money on a large main breaker. I am installing two 3000 amp services now and believe me I thought about doing the same. I believe this also applies to a transformer secondary.
 
teco said:
230.71 a is for the main service disconnecting means for the plant. Maybe I am wrong but it sounds like your talking about various feeders in your plant. I believe the six switch rule is for the main service so as to not take more than six throws of the hand to shut it down. In the commercial and industrial trade lots of people will install six smaller distribution breakers in a large service and branch off to smaller panelboards to save money on a large main breaker. I am installing two 3000 amp services now and believe me I thought about doing the same. I believe this also applies to a transformer secondary.
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A SERVICE is defined as the "conductors and equipment for delivering electrical energy from the service utility to the wiring system of the premises. served". We sometimes use service when we mean the service entrance
conductors and equipment. 230.71 allows 6 switches or breakers for each set of service entrance conductors. So Teco, you could have 6 breakers in each of the 3000 amps main panels that you are installing without a main breaker, assuming there is only one service.
 
Hi bob,
I need to refeed seven 400 amp bus ducts and two 300 amp roof top units and various other large loads from the new main switchgear location. The other service has even more to refeed. Both services are for one company. None of the company departments will give up the real estate to install other panels to feed from the main six breakers if I set it up that way. One new service is 120/208 and the other is 480/277 and this one is required to be G.F.I protected as I'm sure you know.
So after many meetings we decided to install the mains. Big money.
Thanx
Mark
 
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