Why is 200 amps standard for residential panels?

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JoeNorm

Senior Member
Location
WA
The question is in the title. Doesn't 200 amps seem overkill for the majority of residences? Does anyone know the history behind this?
 

480sparky

Senior Member
Location
Iowegia
A 200a service costs less than $100 more than a 100-amp service.

Yeah, penny-pinching cookie-cutter homes probably opt for 100 or 150amps. But with such a small difference in price, it's silly to skimp on it.
 

drcampbell

Senior Member
Location
The Motor City, Michigan USA
Occupation
Registered Professional Engineer
In the midwest, where gas heat, cooking and water heating is the norm, 100 amps was probably overkill.

I suspect it has been a combination of being unable to predict the future, seeing 30-amp and 60-amp services phased out, the "bigger is better" mentality and a relatively-insignificant cost increment in the past. But with electric vehicles now highly foreseeable, a 200-amp minimum seems entirely reasonable. (and might even prove inadequate if we start looking at all-electric heating and two EVs)
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Under the TVA system, many homes are all electric and load calculations would often require a 150 amp.
200 is not that much more expensive and is readily available. (25% of the homes here have 400 amp)
 

JoeNorm

Senior Member
Location
WA
It's true that currently with "all electric" on the rise and EV's the 200 amp service is becoming more necessary. And sometimes more.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
FWIW or not......
We have a have a four-bedroom house upstairs, kitchen, dining room, lounge, etc. The DB is 63A. More than double that of a typical US residential.
Yes, we use just 230V single phase but then you have 120-0-120. The differences surprise me somewhat.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
My opinion is that a 200a service allows most installations to avoid having to do a load calc.

Plus, the reasoning is that the labor is the same (almost) and materials cost almost the same.

Actually, 200a service equipment may not cost any more for supply-and-demand reasons.
 

Coppersmith

Senior Member
Location
Tampa, FL, USA
Occupation
Electrical Contractor
IMHO, It's all for show to sell houses. "Our houses feature 200 amp electrical systems!"

You could also ask why all the very expensive homes have 400 amp systems. Same reason. 200 amps is for the middle class.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
As was mentioned, the 200A isn't much more than a 100A. But along with that, you get more panel space with (most) 200A panels. That's where most people find a problem when adding on, no space for more circuits with the smaller 30 space panels.
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
IMHO, you have to evaluate the size of the house you are installing the service in, especially if it's a service upgrade. If the house is a Cape Cod, on a postage sized piece of property and there are only 6 existing circuits, upgrading to a 200A service is over-kill. In a recent upgrade that I did there was an existing 100A/20 ckt. service that was packed with breakers including 4 tandems. There was excessive damage to to the house due to storm in August of 2020 and the entire kitchen had to be re-constructed. I upgraded to 150A/30 ckt. service because the house had a 40A electric range/oven, a 30A water heater and a 40A sub-panel. Upgrading to a 200A/40 ckt service would have been over-kill in this situation.

Wiring mega-mansions are a totally different story
 

domnic

Senior Member
Occupation
Electrical Contractor
A 200a service costs less than $100 more than a 100-amp service.

Yeah, penny-pinching cookie-cutter homes probably opt for 100 or 150amps. But with such a small difference in price, it's silly to skimp on it.
 

480sparky

Senior Member
Location
Iowegia
We're talking about the service. Not the difference between a 100a panel with 12 breakers and a 200a service with 40 breakers.

Just the service itself.
 
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