200 amp services all electric houses

[Greg1707]

This week we replaced panels in two houses built in the 1970s. Both are all electric. One was a 1,100 square foot town house and the other was a 2800 square foot ranch house with basement. No pools or anything extra.

:? Both houses had 200 amp services.

Maybe one house was oversized and the other was undersized?

 

[peter d]

200 amps goes a long way, much further than most people are accustomed to thinking. Of course, the real answer depends on a load calculation, but keep in mind that the NEC is highly conservative and the actual load, even with electric heat, will be well under NEC calculations.

 

[jaggedben]

The difference in load calculation for that 1700 sq ft difference is 5100VA or only 21.25amps on a 240V service. So since you're most likely going to 200A if you need more than 125A, that 21A really doesn't mean much. The appliances matter to the load calculation a whole lot more than the square footage. Not to mention these days with fluorescent and LED lighting the 3VA per sq ft calc is probably a few times what's really needed.

I've done a bunch of load calculations for existing dwellings (220.83) and very few have needed more than 100A. I did one that had two ovens, a dryer and a car charger, and it came to 99A.

 

[Fnewman]

Around here it is rare to see anything but 200A in most houses up to sf limits set by various AHJ (varies some). Then it is 400A.

 

[peter d]

In my area, a smaller new house with all gas appliances and high efficiency central a/c will almost always have a 100 amp service.

 

[JFletcher]

The difference in load calculation for that 1700 sq ft difference is 5100VA or only 21.25amps on a 240V service.

This.

In this area, it's fairly unusual to see 100A services; most are 125+A... even this house has a 125A FPE panel ca 1953 in it. Most everything is electric here tho; gas wasnt widely available until the late 80s, so electric baseboard heat, electric dryer, oven, stove, dryer, water heater, and HVAC. Add in well pump, garbage disposal, toaster, microwave, coffee pot (SABCs), washing machine, etc etc and its quite possible to 'need' a 200A service. Practically tho, we do full house generators in the 18-24kW range, so you'd really have to try to exceed 75A unless there are 2+ HVAC units, spa, and so on.

Like Peter D mentioned, new homes with gas appliances can easily get by with 100A services.

eta: Greg, were they aluminum wire, or late 70s with copper?

 

[Greg1707]

ALUM. Including the GEC to water pipe.

This.

In this area, it's fairly unusual to see 100A services; most are 125+A... even this house has a 125A FPE panel ca 1953 in it. Most everything is electric here tho; gas wasnt widely available until the late 80s, so electric baseboard heat, electric dryer, oven, stove, dryer, water heater, and HVAC. Add in well pump, garbage disposal, toaster, microwave, coffee pot (SABCs), washing machine, etc etc and its quite possible to 'need' a 200A service. Practically tho, we do full house generators in the 18-24kW range, so you'd really have to try to exceed 75A unless there are 2+ HVAC units, spa, and so on.

Like Peter D mentioned, new homes with gas appliances can easily get by with 100A services.

eta: Greg, were they aluminum wire, or late 70s with copper?

 

[Dennis Alwon]

I agree the difference is sq.ft is not that significant and given that a 200 amp panel is probably cheaper than 150 amp panel I believe that is why there are 200 amp services at both houses. All electric house is automatically a 200 around here and depending on size and number of heat pumps it can easily be 400 amps.

 

[kwired]

This week we replaced panels in two houses built in the 1970s. Both are all electric. One was a 1,100 square foot town house and the other was a 2800 square foot ranch house with basement. No pools or anything extra.

:? Both houses had 200 amp services.

Maybe one house was oversized and the other was undersized?

My house is closer to fitting your 2800 square foot one and is also all electric. I have a 200 amp service to it, but would guess if I put in a 100 amp main it may trip on rare occasions, make it a 125 amp main and it probably would never trip. POCO only has a 25 kVA transformer supplying not only the house but some other outbuildings, they don't expect to see high load for any long period of time either.

 

[JFletcher]

ALUM. Including the GEC to water pipe.

Joy.

 

[mtfallsmikey]

Some of you remember the days in the 60's and 70's when PEPCO (Potomac Electric POCO) here in Va., Md., D.C. promoted all-electric homes, they were called "Gold Medallion" homes, with a badge placed on the front door.... they all had 200A services

 

[readydave8]

200 amp used to be status symbol around here until we started seeing more large homes with 400 amp services. Usually overkill in both cases

 

[mlnk]

Tesla

Tesla

My son's Tesla charger uses 72 amps continuous load.

 

[peter d]

200 amp used to be status symbol around here until we started seeing more large homes with 400 amp services. Usually overkill in both cases

My meter socket is bigger than yours!!

:huh::?:roll::roll:

 

[kwired]

My son's Tesla charger uses 72 amps continuous load.

Does that mean it draws that current level for 3 hours or more?

That is ~17.28 kW and at 10 cents per kWhr would be $1.73 an hour to charge. How far can you drive on 1 hour of charge? If it were in state of full discharge does it take more then 3 hours to fully charge at that high of a charging rate?

 

[Open Neutral]

200 amp used to be status symbol around here until we started seeing more large homes with 400 amp services. Usually overkill in both cases

I was in a house along the causeway between Miami and Miami Beach.
It had 800 amp service. And a backup generator, and .......

 

[kwired]

I was in a house along the causeway between Miami and Miami Beach.
It had 800 amp service. And a backup generator, and .......

I installed 4-200 amp main breakers in a house once, but that was partly because it cost less to do it that way then to put in a single main ahead of the four panels that likely could have been 400 amps.

 

[wwhitney]

That is ~17.28 kW and at 10 cents per kWhr would be $1.73 an hour to charge. How far can you drive on 1 hour of charge? If it were in state of full discharge does it take more then 3 hours to fully charge at that high of a charging rate?

Teslas have batteries sized from 60 to 100 kWh, so a Tesla certainly could draw 17 kW continuously for over 3 hours. As for how far you can go on a given charge, that depends on your speed, driving style, temperature, etc. But I think you can get 3 mi/kWh at freeway speeds without much trouble, which would be 50 mi/hour of charging at 17 kW.

Cheers, Wayne

 

[kwired]

Teslas have batteries sized from 60 to 100 kWh, so a Tesla certainly could draw 17 kW continuously for over 3 hours. As for how far you can go on a given charge, that depends on your speed, driving style, temperature, etc. But I think you can get 3 mi/kWh at freeway speeds without much trouble, which would be 50 mi/hour of charging at 17 kW.

Cheers, Wayne

If I follow correctly and the electric rate is 10 cents a kWhr, then that means it cost about $1.70 to travel 50 miles at freeway speeds?

Compared to a car that gets 30 MPG, and lets say $2.25/gallon gas - it should cost about $3.74 to travel 50 miles.

If the car gets around 110-115 MPG then your energy cost is about same for either, at the energy rates mentioned.

If enough people get EV's, will electric rates go up, or at least have some higher demand rates if you charge your vehicle at the wrong time of day? May already be seeing this in some instances?

 

[Fulthrotl]

Some of you remember the days in the 60's and 70's when PEPCO (Potomac Electric POCO) here in Va., Md., D.C. promoted all-electric homes, they were called "Gold Medallion" homes, with a badge placed on the front door.... they all had 200A services

SCE did the same gold medallion rollout in the 60's here.

my house is one of them. someone changed out the gold medallion
doorbell for a funky one... i'm looking for an original one to replace it.

SCG sued SCE, and won, as the gold medallion program here *prohibited*
gas service from being available on the property. in the late 60's, they added
gas to the entire tract, and SCE paid for the retrofit. restraint of trade was a
compelling argument, and edison lost.

my parent's house in 1962 was gold medallion, and had an electric pool heater.
and a 400 amp service. the first month we turned on the pool heater, the
electric bill was larger than the mortgage payment. we never did that again.
i was only 7, but remember standing in front of the electric panel, listening
to the sound of the meter spinning when the pool heater was on.

you could actually hear it whirring in there.

https://www.thespruce.com/gold-medallion-home-definition-1821516