Do I need to upgrade to 200 amps?

Old 04-09-07, 06:41 AM
Thread Starter
Join Date: Apr 2007
Posts: 5
Upvotes: 0
Received 0 Upvotes on 0 Posts
Do I need to upgrade to 200 amps?

I have had 2 professional electricians to my house that I recently bought and one said I needed to upgrade to 200 amps and the other said my existing 100 amp service is enough.

House is 3600 sq feet built in 1969. 5 bedrooms 3 full baths 2 half baths.

House has Central Air and the only appliance that is electric is the double oven. Everything else including the heat is gas.

I want to add a ceiling fan to each bedroom and recessed lighting to the family room.

I noticed that two of my breakers are split/doubled up with the (2) 15 breakers. Nothing is really labeled but when I was doing some minor electrical work I noticed that one of these smaller 15 breakers controls 3 bedrooms and one of the full bathrooms. Seems that it is too much for one breaker?

My uneducated guess and gut tells me I need to upgrade, but I since 2 professionals differed I am not really sure.

Any thoughts or advice?
Old 04-09-07, 07:05 AM
Join Date: Sep 2003
Location: Central New York State
Posts: 13,246
Upvotes: 0
Received 0 Upvotes on 0 Posts
You are talking about two different things that have little to do with each other.

100 amps and 200 amps refers to the incoming power into the house and to the size of the main panel. You must have a 100 amp main panel. That means that the maximum power that you can supply your house with at any given moment is 100 amps at 240 volts. The wires that feed the panel are probably sized for 100 amps, although they could be sized for 200 amps.

The proper way to decide what service you need is to perform a load calculation. A load calculation is based on the size of the house, and then factors in whether you have gas or electric for cooking, heating, water heating, clothes drying, and air conditioning. A load calculation is not difficult, but it is not trivial either. Google the term "load calculation" and you will get plenty of information on the subject.

Even if a load calculation determined you need 200 amps, you have no requirement to change anything. This applies even if you split existing circuits into multiple circuits or make other changes. However, if your panel is full and you need a new panel, or you want to replace your panel for other reasons, it might be wise to upgrade to 200 amps.

As for your breakers not being labeled, sadly that is most often the case. However, you need to remedy this. Take the time some weekend to completely and thoroughly determine what is on each and very breaker. You need to know without any questions what breaker controls each and every receptacle, light and appliance in your house. Make a chart that is posted at the panel. Forget the small chart they provide, itís usually too small to list everything. This is a task you should have performed shortly after you moved in. The information will be invaluable in certain problem situations, but more importantly it could save your life some day.

Are you having troubles with a circuit breaker tripping on the bathroom/bedroom circuit? If so, then you need to address that problem. Addressing the problem might be as simple as not warming up the iron while vacuuming using a hair dryer. However, if the breaker doesn't trip and you aren't overloading the circuit then you have no problem and you donít need to address the issue.
Old 04-09-07, 07:20 AM
Join Date: Dec 2005
Location: USA
Posts: 2,926
Upvotes: 0
Received 1 Upvote on 1 Post
I think both electricians are correct. The difference is that one is looking at your present needs and the other is looking at possible future needs.
You mention an oven as your only electrical appliance. Do you have a wall mounted uwave, dishwasher, disposer, washing machine/dryer, computers, big screen TV's home entertainment systems?
Homes today have much higher electrical demands than they did 40 years ago when your electrical system was designed. If your load calculations indicate that you are anywhere near the limits of what your current system can provide, I suggest upgrading.
Old 04-09-07, 07:24 AM
Thread Starter
Join Date: Apr 2007
Posts: 5
Upvotes: 0
Received 0 Upvotes on 0 Posts
Re: Appliances

Thanks...I do have other appliances like you said (dishwasher, disposal, sump pump, TV, garage openers, ). The dryer, stove, and heat are gas.

Are there any rough estimating I recently bought this house and do not have all the manuals to know for sure how much current these appliances demand.
Old 04-09-07, 07:55 AM
Join Date: Sep 2000
Location: United States
Posts: 17,733
Upvotes: 0
Received 1 Upvote on 1 Post
If it ain't broke, don't fix it.

What problem are you trying to solve? If you don't have a problem, then you probably don't need to upgrade.

We can perform the demand load calculation for you. My guess is that it would suggest an upgrade. But before we go there, tell us what problem you have that you're trying to solve. Adding two ceiling fans and some recessed lighting is really a trivial change, unlikely to be the straw that breaks the camel's back.
Old 04-09-07, 09:34 AM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 9,785
Upvotes: 0
Received 45 Upvotes on 43 Posts
A 100A service "feels" underpowered for a 3600 sq ft, 5 bed, 5 bath house; however if you don't have main breaker tripping or overheating problems I doubt you _need_ an upgrade. A few can lights and ceiling fans is not sufficient load to require an immediate service upgrade, but it's something you may want to consider as ongoing home maintenance and updating.

If the demand load calculation shows you are okay with 100A, and if your main panel is full and cramped, which it sounds like it is, you could upgrade the panel to a 200A 40 space panel and leave the 100A incoming service as-is. This would provide you with plenty of breaker slots and would allow an upgrade to 200A in the future if you ever wanted a spa, for example. The panel replacement is typically about half the cost of a full upgrade.

You may be able to avoid replacement of the main panel entirely through appropriate use of tandem breakers. It's possible however, that your main panel does not support tandem breakers so increasing to a larger panel is the only way to add circuits; the electrician who recommended upgrade may have noticed this.
Old 04-09-07, 05:06 PM
Banned. Rule And/Or Policy Violation
Join Date: Feb 2006
Location: North of Boston, MA.
Posts: 1,967
Upvotes: 0
Received 0 Upvotes on 0 Posts

Ask 3 electricians (or three other trades people) and you may get 3 answers.
Nothing wrong with that, too many reasons to explain.

3600 sq' house, 100A on the face seems small.

More room? add a sub panel, (more ckts). Do a load calc.

Your highest demand items are gas, not a worry.
As suggested, address the problem at hand. A few lights will not cause chaos.

However, If you want to add central air, a pool, whirlpool and the like. This may be the time to go to 200A.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: