Yet another sub panel question...

[CTyler]

A 60 amp panel will get you by but I can see maxing it out on a regualr basis for nominal loads.

Not everything will run at the same time but you will have things cycling. For example Oil furnace 18 amps, Air comp 14 amps, batt charger 3-10amps, block heater 9 amps, water pump 15 amps, lights 10 amps, welder 20 amps, plus other misc stuff, ceiling fans, tv, radio, coffee pot, etc, etc. Heaven forbid you have electric heat.

What about future needs?

 

[Jeff396]

All of the really high draw cycling type items will remain in the main panel. The basement sub panel will only handle 110v plugs and lighting plus an entertainment center (tv, stereo, dvd, vcr etc), an effluent pump and a heater/exhaust fan for the bathroom. I don't have many shop tools at the moment but I don't forsee a time where I will want to power more than one at a time.

Jeff

 

[Jeff396]

There is a slight possibility that I may have to move the compressor to the sub panel. I have installed two half breakers in the main to supply the basement lights and one half breaker to supply the plugs in the hobby room only. These I know will be easy to transfer to the sub. I also need to come up with one more builder installed half breaker to be moved. If I have trouble I will need to move the compressor and use those two slots for the sub panel breaker. If I have to do this and plug it into the formula I come up with

square footage * 3 = 9000
heater watts .........=1500
compressor watts ..= 4800
............................ 15300/230 = 66.5 amps

I might just go with the 100 amp in that case and the 60 if the compressor remains in the main. I do understand the difference between the bonding of the common in the main but not in the sub where the ground is only bonded. I have been reading just about everything I can get my hands on but thanks for the heads up

Jeff

 

[tdenny]

Unless you are running your table saw and dust collector at the same time. /forums/images/graemlins/smile.gif

 

[Jeff396]

Never really thought I'd need one of those.....all the dust makes me feel like I'm accomplishing something. /forums/images/graemlins/smile.gif But just for yucks, how many watts does one of those eat up? No matter how big I make the sub panel I will still only have one 20 amp circuit feeding the shop......or should I plan on two?

Jeff

 

[Anonymous Poster]

I'm just a simple dirt farmer, so _please_ don't rely on my comments for a wiring project. However, I've been following this thread, and have the following observations:

I think I read once that the inspectors don't like 2 seperate runs from a main box to the same place - leaving the old 30 amp run and now adding a new 60, 100, or 20 amp run may be frowned upon? Not sure on this, might be perfectly fine on an upgrade?

And, you can't run a shop on 20 amps. You need 60 amps there all by itself. Any single good-sized power tool will pull most of the 20 amps on it's own at start-up. you will be living with constantly dimming lights. You want the lights on one 15-20 amp circut, and some plug-ins on another circut, and perhaps room for a heavier circut, like your air compresser or a welder.

This might be a bit of overkill if you have a real small shop, but 1 20 amp circut just won't do it. As long as you are installing, go for more now - you'll be happy.

--->Paul

 

[kyoders]

Jeff,

It depends on what you are doing, but real dust collectors are very handy very often. I have a Bosch R/O sander that can be attached to a shop vac/dust collector. The shop vac is worthless, not enough air flow. If I hook it up to my 300CFM dust collector, it's nearly dust-free. And the dust collector has an induction motor, so it's a whole lot quieter. Anyway, you can go anywhere from a low-end, 200-300CFM machine, which typically has a 1HP motor (10-13 amps at 120V, depending on who wrote the specs), all the way up to as big as you want, just about. I'm looking at getting a 2-3HP unit in the near future. I wired my shop assuming I would use my two biggest consumers at once, like a big compressor (one of these days), and the bigger dust collector. Add some for lights, and I would agree that 50-60 amps is a pretty good place to start for a one-person shop.

Kevin

 

[Jeff396]

It sounds like I can't go wrong with the 100 amp sub panel. I guess I might just as well plan on moving the compressor circuit down too. I don't really have the needs currently for my shop that y'all describe, but my wife has expressed an interest in getting into some woodworking. When I mentioned that I would like to get a tablesaw she was quite excited. I look at this as an OPPORTUNITY for more stuff. Hey, how about a pto driven dust collector? /forums/images/graemlins/smile.gif

Jeff

 

[Hoeman00]

I've got a Lincoln Idealarc 250 welder w/ wire feeder and just normal welding w/ .035 wire and after a while it trips SqD 50 amp breaker ( I replace when it starts tripping often).
I have 200amp service to house and shop.
My 5HP air comp (industrial rating) pulls 23 amps, the new 5 or 6HP compressors are over rated on HP but the low amp draw tells the real story.
I put a 60amp sub in the attached house garage so I could put in a 50amp 220v plug just in case I need to do something .
I wouldn't go under 100amp for a work shop.
If money is concern SqD has a cheap 100amp box w/o main and has 6 or 8 spaces and 100 amp aluminum wire is cheaper than 60 amp copper.

 

[Jeff396]

I did see the aluminum 2-2-2-4 wire for about .85 cents a foot but have yet to price 2-3 romex with ground in copper. From what you say I might be shocked as I need about 50 feet. It sounds as if my best bet would be to install the 100 amp sub and increase the size of the outlet for my compressor to around 50 amps so I will have one plug for those possible 220 high draw items. That in addition to two 20 amp circuits for the shop should do it. That's four spots in the sub already and then there's the rest of the basement too.

Jeff