ECN Forum Forums Code Related Discussion NEC & other Code issues sizing service and service feeder

Greg, there is no way to get prior electric bills, since this building has been vacant for a long time. I don't even know who the previous owner was. The one who is having the work done, has purchased the building, and is having the wiring done, so he can move his existing business from another location into this one. You said my calculations was wrong. Would you care to educate me a little more? If so, I would appreciate it. If not that's alright too. Thanks Steve

Hi,
First - tell us WHY you want to calculate the existing load?

Second - what will you do with the information?

I did not see any mention of these articles in any of your post..

Start by READING the following articles:

220 Part II
220.3(B)(1) thru (B)(11)
411;215.2(A)(1);230.42(A)(1)
220.4(b); 215.2(A)(1);230.42(A)(1)
220.3(B)(6);215.2(A)(1);230.42(A)(1)
220.3(B)(9); Table 220.13
220.3(B)(9);215.2(A)(1);230.42(A)(1)
220.12(B)
220.3(B)(9); Table 220.13
220.3(B)(8)(1);(2)
215.2(A)(1);230.42(A)(1)
215.2(A)(1);230.42(A)(1)
440.34
440.34;215.2(A)(1);230.42(A)(1)
220.14;430.24
220.21
220.14;430.24
220.35
220.35 Ex.
220.22;310.15(B)(4)(c) To Table 310.16
90.8
------------------------------------------

Finally, find STALLCUPS ELECTRICAL DESIGN BOOK and BUY it! There is hardly ANY better reference out there that I know of. I use it EVERYDAY.

I will chew on your list and get back to you.

Thats about the best I can do right now.

DO NOT GET IN A RUSH!

-regards

greg

[This message has been edited by mustangelectric (edited 03-17-2005).]

Thank you Tom for your reply.
In past conversation with the power company, I don't think they will provide the 120/240 delta. As far as the conductors in the previous 277/480 service, they are 3/0 parralled. I intended on installing a 400 amp. main breaker panel back in this location. We are trying to get as many of the motor loads as possible on the 277/480 volt service. Right now not counting the motors I described in my original post, I will have probably (14) 3 phase motors coming off of the 277/480 volt service if possible. That will be 42 circuit panel. (Just now realized that.) I have calculated the estimated amps. as 170.8 amps. I know that would give me ample room to add the other ones probably (as far as amps that is) , but then I now realize I will have to set a sub panel coming off of this one, for future expansion, but some of the motors are not convertible according to the nameplate, and also they are already piped into the 120/208 panel. The 277/480 panel will be a long way off from the locations of these machines also. The other machines I am planning on taking to the 277/480 panel will not be that far from it. The machines that I do plan to tell him that we will have to convert to 460, unless we change the existing 120/208 200 amp. service, may or may not even be able to be converted. Most of the machines are not present in the building at this time, and I am having to go back and forth to get the information I need. When most of the necessary wiring is done, he is planning to move his machines at that time, and do the rest of the "hook ups" etc. He cannot afford to shut down his existing business now to move the machines into the new plant. Hope this helps explain things a little more.. Thanks again for your help. Steve

[This message has been edited by sparkync (edited 03-17-2005).]

Hi sparkync,

It is not a good idea to apply 220.?? demand factors in an industrial environment. As most business owners want to see their business go and will do anything to ensure it's growth, there will be a time when all machines will be operating at the same time.

Also, 180VA per receptacle at 100% is okay for normal use. However, you should also take into account if they have any drill presses or bench grinders, etc. plugged into a receptacle and add those device's load at 100% to the receptacle load.

Additionally, is the general lighting load a 2VA per sq.ft. a reality in this shop? Are you going to add additional lighting that 2VA per sq.ft did not cover?

If the building has a office then the use of NEC 220.?? is good, other than that, I'd stick to 100% load for the working side of the building.

[This message has been edited by DiverDan (edited 03-17-2005).]

Thank you also Dan for your input,
The 2 watts/sq. ft. might not come into play with all his facility, being that for now, a large portion may be considered storage, which would only calculate at 1/4 wt./sq. ft., but I went ahead and figured it at 2, because of the very fact you said. In a shop like this, he will be wide open to put out orders etc., and I'm sure he'll be using it also for production machinery. My general calculations were that I would figure everything at 100%. I was wanting to make sure before I broke the bad news to him, that I was figuring right. My main question I guess was that according to the calculations I done above, if correct, there is absolutely no more room for machine loads on the existing 120/208 200 amp. service with my calculations being in the minimum of 207 amps. And yes, he already has floor fans setting around, a welder, and who knows what else might be there, once he moves in. That's my next decision before I can do more work, is to break the bad news to him, that the existing service will have to be changed to at least 400 amp., to take care of all the machinery he is expecting to use. I just needed some other verification that I was right.... Thanks again for the input.. Steve

Hi,

Dan- You said: "It is not a good idea to apply 220.?? demand factors in an industrial environment."

What?

There is NO way you can correctly calculate the SE WITHOUT applying article 220 and remain within the NEC. (PERIOD)

No offense dan but what on earth gives you that idea?

do you see the list of articles I posted above? each one of those covers INDUSTRIAL applications..you can ignore them if you want to..

if you do your calculation wont be worth the paper you wrote it on.

I will let you guys handle this! Im out!

-regards

Greg



[This message has been edited by mustangelectric (edited 03-17-2005).]

You're right Greg, its late and I'm also tired...so I won't bother with your overly simplified response either. By the way. a Demand Factor is a derating factor and the working side of an industrial environment should not have any applied deman factors (derating). PERIOD! If you think it does then you have never been involved with any format of large or small manufacturing. PERIOD!

I guess I should say something else about NEC 220.??. As you all know, these are application specific "general" branch circuit and service sizing methods, kind of like "black box" engineering. As such, most EE's and Design Engineers do not and will never use them as a valid means of circuit or service sizing. They only use specific device characteristics inconjuction with continuous - non-continuous load factors to size the circuit and service for final presentation. It was with alot of controversy that we included them in Volts. But since many electricans requested their inclusion...we included them.

Greg I got here late but can you explain what you mean by this?


There is no requirement in the NEC to size a service for future expansion.



It is right in article 220




What part of the code says that?

120 x 20 = 2400 watts.

We can load a 20 amp circuit to 20 amps (2400 watts) if it is non-continuous.

If it is a continuous load (on for more than 3 hours at a time) we can only load to 80%.

120 x 20 = 2400 x .8 = 1920 watts.

One last thing Greg, using all capitols is considered shouting and rude.

You are coming on very strong in this thread when IMO you should be asking more questions.

If you are going to say something is 'code' get out the book and tell us the code section you are referring to. That 'laundry' list of code sections you posted does not help.

Thanks, Bob




[This message has been edited by iwire (edited 03-18-2005).]

Hi,
Like I said there is NO WAY to properly calculate the LOADS in a INDUSTRIAL environment without using the following articles:

220 Part II
220.3(B)(1) thru (B)(11)
411;215.2(A)(1);230.42(A)(1)
220.4(b); 215.2(A)(1);230.42(A)(1)
220.3(B)(6);215.2(A)(1);230.42(A)(1)
220.3(B)(9); Table 220.13
220.3(B)(9);215.2(A)(1);230.42(A)(1)
220.12(B)
220.3(B)(9); Table 220.13
220.3(B)(8)(1);(2)
215.2(A)(1);230.42(A)(1)
215.2(A)(1);230.42(A)(1)
440.34
440.34;215.2(A)(1);230.42(A)(1)
220.14;430.24
220.21
220.14;430.24
220.35
220.35 Ex.
220.22;310.15(B)(4)(c) To Table 310.16
90.8
------------------------------------------

that said, anybody that doesnt agree is certainly entitled to disagree. Myself I will stick with Stallcup before I listen to any of the advice that has been posted in this thread.

just for the sake of arguing:

someone said: "By the way. a Demand Factor is a derating factor and the working side of an industrial environment should not have any applied deman factors (derating). PERIOD! If you think it does then you have never been involved with any format of large or small manufacturing. PERIOD!"

you also said: "As you all know, these are application specific "general" branch circuit and service sizing methods, kind of like "black box" engineering. As such, most EE's and Design Engineers do not and will never use them as a valid means of circuit or service sizing."

my response to that? You are a dangerous person and have NO business even being involved with the electrical trade. your comments are ridiculous and nothing more than an attack, this was a discussion, now it is nothing more than a pissing match with someone who OBVIOUSLY doesnt have a clue so I will not even respond to anymore of your comments.--

ANYONE who says that providing room for future expansion IS NOT part of the code is obviously not very knowledgeable in regards to the code and doing electrical work...you are the kind of guy who will go out and installa 32 circuit panel and fill it up and leave no spaces for anything in the future..there are PLENTY of sections in the code that require this...I suggest you either take a course or start all over and go back to sqaure one..i would love to see some of your work..it probably would wind up over there at the "whats wrong with this picture" pages..

if you want to load a 20A circuit to 2400VA go right ahead..once again there are several other articles in the code that would not agree with that...myself, I call it riduclous and DANGEROUS.

someone also said: "One last thing Greg, using all capitols is considered shouting and rude."

my response: that is YOUR opinion...the truth? if I used ALL CAPITALS LETTERS LIKE THIS THEN I AM SHOUTING AT YOU! GET REAL! I was simply EMPHASIZING AND STRESSING THE WORD! your kinda touchy aint ya? have a bad day or what?

someone said: "You are coming on very strong in this thread when IMO you should be asking more questions." I do ask questions...when I want to know the answer to something I dont already know. but thanks for being so friendly!

another ridiculos statement: "That 'laundry' list of code sections you posted does not help."

well i guess James Stallcup is an idiot too and knows nothing about the code?

becasue that laundry list of articles that does not help came from JAMES STALLCUPS "DESIGNING ELECTRICAL SYSTEMS" LOOK IT UP! LOOK at Stallcups electrical design book and go to "SIZING INDUSTRIAL LOADS" after you do that go tell James that he wasted his time printing millions of books and spending millions of dollars putting ou that USELESS information! MAN! some poeple!

I will stick with stallcup.

so now that I have responded to all of these ridiculos comments and attacks, I will bow out of this thread and let the "EXPERTS' have their way.

My sincere apologies if anyone got offended, sometimes the written word doesnt carry the same meaning as the spoken word so forgive me if anyone got upset.

TAKE TWO AND THINK IT THROUGH!

-regards


Greg