NEC 220.87

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codequestion

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I am trying to figure out existing load for 3000 amps 120/208V switchgear but i am not sure if it has overload protection. I was wondering if NEC 2014 220.87 I can use utility electric bill load for 12 months bill and get max peak demand kwh from that to determine existing load or do i need max kva?

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codequestion said:
I am not sure regarding the third condition service overload protectionand overcirrent protection for feeder I have main breaker in switchboard but I think thats overcurrent protection. I have feeder breakers from switchboard.

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codequestion said:
I am trying to figure out existing load for 3000 amps 120/208V switchgear but i am not sure if it has overload protection. I was wondering if NEC 2014 220.87 I can use utility electric bill load for 12 months bill and get max peak demand kwh from that to determine existing load or do i need max kva?

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If POCO has metering that records demand data (most usually will on a service of this kind of capacity, in fact they do use it for applying demand charges) then you can use that demand data to come up with maximum demand.

What you can't do that some want to try at times is use total kWH and average that out to come up with demand. All total kWH tells you is what was used, but it could have mostly all been used in first 72 hours of billing period at a high demand then sat nearly idle for the rest of the period.
 
electrofelon said:
I dont understand what the purpose of condition #3 in 220.87 is. Are they trying to say that I cant have a service that utilizes any of the exceptions in 230.90?
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I don't think so, "and the service has overload protection in accordance with 230.90." As worded wouldn't exceptions be included?
 
electrofelon said:
Yes I would also think the exceptions would be included. I just don't understand what they mean. Why wouldn't a service meet 230.90? If not done code compliantly I guess.
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Does seem somewhat redundant, one should expect it to be code compliant, if not how do you do anything with it without bringing it up to code?
 
kwired said:
Does seem somewhat redundant, one should expect it to be code compliant, if not how do you do anything with it without bringing it up to code?
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What does the third part mean anyways? You have overcurrent protrction from main do it says to main overlaod orotection? I a confused.

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codequestion said:
What does the third part mean anyways? You have overcurrent protrction from main do it says to main overlaod orotection? I a confused.

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It is addressing both services and feeders, but each has different locations in NEC for requirements. But it basically says (IMO as well as EF's) that overcurrent protection must be in accordance with code, which seems like a bit of a forehead slapping moment to have to mention that.:slaphead:
 
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