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View Full Version : How to count capacity of electrical service panel?


Narataru
Dec 1, 2009, 03:22 PM
The electrical service panel in my house is physically full. It is a 125amp panel.
I'd like to know if additional amperage can be added. How do I count the capacity of the panel?

Thanks:confused:

Tev
Dec 1, 2009, 06:23 PM
You have an electrician do a load calculation. There really isn't a better way.


There are online utilities for load calculations but I have never used them and therefore cannot recommend them.

KISS
Dec 1, 2009, 07:59 PM
If you really feel up to it, read the NEC online and follow the instructons in the code. How to read online is in the stiky in the Electrical & LIghting link on the top left.

Adding the breakers up doesn't count.

There are twin breakers available for some panels and for some locations in some panels that allow multiple circuits in a single space and there is the use of subpanels.

A Load calculation will give you the size panel that you need.

donf
Dec 2, 2009, 07:43 AM
Narataru,

Why did you resubmit this question. I answered it yesterday.

Narataru
Dec 2, 2009, 01:49 PM
Narataru,

Why did you resubmit this question. I answered it yesterday.

Because I'm still looking for answers. I didn't agree with yours, it wasn't enough for me. I might be lucky and find an electrician in this site to answer my question.

tkrussell
Dec 2, 2009, 03:22 PM
What is wrong with this answer?


You have an electrician do a load calculation. There really isn't a better way.

If you have done a search for other previous questions such as yours in this forum, you would have found that the details needed to do a load calculation are the total square footage of livable space of the home, and a list of all major electrical appliances, to include the voltage, wattage or amp draw, size and type of heat and air conditioning.

With that I can do the calcs, but you should not use my advice, as without reviewing the home and appliances myself, I take no responsibility for accuracy.


Don't bother trying to do the calcs on your ow by reviewing the NEC, as suggested. Load calcs are derived from Article 220, and must be done by a trained qualified person. The NEC is not written for laypeople.

Washington1
Dec 2, 2009, 06:10 PM
The NEC is not written for laypeople. I agree, heck I have a hard enough time trying to understand it!!

tkrussell
Dec 2, 2009, 06:17 PM
Amen!


I agree, heck I have a hard enough time trying to understand it!!!

Where you been?

Really miss your perspective on many questions here.

Hope all is well.

mcad
Dec 2, 2009, 07:46 PM
Narataru,

I am a new member on this site, but as an electrician that reads a lot of the posts on here, and the replies by tk, donf, and k.i.s.s. I assure you that any advice they give you is more than valid and coming from more than qualified people. When someone on here recommends someone to hire an electrician it is because some things just are not as easy as a couple of paragraph explanation. And not only is safety a major issue, but expense too. Trust me that if you did the calculation wrong and bought and attempted to use the material (cut wire that is non returnable, etc.) this job would cost A lot more than it would to have a qualified electrician do it for you.

Washington1
Dec 3, 2009, 08:46 AM
Amen!



Where ya been?

Really miss your perspective on many questions here.

Hope all is well.

I've been around!! Things are slow, so I've been spending more time online. Much stress from lack of business... etc... etc!!

Happy to see you are still around---providing outstanding information!!

Narataru
Dec 3, 2009, 04:40 PM
I agree, Stanfortyman, I'm clueless how this site works, probably after 2,000 posts I'll understand why this post was deleted yesterday and is back again today.
You as an electrician didn't help at all with your comments.
My comments are... very dissatisfied!!

KISS
Dec 3, 2009, 06:19 PM
Narataru:
Your posts may have been involved in a unintentional mistake made in moderating the boards which was noticed and fixed by another moderator. Since I wasn't involved, I can't be certain it was your post(s) or thread(s) were involved.

Unfortunately, you didn't get a concise answer up front which I think is: The instructions are in the NEC which you can read online for free. It's suggested that a licensed electrician do the calcs for you because the calculations are not straightforward and easy to understand and the members of AMHD or AMHD cannot be held accountable.

donf
Dec 3, 2009, 06:20 PM
Narataru,

I'm not a mean spirited person in any way but I feel obligated to point out some things to you.

First, you have been given the correct answer, several times in fact. The problem is that you do not like the answer. That is in no way our fault!

Second, how many responses have you received from folks on this thread. Do you for a minute think that they do not care. If that was the case, they would simply have not answered your question.

What you are asking is not trivial and cannot be answered by just reading a manual. Just like you cannot become a Master Electrician just by taking the test. You are required to have many hours of on the job experience to get that license.

For example, TK responded to a post by you concerning the Main Service Panel and the Sub Panel.

Do you know why the sub-panel (at the house) would have to be modified and how to make the modification or replace the panel if necessary. Do you understand the need and reason for the grounding rod at the house and the grounding rods at the main service. Do you know how to size and calculate the voltage drop from the main service panel to the house sub-panel.

Believe it or not, all this was covered in TK's post. How is he to know you have a complete understanding of what was relayed to you?

Frankly, we are forced to "Infer" from questions a level of the posters abilities. In your case, to a person on this forum we have all said that you should seek professional help. We are not trying to be insulting. We are trying to be practical and provide you with the correct and safest way to get the job done.

KISS
Dec 3, 2009, 06:27 PM
Don:
You did a nice job.

Narataru:
I'd also like to point out that there are websites that will not help anyone with HVAC thermostat wiring issues, for example.

Narataru
Dec 4, 2009, 08:49 AM
I want to thank all for your answers, they show very clear your interest in helping me the most accurately possibly. I understand that I'm a bit frustrated when I don't understand a topic because I love to do renovations myself. I will look for advise from an expertise electrician who will check my case in particular.
I apologize if I was a little bit mean, I was expressing my free opinion in this forum and I didn't realized that if I disagree with someone I need a better reason, not just that I didn't like the answer.
Thanks to all again.

donf
Dec 4, 2009, 09:13 AM
Narataru,

I understand, I enjoy doing the work myself.

May I offer this suggestion. Ask the licensed electrician that does the load study how he is deriving the values for the study.

For that matter, if you go have an electrician do the actual work, ask if you can do the scut work in exchange for a reduced price and the education he can pass along.

With luck, he will agree.

Good luck

KISS
Dec 4, 2009, 06:46 PM
I took a look at your other questions for fun and most appear to be straightforward. The water meter one didn't show the direction of the water which is an important concept.

Your refrigerator question didn't get answered. https://www.askmehelpdesk.com/appliances/new-fridge-doesnt-work-409858.html. We missed it.
What ever happened?

My response would have been something like. Let it stand verticle for 24 hrs before plugging it in. The oil can shift and cause issues with the compressor. Shipping on it's side would depend on what side and it there were exposed outside coils.

Again, though it was unclear what didn't work. The light. The compressor would not turn on. Maybe confusion as to what is cooler. Waiting for it to get cold.

The Appliance area, I'll admit gets neglected a bit, because it's difficult because usually not enough info is supplied. Questions like "My Kenmore series 80 doesn't heat". And you have to infer it's a dryer. You don't know if it's electric or gas. You don't know what was tried. You don't have a model number. Although I'm not considered an expert there, I did put a sticky there for troubleshooting gas dryers and I think it's cut down the questions on gas driers. The powers that be won't let me have expert status there. So be it.

Remember, for us, some questions are easy, some are harder. Some just require too much effort.

We don't know the skill levels of the poster or even if the own a multimeter or even know how to use it. The way you present yourself, determines a lot how we answer questions. Sometimes we have to guess. We'll guess if it doesn't require too much effort.

I believe, capacity questions have come up in the past and we just said, "Have a load calculation performed" and that was it. While tk offered to do it, he may happen to have an expensive piece of software that allows him to do it easily.

We also learn from each other, but we better be prepared to be able to back statements up

Similarly in the HVAC forum, there are issues about AC and heater sizing. We tend to just say have a Manual D (Duct) or Manual J (Heat and AC load) calculations performed.
While I have done both and understand both it's just not easy to do. It might take 15 minutes when one has a $2000 software program and is able to do a 10 min walkthru of the property and knows all of the factors necessary for the locality.

I like what you said in post #15.

AT some point you have to draw the line in what you are willing to do and even what tools you would need to purchase for the job.

My mom had a broken stabilizer bar on her car $800-$850 estimate. Could I have done the job? I could do everything but a 4 wheel alignment for $75 and about $275 in parts.

We went to plan B. We didn''t tell the dealer what was wrong and she took it in for an oil change and had a coupon for a $300 inspection that included a suspension inspection and we also wanted the tires rotated.

Well, they didn't find the problem. I found it when I changed a tire when the low-air pressure light cam on. THEY were supposed to do an INSPECTION and they had the tires off.
Why couldn't they find it?

They told my mom the car would not be driveable with a broken stabilizer bar and REFUSED to take a look at it before she left.

Armed with pictures and a visit to the service manager who was angry, BTW and he offered to do the job for about $430 with shuttle service.

For yet another service which I found the problem. I blown valve cover gasket. The engine needed pulling. I could do it except for that minor point. Since I knew what was required, I checked a few things when they were done. They overfilled the oil by about 1.5" on the dipstick.

I think we learn here, we help here, we become better people here. Public relations is not my strong point, but I'm getting better because of this site. I'm also always learning here too.