Electrical Experts - 400 amp service questions

[Weedwaka]

Hey Guys,

I am in the planning stages of building a new shop with a suite above it which will serve as our house for five or so years, at which point we will build the main house.

I have to choose between a 200 amp and 400 amp main service to the shop. The cost of the 200 amp service is about 800.00 and the 400 amp is 1700.00 .

The cost to add an additional 200 amp service to the house at a later date adds up to a little bit more than the 1700.00 initial cost of the 400 amp service.

So my questions:

1. Will I need a 400 amp main circuit panel ( $$$ ) or is there a way to split this into two , 200 amp circuit panels ?

Is there any other expenses that I should be aware of before I pull the trigger on a 400 amp service ?

 

[porschedude996TT]

Hey Guys,

I am in the planning stages of building a new shop with a suite above it which will serve as our house for five or so years, at which point we will build the main house.

I have to choose between a 200 amp and 400 amp main service to the shop. The cost of the 200 amp service is about 800.00 and the 400 amp is 1700.00 .

The cost to add an additional 200 amp service to the house at a later date adds up to a little bit more than the 1700.00 initial cost of the 400 amp service.

So my questions:

1. Will I need a 400 amp main circuit panel ( $$$ ) or is there a way to split this into two , 200 amp circuit panels ?

Is there any other expenses that I should be aware of before I pull the trigger on a 400 amp service ?

When I was looking at houses being built recently in Huntsville / Madison area, I found that these houses had two 200amp services to them. I'm thinking it was cheaper to build? There were two direct bury service entering the houses and they were single family dwellings. I saw them in different stages, some with just the ground work done and others that had two 200amp service entrance panels. I can't recall if they have two meters. Maybe the meter was elsewhere in a vault towards the property line???

 

[mrb]

the way this is typically done is you have a class 320 meter (400 amp services typically have a 320amp meter on residential) and two 200amp disconnects. 200amp breakers are much, much cheaper than a 400amp. There are meter/mains with the socket and the two breakers or some installs use a meter can and seperate disconnects.

 

[malodin]

I say do the 400 amp to stat with, can never have to much power. i am taking my existing 200 amp service disconnect(being a mobilehome) and installing next to it a 400 amp meter base that will house my current 320amp meter and then running out to the garage a 200 amp panel and using the current 200 amp service disconnect as a pass through from the 320 amp meter panel to the mobile home(have to stay in code for the mobile home) if the place had had a 400 amp meter base to begin with i wouldnt be having any of these problems but oh well....

by the way on the average the panels and meterbases only cost 150-300 so say another 400 in wire and misc. that means you are paying 1000 in labor, are you digging the ditches and stuff? or was that all quoted in?

 

[CraigFL]

My building has 400A service and it is 3 phase. This is very nice because I can use 3 phase power at times for High power devices -- welders, heaters, etc.

 

[malodin]

My building has 400A service and it is 3 phase. This is very nice because I can use 3 phase power at times for High power devices -- welders, heaters, etc.

you have no idea how lucky you are, here in my neck of the woods 3 phase power in residential is very very rare and even more harder to get and it costs alot of money to have 3 phase brought in.

 

[walrus]

I'd say have an electrician do the calculations to see what size service you need

 

[ArthurPE]

I agree, go 400A with 2 200A subfeeds...one for the shop, one for the home...

check the homes load, maybe a 100 or 150 will do, sounds small if it's above a shop...

 

[Weedwaka]

by the way on the average the panels and meterbases only cost 150-300 so say another 400 in wire and misc. that means you are paying 1000 in labor, are you digging the ditches and stuff? or was that all quoted in?

We have to dig the ditch, run the pipe etc. The 1700 is the rate bc hydro charges to hook us up and pull the cable from the box across the street. They have to go under the road though.

 

[nate379]

What do you need 400amp on a residence for?

Hell my folks run on 100amp power and that is the house, 2 garages and my Dad's shop.

 

[Weedwaka]

I'd say have an electrician do the calculations to see what size service you need

This is a little off the original topic but I will try to explain where we are coming from.

The electric on demand water heater that we want to run is recommended for a minimum 200 amp service ( 3x 50 amp breakers ). The one we can get a great deal on is recommended for a minimum 300 amp service ( 3 x 60 amp breakers ).

If we ran just a regular electric hot water tank in the garage, we could probably get away with a 200 amp feed with just enough for both. I would really prefer the 400 amp setup ( or 320 mentioned above ) to give a little more head room but am worried about cost.

Eventually when the house is built it will be hooked up to gas, but not the garage. Most likely, the house will have a gas range, gas on demand boiler for radiant heat and hot water etc so that will not be taxing the electrical system.

 

[Weedwaka]

What do you need 400amp on a residence for?

Hell my folks run on 100amp power and that is the house, 2 garages and my Dad's shop.

Do they utilize gas for heating, hot water and cooking ? Our garage is all electric heating and hot water. Add the compressor, welder etc and it starts to add up.

 

[mrb]

nevermind...............

 

[ArthurPE]

the 3-60 unit draws 150A...I'm not sure I'ld want that surging thru my walls...
the cable is going to be expensive...
the energy savings minimal on something used seldom...

why not just a regular tank 20-30 A?
insulate it well, and keep the setpoint low...

 

[ArthurPE]

gas vs. electric

electric
40 gal
4.5 kw
90% eff
effective 4 kw hr heating

gas
40 gal
36000 btu/hr ~ 36 cf/hr ~ 10.5 kw hr (using 1000 btu ~ 1 cf)
60% eff
effective 6.3 kw hr heating

electric ~$0.075/kw hr
gas ~$5/ccf (using the Columbia gas calculator)

1 hour running:
electric 4.5 kw x $0.075 / kw hr x 1 hr ~ $0.34
$0.34/4 kw hr ~ $0.085/kw hr of heating

gas 36/100 x $5/ccf ~ $1.80
$1.80/6.3 kw hr ~ $0.29/kw hr of heating

what did I miss?

 

[mrb]

gas vs. electric

electric
40 gal
4.5 kw
90% eff
effective 4 kw hr heating

gas
40 gal
36000 btu/hr ~ 36 cf/hr ~ 10.5 kw hr (using 1000 btu ~ 1 cf)
60% eff
effective 6.3 kw hr heating

electric ~$0.075/kw hr
gas ~$5/ccf (using the Columbia gas calculator)

1 hour running:
electric 4.5 kw x $0.075 / kw hr x 1 hr ~ $0.34
$0.34/4 kw hr ~ $0.085/kw hr of heating

gas 36/100 x $5/ccf ~ $1.80
$1.80/6.3 kw hr ~ $0.29/kw hr of heating

what did I miss?

interesting, i always thought is was alot more expensive to heat with electric.....

 

[nate379]

No the water heater, dryer and oven are all electric. The water heater isn't used in the winter though since the wood stove heats the domestic hot water.

Heat is wood with an oil furnace backup. Same in the shop and the other garage just has an oil furnace.

My house in Idaho was all electric. Heat, dryer, water heater, etc and it was on 100 amp as well.

Do they utilize gas for heating, hot water and cooking ? Our garage is all electric heating and hot water. Add the compressor, welder etc and it starts to add up.

 

[nate379]

All depends where you live. I don't know of many places that have $0.07 kw/hr electric even. Idaho was dirt cheap to live and electric was 0.09 or 0.10 per kw/hr.
Here it is $0.19 kw/hr
Everything in my house that can run on gas does other than the dryer and I'm probably going to buy a gas unit.

Gas is right around $1 ccf after all the taxes and fees. It is actually cheaper to heat with gas than wood unless I get the wood for free.... and still after my time, fuel and wear and tear on equipment... it's not that great of a cost savings.

gas vs. electric

electric
40 gal
4.5 kw
90% eff
effective 4 kw hr heating

gas
40 gal
36000 btu/hr ~ 36 cf/hr ~ 10.5 kw hr (using 1000 btu ~ 1 cf)
60% eff
effective 6.3 kw hr heating

electric ~$0.075/kw hr
gas ~$5/ccf (using the Columbia gas calculator)

1 hour running:
electric 4.5 kw x $0.075 / kw hr x 1 hr ~ $0.34
$0.34/4 kw hr ~ $0.085/kw hr of heating

gas 36/100 x $5/ccf ~ $1.80
$1.80/6.3 kw hr ~ $0.29/kw hr of heating

what did I miss?

 

[Weedwaka]

The reason for the all electric garage hook up is as follows ,

We both work and are gone all day. This means that all day and all night except for evening showers and some warm water to wash our hands, we do not use any hot water. We cold water wash all our clothes. Our dishwasher will be run maximum twice a week. The savings over even a highly efficient hot water tank is there.

We are applying for positions out of town ( shift work ) that will have us away for weeks at a time. The electric point of use unit is better suited for this type of lifestyle.

When we hook up to gas, we will be paying a base charge to the gas company every month just for being able to use their product. This is better spent on electricity until we have a higher demand for heating ( house ) .

People assume that gas is always more efficient. This is only true for long draws of hot water through a gas point of use heater. For short draws and infrequent use, you can not beat the electric on demand. It kicks the gas units ***.

 

[Weedwaka]

the 3-60 unit draws 150A...I'm not sure I'ld want that surging thru my walls...
the cable is going to be expensive...
the energy savings minimal on something used seldom...

why not just a regular tank 20-30 A?
insulate it well, and keep the setpoint low...

Actually, the opposite is true for this case. For seldom use, the electric point of use unit is much more efficient. Heating that tank of water all day and all night is costly even with an highly efficient unit.

The point of use heater we are looking at would come at substantial savings over retail also. This would help offset the additional costs for the 400 amp service a bit.

We have looked at units such as the Marathon electric tank heaters. If one would fall from the sky tomorrow for a great deal, we would look again at going that route.

Thanks for your input

 

[ArthurPE]

All depends where you live. I don't know of many places that have $0.07 kw/hr electric even. Idaho was dirt cheap to live and electric was 0.09 or 0.10 per kw/hr.
Here it is $0.19 kw/hr
Everything in my house that can run on gas does other than the dryer and I'm probably going to buy a gas unit.

Gas is right around $1 ccf after all the taxes and fees. It is actually cheaper to heat with gas than wood unless I get the wood for free.... and still after my time, fuel and wear and tear on equipment... it's not that great of a cost savings.

I lived in AK for 10 years...
I thought Palmer only had propane...who's the ng service provider?
$1/ccf is dirt cheap...

although I can see power costing $0.19, it's probably oil generated...
or gas from the Anchorage plant

no matter how you cut it it's a 300% swing in my clacs, so even if power doubles and gas remains the same, electric is cheaper...same if gas is 1/2 as much...

here's a good power reference US average ~11 cents
http://www.eia.doe.gov/cneaf/electricity/epm/table5_6_a.html
I live very close to WV 7.72 cents...

gas prices
summary http://tonto.eia.doe.gov/dnav/ng/ng_pri_sum_dcu_nus_m.htm
by area http://tonto.eia.doe.gov/dnav/ng/ng_pri_sum_a_EPG0_FWA_DMcf_a.htm

average ~$12/ccf (AK average $6/ccf)
equivilent power <$6
1/2 as much....

like you said, all depends where you live...

 

[porschedude996TT]

I agree, go 400A with 2 200A subfeeds...one for the shop, one for the home...

check the homes load, maybe a 100 or 150 will do, sounds small if it's above a shop...

I'm guessing a 50amp welder in each room of the house???

 

[malodin]

what it boils down to is there is no such thing as having to much power, just because the capability to add welders and machinery that require alot of amps is there does not mean you will be using that capability. having access to the power is where you need it, just like building a garage No one has ever said GEE I WISH I HAD BUILT IT SMALLER!!! I promise you once you have the capability of the 400 amp service you will never say GEE I SHOULD HAVE ONLY GONE WITH THE 200 AMP

 

[Weedwaka]

Thanks for the replies guys. 400 amp with dual 200 amp panels looks like the way to go.

 

[Weedwaka]

NEW QUESTION

Can I run a 400 amp service / 400 amp meter base to the shop / suite and just install a 200 amp panel for now. My thinking is that this would give me the room to run another 200 amp panel to the house at a later date .

Any suggestions from the pro's ?

 

[mrb]

NEW QUESTION

Can I run a 400 amp service / 400 amp meter base to the shop / suite and just install a 200 amp panel for now. My thinking is that this would give me the room to run another 200 amp panel to the house at a later date .

Any suggestions from the pro's ?

you cant have more that one supply to the house (or any other building). So if you have a service at the house already, you cant run another one to it from your shop.

 

[malodin]

I can only speak from what i learned on my project.

1st my wires going to my original 200 amp meter and base were big enough to carry the 320/400 amp so no new wires from my transformer across the street to my house, thus i was able to install my 320/400 meter and base next to my old 200 amp old meter and base, then off the new 320/400 meter/base i ran a 200 feed to the garage, and looped a 200 feed into my old meter panel and base(had to use a pass through block off plate) thus allowing me to keep my 200 amp service to the house and a 200 amp service to the garage.

 

[kvom]

Same for me as malodin.

A bigger panel (i.e., 200a vs. 100a) is that you can provision more circuits, even if the current draw at any one time is low. My garage panel has 7 220V circuits that use up 14 slots.

 

[malodin]

on my garage panel the difference between price of a lesser circuit and the full maxed out panel(i think something like 42 circuits) was like 20$ so i went with the biggest residential circuit panel just because.

 

[Weedwaka]

you cant have more that one supply to the house (or any other building). So if you have a service at the house already, you cant run another one to it from your shop.

The lot is still empty at this point ( no house or garage ) . Just a lot of scribbles on paper

 

[malodin]

if it is empty you can easily run the 400 amp panel and meter at your garage then sub feed it to your house(unless its going to be a mobile home then you have to have a mobile home disconnect service)

 

[Weedwaka]

So I can have a 400 amp meter on the new garage with a 200 amp panel for a few years ? Then when we build the house, we just run a line from the 400 amp panel at the garage to feed the new 200 amp panel in the house ?

 

[Charles (in GA)]

So I can have a 400 amp meter on the new garage with a 200 amp panel for a few years ? Then when we build the house, we just run a line from the 400 amp panel at the garage to feed the new 200 amp panel in the house ?

YEP.

Just make sure they charge you residential rates.

Charles

 

[nate379]

http://www.enstarnaturalgas.com/CompanyInfo/rate_info.htm

It's $0.98 per ccf and a $9.00 per month flat fee plus 0.271% of the total bill added.

So it's a bit more than $1.00/ccf I guess but it's not close to $6 for sure.

Electric is made by burning natural gas to make steam I think. I know it's from gas for sure.

I lived in AK for 10 years...
I thought Palmer only had propane...who's the ng service provider?
$1/ccf is dirt cheap...

although I can see power costing $0.19, it's probably oil generated...
or gas from the Anchorage plant

no matter how you cut it it's a 300% swing in my clacs, so even if power doubles and gas remains the same, electric is cheaper...same if gas is 1/2 as much...

here's a good power reference US average ~11 cents
http://www.eia.doe.gov/cneaf/electricity/epm/table5_6_a.html
I live very close to WV 7.72 cents...

gas prices
summary http://tonto.eia.doe.gov/dnav/ng/ng_pri_sum_dcu_nus_m.htm
by area http://tonto.eia.doe.gov/dnav/ng/ng_pri_sum_a_EPG0_FWA_DMcf_a.htm

average ~$12/ccf (AK average $6/ccf)
equivilent power <$6
1/2 as much....

like you said, all depends where you live...

 

[Weedwaka]

We have hydro electric power plants up here in British Columbia.