2-2-4-6 vs. 2-2-2-4
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n8n
Well-known member
how much of your load is 240 vs. 120?
Aceman
Well-known member
You can't use #2 aluminum for 100 amps feeding a shop. 90 amps is the limit.
This is mostly a woodshop, I'll have a table saw and jointer running 240 rated at about 15 amps each. I may install a 240 volt dust collector down the road that would run at the same time and they seem to be less than 15 amps typically. Everything else is 120, but I want to keep my options open for adding more 240 if something comes along... may even take up welding some day 
.
.Too little information. How long is your run between main panel and garage subpanel??
What REAL loads will you have in garage as 90A likely impossible for you to overload with one person??
MHF Al 2-2-2-4 is screaming bargain and often perfect feeder for 90A in garage.
What REAL loads will you have in garage as 90A likely impossible for you to overload with one person??
MHF Al 2-2-2-4 is screaming bargain and often perfect feeder for 90A in garage.
The run is right around 150' so voltage drop would be over 3% with 2 guage wire... giving more like 75 amps. Real loads would be lights on while running a 220v 15 amp table saw at the same time as a 220v 15 amp dust collector. I may put in a 220v compressor and get a welder some day, but probably will limit them to 30 amp circuits... I'm not sure what kind of real load to expect from something like that. I want to make sure I'm putting in something that doesn't limit me. Is the consensus that a one-man hobby shop is OK with this?
sberry
Banned
Yes there is a difference and you should shop wire a bit more. Even at that would give up 20 cents a foot to use the larger wire. While one can pontificate about the types of loads the reality is many are 120V or out of balance even while using 240V which makes the wire more loaded and increases any effect on that portion that is running on 120.
All this may be moot in the grand scheme due to the nature of loading, some drop down the N may bot matter if there are arleady 240 loads,,, this is all a bit of mental ************ but upsizing the N and the G cant hurt.
This wire is way sufficient for a hobby shop and then some and the cost difference is 29$ for this run to use the 2 2 2 4 which is really a lot better.
All this may be moot in the grand scheme due to the nature of loading, some drop down the N may bot matter if there are arleady 240 loads,,, this is all a bit of mental ************ but upsizing the N and the G cant hurt.
This wire is way sufficient for a hobby shop and then some and the cost difference is 29$ for this run to use the 2 2 2 4 which is really a lot better.
Thanks sberry. Your answer helps quite a bit. I think the biggest concern I have is will 2-2-2-4 be enough for my needs running 150 feet? This gives <3% voltage drop at 75 amps. Is the consensus that it'd be next to impossible or at least highly unlikely that I'd ever have any problems with this feeder for a typical hobby shop?
theoldwizard1
Well-known member
Most hobby shops are fine with 60A. The exception to that is if you are running electric heat or A/C and want to run a plasma cutter, which requires you to run your compressor. That is 3 big 240V loads. Simple solution: turn off the HVAC while using your plasma cutter.
AndyA
Well-known member
A decent sized welder may need to be on a 60 amps circuit by itself. A 300 amp transformer welder may need a 100 amp circuit to fully feed it.
If you think you may get into welding, go ahead and install enough electric service to handle it.
It's cheaper to install it correctly once, than to install it twice!
If you think you may get into welding, go ahead and install enough electric service to handle it.
It's cheaper to install it correctly once, than to install it twice!
nafterclifen
Well-known member
For only $135, spend the extra money on the larger cable. You'll be able to rest easy knowing it's more than capable. Make more money tomorrow. Do it once, do it right.
sberry
Banned
You would need to add a ground wire to the larger wire. I agree the cost here isn't a deal breaker but,,, I agree with the 60A hobby shop assessment. Over 30+ years must have wired near a couple dozen garages with number 2 alum and a 60. A couple of them have been quite active including one a bud mechanic daily in for 3 decades and a 5 hp comp and,,, I have never and his could be repeated never had one call with a tripped breaker. 150 ft isn't too bad, I one time ran a shop from 200 ft of it.
Modern welders call for 50A and the compact mig uses half of that, while there is a place for a 300 synch it really isn't in most hobby shops, weighs a 1000# is huge and really should have 100A. There is so much better, I havnt turned mine on in years.
Modern welders call for 50A and the compact mig uses half of that, while there is a place for a 300 synch it really isn't in most hobby shops, weighs a 1000# is huge and really should have 100A. There is so much better, I havnt turned mine on in years.
sberry
Banned
Whoops, guess I read it wrong, it does have a ground.
This is somewhat related but there is a lot of parked money "just in case". I understand where the labor is so hi another buck a foot doesn't really mean much. But it is a little different question than asking is a number 2 adequate and the answer is yes. You need to give overhead to things like pottery kiln and heavy air condition and instant hot water and air comps above 5 hp.
So many of the new tools have been classed with this in mind. The home/hobby gang has really driven the market for a 200 compact feeder and while the use goes way up when a guy buys one, some for lights but the machine draws 1/2 the current of a tombstone buzzer.
Same for the 22A comp, it might be legal to run it from a 10/30 circuit. You run a little more but the peaks are less especially with intermitant tools. The trend is nw smaller lighter and more efficeient vs having big hog stuff most of which is obsolete and or un needed.
This is somewhat related but there is a lot of parked money "just in case". I understand where the labor is so hi another buck a foot doesn't really mean much. But it is a little different question than asking is a number 2 adequate and the answer is yes. You need to give overhead to things like pottery kiln and heavy air condition and instant hot water and air comps above 5 hp.
So many of the new tools have been classed with this in mind. The home/hobby gang has really driven the market for a 200 compact feeder and while the use goes way up when a guy buys one, some for lights but the machine draws 1/2 the current of a tombstone buzzer.
Same for the 22A comp, it might be legal to run it from a 10/30 circuit. You run a little more but the peaks are less especially with intermitant tools. The trend is nw smaller lighter and more efficeient vs having big hog stuff most of which is obsolete and or un needed.
sberry
Banned
On the other hand its a bump over a hundred bucks for a way better wire. Not much considering the cost of the rest of the install. In reality you will never use it. Its one of the reasons we like service from an existing service is that 95% of the time its at idle. In the end its how much you want to gobble up, minor welding, some air, light appliance use or hoist are almost irrelevant in terms of demand.
Thanks for taking the time to respond. I decided to trust in you guys' knowledge and went with the 2 2 2 4. Besides, I think the guys at the supply house think I'm crazy for even considering upsizing. In the end, you guys with the knowledge and experience that I don't have sound plenty confident for me. Thanks for all the help!