[OP]
Member
Is there a good source on the Internet or where ever to explain what the capabilities of my current electrical set up might be? I have an outbuilding with a sub panel it looks like it has additional capacity but I want to make sure of that before I do anything.
I read a book from Black & Decker on electricity but it really didn't explain how to figure out what your current system might be capable of or how to modify it.
Thanks
Contributor
Anthony,
I would think about hiring an electrician for an hour and have him or her look over your set up. If you decide to do this, do some serious thinking about what you'd like to do in the future. Write down questions prior to them arriving and take notes of what they say and recommend about your system.
This would be the safest and maybe the most expedient method of getting a determination of what your system is capable of handling.
Ken
So much to learn, so little time.....
Contributor
The first thing you need to do is determine what size wire you have going to your building. You will also need to know if it is copper or aluminum.
Let us know what you have.......
Army Veteran 1968 - 1970
I Support the Second Amendment of the US Constitution
[OP]
Member
It is copper but I am not sure what size. The main breaker for the sub panel is 60 amps....
Member
Currently going through identical situation (detached garage with existing subpanel).
If you have some understanding of electrical things, I found Wiring Simplified (author Richter et al) was a good intermediate book to better understand your current set-up and the requirements for expansion. It explains all the code/practical requirements for expansion/upgrade.
The "picture" books, as you found out, are great for circuits and technique 101, but steer away from big or advanced topics.
I also read (and reread) many of the key posts from this forum. They are an invaluable source of shop specific know-how that complements the general nature of any book.
That said, I had an electrician out yesterday (1 hr fee) to take a close look, size up the current situation and make suggestions on my proposed plan. He made some very helpful suggestions -- and most importantly -- gave me confidence in the overall situation.
Glad to provide add'l info if needed.
Good luck.
Ken
[OP]
Member
How many amps is your subpanel?
Thanks
Originally Posted by Ken Cohen
Contributor
Anthony, you have a 60 ampere feed to your subpanel.
What equipment do you have in your outbuilding, and what equipment do you want to add?
Are you a hobby shop user, one machine at a time running or do you intend to run multiple machines at once?
regards, Rod.
Contributor
do the electric meter tell the max. amperes ?
Member
I'm lucky. My subpanel is 100 amps -- put in 40 years ago by prior owner.
Watching my electrician, he estimated size three ways:
1. Size/make of panel -- approximate size
2. AWG of incoming wiring -- closer guess
3. Breaker size at main box -- definitive
[OP]
Member
I guess I could have asked this in a simpler way....
The main breaker on the sub panel in my shop is 60 amps. How can I tell what the capacity is? Can I add more receptacles or lights? Possibly even a 220? Without running more wire from the house to the shop?
Or is it impossible to tell without looking at it?
Thanks
Member
I'm not an electrician and don't play one on TV, nor did I stay at a Holiday Inn Express last night. That being said, your "capacity" is 60amps running at a given time. How many and what size breakers are currently in the panel? 60 amps is generally regarded as enough for a one man shop, as you would not likely have anything running simultaneously that would exceed that. The exception might be with a large dust collector running with a high HP machine and then the air compressor kicks on. Otherwise it depends on what you want to run on a given circuit at one time. 220 will actually require less amperage (1/2) for a given tool, but will require a 20 or 30 amp breaker generally, depending on the draw of the machine. So it depends on the breakers in the panel and the circuits, etc.
Member
As to whether you can have 220 V out there, you need to see how many wires are going out there now. If you only have two wires and a bare ground wire, you only have 120 V out there and would need to run another wire to carry the other leg needed for 220 V and also change the circuit breaker in the main panel to a 220 V ganged circuit breaker. If you also have an electric heater, that is a real current hog and will probably take half of your 60 amps. Other heat would be much more desirable in this case.
As to the capacity, you just have to add up the amp requirements for everything that you might want to be running at the same time, (as an example, a saw, dust collector & lights), then be sure they don't add up to more than 60 Amps. Look on each tool's motor plate for FLA, (Full Load Amps), then you also have to figure how many lights you will have on to figure how many amps they will require.
Last edited by Norman Hitt; 12-13-2010 at 5:17 AM.
"Some Mistakes provide Too many Learning Opportunities to Make only Once".
Member
I've been a electrician for 25 years and would really like to help you with any questions you may have. Normally you would only be able to have 80% of that 60 amp. . But 60 amps is quite enough for a small shop not running a ton of machines at once which is doubtful but still should be considered. If I can't answer your question I will look it up and get back with you. As we all know it's not a thing to be played with or guessed at. I look forward to hearing from you soon. Darrell Ford
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