480V Panelboard
- Thread starter arito
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ryan_618
Senior Member
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- Salt Lake City, Utah
Re: 480V Panelboard
Your profile says that you are a consultant, and yet you are asking about the fundamentals of circuitry. May I ask, what exactly do you consult?
Your profile says that you are a consultant, and yet you are asking about the fundamentals of circuitry. May I ask, what exactly do you consult?
- Location
- Massachusetts
Re: 480V Panelboard
Where did the 30% come from?
gvmv
Member
- Location
- Travelling Electrician
Re: 480V Panelboard
Now I am only a 1st Year Apprentice but alas I do spend a quite a bit of time in my code book wanting to be a good Electrician. Art. 215 on Feeders
215.2 (A)(1) Can't list what acutally says because of copyright.
But wouldn't it fall under this in code? Which basicaly says size for load (as calculated in 220 on branch circuits) if non-continuals and 125% if continuous.
Thanks just trying to figure out myself where +30% came from.
Now I am only a 1st Year Apprentice but alas I do spend a quite a bit of time in my code book wanting to be a good Electrician. Art. 215 on Feeders
215.2 (A)(1) Can't list what acutally says because of copyright.
But wouldn't it fall under this in code? Which basicaly says size for load (as calculated in 220 on branch circuits) if non-continuals and 125% if continuous.
Thanks just trying to figure out myself where +30% came from.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: 480V Panelboard
This section of the Mike Holt NEC Frum relates to code. The code answer is that the feeder is sized for the load. gvmv has the correct code reference. The feeder must be sized for 100% of the non-continuous load plus 125% of the continuous load. The rating of the panelboard does not enter into that equation.
Now let us digress: set the NEC book aside, and enter the design world. I would recommend sizing any panel?s feeder to handle the rating of the panel. If you have a 225 amp panel, then give it 225 amp?s worth of feeder. Note that you don?t have to size the feeder for 125% of the panel rating. The design process should not permit the calculated load (for that panel) to go beyond 100% of the non-continuous load plus 125% of the continuous load. All this is, of course, a design consideration. It is intended to support future expansion. More to the point, it goes beyond code requirements, in order to make the customer happy.
This section of the Mike Holt NEC Frum relates to code. The code answer is that the feeder is sized for the load. gvmv has the correct code reference. The feeder must be sized for 100% of the non-continuous load plus 125% of the continuous load. The rating of the panelboard does not enter into that equation.
Now let us digress: set the NEC book aside, and enter the design world. I would recommend sizing any panel?s feeder to handle the rating of the panel. If you have a 225 amp panel, then give it 225 amp?s worth of feeder. Note that you don?t have to size the feeder for 125% of the panel rating. The design process should not permit the calculated load (for that panel) to go beyond 100% of the non-continuous load plus 125% of the continuous load. All this is, of course, a design consideration. It is intended to support future expansion. More to the point, it goes beyond code requirements, in order to make the customer happy.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: 480V Panelboard
Amen charlie. If I see a 200 amp panelboard, I would expect its good for 200 amps. the service entrance conductors are only sized to the calculated load. You can round up to the next standard size OCPD. If my load is calculated at 175.6 amps, I can round up to 200 amp disconnect as long as the conductors are sized for 175.6 amperes.
Amen charlie. If I see a 200 amp panelboard, I would expect its good for 200 amps. the service entrance conductors are only sized to the calculated load. You can round up to the next standard size OCPD. If my load is calculated at 175.6 amps, I can round up to 200 amp disconnect as long as the conductors are sized for 175.6 amperes.
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
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- EC
Re: 480V Panelboard
...215.2 (A)(1) Can't list what acutally says because of copyright.
Huh? Anybody ever had the NFPA threaten them with copyright infringement because they quoted an article here? This is a code forum, and it would be kind of tough to discuss the NEC without verbatim quotes and I think the NFPA realizes that.
...215.2 (A)(1) Can't list what acutally says because of copyright.
Huh? Anybody ever had the NFPA threaten them with copyright infringement because they quoted an article here? This is a code forum, and it would be kind of tough to discuss the NEC without verbatim quotes and I think the NFPA realizes that.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: 480V Panelboard
There is fair use of copyrighted material, its ok to quote limited amounts. If there was a long quote from the NEC I would ask it be edited down. Besides, we should all have the NEC.
There is fair use of copyrighted material, its ok to quote limited amounts. If there was a long quote from the NEC I would ask it be edited down. Besides, we should all have the NEC.
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