100A - enough?

[ForceFed70]

Related to discussion in this thread: http://www.garagejournal.com/forum/showthread.php?t=276096

Wanted to poll the GJ masses to see if anyone has actually had an issue with 100A not being enough. The assumption being that this is a typical backyard garage for a homeowner or hobbiest rather than a commercial shop or a business.

My experience is that I was able to make 50A work with minor concessions (did not run the welder, compressor, and powder coating oven at the same time - almost never had a need to do that anyway) and 100A has been plenty for my needs in every scenario I`ve encountered so far.

If you have found that 100A is not enough, please reply to this thread with more information - why wasn`t it enough.

 

[1Garageman]

100amps should be PLENTY of power for you!

 

[larry_g]

My old shop contained a freezer, an electric heater for the office, water heater, welder, a few machine tools in the 1-2 hp range, air compressor . It was all driven through an 80A breaker in the house panel. In the years in that shop I can only remember popping the breaker a couple of times.

lg
no neat sig line

 

[jkwilson]

For home use with a single person working there, 100A is plenty unless you have a specific piece of equipment that draws significant current and doesn't need an operator. Something like an oven might be worthy of adding capacity since you might want to weld while powder coating.

But then again, it hasn't been that long ago that homes were built with 60A service and now people are going with 5 times that.

 

[Alan Douglas]

My house has 60A service and the barn is on a 30A 240V feed (installed in 1950). I don't blow fuses despite having three 2HP motors, electric range and dryer and upright freezer. Granted I did have to play a few tricks to run those motors (use repulsion-induction with lower starting currents, or use series resistors to limit the current).

Yes 100A would be better, but I could never quite understand the rush for "more" when we ought to be conserving and using "less."

 

[ForceFed70]

Excellent feedback so for - thanks guys!

To the person who indicated they wish they had more than 100A: Could you please share your situation for us so we can see if it may apply to others? Why isn`t 100 enough?

 

[themiller]

As electric cars become more prevalent I can see "garage people" needing > 100A service in the garage. Two cars at 40-80A each charging away at night and there you go. I will be putting in 60A service shortly as that was the biggest I planned for (conduit limited) but seeing as the Tesla (and others I'm sure...) can dual charge at 80A I slightly regret my decision.

I voted "Have less than 100A - Causing problems and wish I had more." because I only have 15 until it warms up and I can pull new wire for 60... 15 is not enough between a compressor, heater, and lighting.

 

[VictorBravo]

75 Amps was what I could afford when I built the shop, and I've never needed more. The only issue might be I'd have to turn off a 30 amp electric heater to stick weld, but I'd be welding with the door open anyway.

 

[ForceFed70]

As electric cars become more prevalent I can see "garage people" needing > 100A service in the garage. Two cars at 40-80A each charging away at night and there you go. I will be putting in 60A service shortly as that was the biggest I planned for (conduit limited) but seeing as the Tesla (and others I'm sure...) can dual charge at 80A I slightly regret my decision.

Good point. Tho It`s pretty hard to predict the future and many times you predict wrong. Just ask all of those people who future proofed their homes by running coaxial cables to every room when they should have ran Ethernet.

Even with an 80A charger circuit on a 100A panel: The charger would rarely draw more that 60 actual amps. The 40A left over would go a long way. For most of us there would be the odd time we`d need to unplug the car, but it wouldn`t be an every day occurrence.

 

[LX-Markham]

when/if ever need to charge the Tesla, use a gas powered generator

 

[77thor]

100A should be more than enough for just a garage/shop,
but if that also includes your house... maybe not.

 

[why worry]

I currently have 100amp service and it doesn't quite do it under certain conditions:
1. XMT 304 welding about 30 amps
2. 3HP compressor starts up 12 amps + start up
3. 2 HP well running 8 amps+start up
4. Lights on in shop 10 amps
5. 2 freezers and a frig 18 amps
6. shop stereo and misc 10 amps
When I am working in my shop I have to be sure to not have the air on when welding in case my well starts up. I have tripped the main on inrush current as I am right at capacity at the right time.

 

[themiller]

Good point. Tho It`s pretty hard to predict the future and many times you predict wrong. Just ask all of those people who future proofed their homes by running coaxial cables to every room when they should have ran Ethernet.

Even with an 80A charger circuit on a 100A panel: The charger would rarely draw more that 60 actual amps. The 40A left over would go a long way. For most of us there would be the odd time we`d need to unplug the car, but it wouldn`t be an every day occurrence.

But I want 2 of them

To be fair - I hear ya.

 

[CNGsaves]

^ ^ Still would want to charge the Tesla at off-peak hours/charges so still may not be a problem. Those chargers really should have timers so they kick on during middle of night.

Most demand will be on ALL-Electric shops where they rely 100% on electric for forced air heat/radiant floor heat, hot water tank, welder, compressor, etc. These shops might be borderline on actually needing full 100 amp at times.

 

[Catadj78]

What is the price difference between the 100 amp and 200 amp?

Meter box? Exterior and interior panel? What else do you need different than 100 amp?

 

[hh76]

What is the price difference between the 100 amp and 200 amp?

Meter box? Exterior and interior panel? What else do you need different than 100 amp?

Service, not much different. Sub panel can be significant.

 

[Catadj78]

Service, not much different. Sub panel can be significant.

If someone was going to have a totally separate meter from the house.

2 power bills.

I have 2 lots and both are corner lots.

Power comes into the house from the front yard and the shop will be approximately 100' from the house. Shop will be less than 40' from an existing power pole by the road. I am not running power from the house to the shop, I would rather have 2 power bills.

This way, how much $$ difference in 100 amp vs 200 amp. I am seeing very minimal difference.

 

[hh76]

Minimal in most cases.

 

[James-W]

When I built my garage I put in a new 200 amp electrical service. The only cost difference was the cost of the electrical panel. The power company ran the lines from the street to the garage for free and hooked them up. Why would I not want to have the 200 amp service when the only extra cost is for the panel? Whether I will ever actually need that much power or not really isn't the issue. Point is, if I ever do need it I will have it available, or if the wife and I sell the house the next people who own it may have a need for it. Either way, it doesn't hurt anything to have a 200 amp service.

 

[Elginz]

I have 200A in the shop and feed to the house. Two 100A sub-panels in the house to feed 2 dryers, double oven, 5500W water heater,well pump. I heat the shop (3000W), and studio (3000W), 4500w water heater in the studio, I don't recall the wattage on the house heat, but it uses a 30A, and a 60A breaker. In the summer a couple of air conditioners.

When I asked about adding a 30-40Amp kiln the power company said I was fine.
I have a second meter for the power company to control peak demand. The meter cost me $24.45 a month, but brings the KW cost for those things to $.049 per KW from $.1268. My back heat up is LP, with a gas cook top, about 300 gallons of LP a year.

The shop would be fine for a long time with 100 amp. Saws, compressor, welder, fans, or dust collectors. I don't have that many hands to run even these that would not come yet trip any breakers.

P.S. The shop is the attached 24x24 garage (at one time it was not attached). The studio has 60 amp to it, just across the driveway.
Guess I din't answer any thing anyway.

 

[600SL]

When I built my garage I put in a new 200 amp electrical service. The only cost difference was the cost of the electrical panel. The power company ran the lines from the street to the garage for free and hooked them up. Why would I not want to have the 200 amp service when the only extra cost is for the panel? Whether I will ever actually need that much power or not really isn't the issue. Point is, if I ever do need it I will have it available, or if the wife and I sell the house the next people who own it may have a need for it. Either way, it doesn't hurt anything to have a 200 amp service.

Exactly in my case the difference between 100 amp and 200 amp was $60. Because the power company brought the line in.

In the case where I would have brought the cable out from the house myself it would have been more by the cost of the cable

200' of cable at $0.70/ ft price difference.
a new 320 amp meter pan at the house. Which I probably would have had to do anyway because the house is 200 amp. so what size meter pan do you use for a dual service of 200amp/100amp verses 200amp/200amp. I believe both would require a 320 amp pan.

 

[plow]

I'm diggin this thread. I'm now sold on a sub panel for the shop instead of a separate service. I do think I'll put in a 125A breaker though.

 

[plow]

BTW, about how much is a 125A Square D breaker?

 

[Falcon67]

I've got 960 sq/ft, using electric heat, has two AC units, lots of 240V equipment, lots more 120V equipment and the run is fused at 70A. No trips.

 

[sberry]

You have to work to overload a 100A service. I have seen overloaded 60 with all electric appliances, family and one of the real deal killers was a microwave believe it or not. With everything else running a supper it couldn't take it or was hot.
Ironic thing is that eventually after we upgraded it piped gas came and it all got converted. We did connect a garage to it but it really didn't add simultenous demand but now have 200 and the 60 and definitely a 100 would have been well adequate.

 

[sberry]

I am doing one now where I am replacing a 100 with a 100 and the only reason I am not doing 200 is that I have most of the materials for it. If I had to buy it then it or going underground would be 200. Panels are priced all over the place and often the gread deal is the starter pack. The thing came with 6 breakers and was on sale for less than the stand alone price and with alum wire it all comes out to about a hundred more for 200. Not much.
I am going to let a generation past me to worry about it. I added some kitchen circuits but remove the range in favor of gas and there could be a possibility of doing the dryer and hot water from it if needed. It doesn't have AC but with the range out there would be enough overhead for a modest unit.
Something to consider is the actual demand, water heater and dryers are on 30 but the actual is 25, you don't usually run the stove on high all 4 with broiler and many an AC on a 30 with an actual of 15.