Introduction and shop wiring Q

[Dan Hahr]

Wade - The 50 amp breaker is used with two separate wire feeds of 10 gauge wire, one powering a 220v 15 amp 15" planer and the other to my 220v 13.7 amp table saw (at least the wiring going to these is 10 gauge). Now that I have done some studying and reading and with the comments here, I see lots of problems in my panel. I should replace the 50 amp breaker with a 30 and a 20. The 30 powering my table saw and DC (1.75hp 220v 7.5 amps) on one circuit with two outlets. The 20 amp dedicated for the planer. I also see I "probably" shouldn't have two wires going to the 50 amp breaker, but that will be fixed with that breaker replaced. I also see the folks who wired the panel combined the common and bare wires on one bar instead of adding a bonding (I think the term is) bar connected by a bare wire back to the main breaker. i also found one 120v 20 amp breaker using 14 gauge wire. (And maybe there are more problems.) If I hadn't started this discussion asking some dumb questions, I never would have found all this. I truly appreciate all the comments. Hopefully I get it fixed before I burn the house down. Randy

Randy,

I'm not sure if I'm the only one reading the above this way, but it seems that you are wanting to replace your double pole 50 A 240V breaker with two breakers (20 and 30). Unless you get a very specialized breaker, you can't do that in your current sub panel. You have no need for any circuit over 30 amps. Unless you are going to run your planer and table saw at the same time, you really don't NEED two 240V circuits at all.

I will say this first: Your best bet is to install a new subpanel with at least 8/16 or better yet, 12 spaces/24 circuits so you have plenty of room to properly wire everything and leave some room for expansion. You could run two 30A circuits for the 240V stuff using 10ga wire which is relatively cheap, and have plenty of capacity.

If you are strapped for cash and want to use what you have, you can FOR THE MOST PART. You need to replace the 50A DP with a 30A DP breaker, ensure the wire running off of it is 10GA throughout the circuit, and daisy chain your 3rd outlet off of the closest receptacle. Running all three at once will probably trip the breaker, as it should. You will have to add a separate ground buss, and bring in another wire to feed the panel with a proper neutral (or a heavy red wire for the second hot leg, which should have been done the first time.)

Either way, you have some serious rewiring to do. I'm not sure you understand it completely yet, but hopefully you will soon. A GOOD electrician, standing next to you, not online, will be able to make it all make sense. I hope this makes sense, several others are basically saying the same thing. If it doesn't, don't try this yourself.

Dan

[Randall J Cox]

Ok, I dug deep into my wallet and I had an electrician over today to take a look at what I had and what I wanted to do. I told him to fix it. He is going to run a new #6 three wire (and ground) from the main panel to separate the commons and grounds in the subpanel. He will change out my 50 amp two pole breaker to two 30 amp two pole breakers (actually a quad), which in turn will end up with only one wire going into each breaker (as opposed the two wires per breaker that I have now). He will also add another 220 outlet. Unfortunately the main breaker panel is 100 feet from my subpanel, opposite ends of the house, that's a lot of 6 gauge cable. When done it will be all be safe. At least my two 220v circuits had 10 gauge wire already, the only thing that seemed to be right. I appreciate the members of this forum spotting all the issues I had. The electrician spotted one more, the small gauge of the bare ground wire that was handling current with all the commons and bare grounds together. Well, I learned a lot from all this. Thanks again, great forum. Randy

[Ben Rivel]

Ouch, 100FT is a long run for tall that copper. So what it all end up costing you if you dont mind telling?

[Marty Tippin]

That's great news, Randy. You'll be happier in the long run, even if it means a few bucks out of your pocket. Sounds like you'll be well prepared for whatever new machines you add to your shop.

[Chris Padilla]

This is money well spent, Randy, and you got an education to boot! Most excellent!

[Steve Meliza]

I'll echo what Dan Hahr said, upsize the sub panel while you're at it which will leave room for future additions. Here is a 12/24 panel that will accept your existing breakers - http://www.homedepot.com/p/Square-D-...25VP/202529821

[Randall J Cox]

That's great news, Randy. You'll be happier in the long run, even if it means a few bucks out of your pocket. Sounds like you'll be well prepared for whatever new machines you add to your shop.

Marty - Although it's tempting to install a bigger panel, I really can't stuff any more machines in my shop. This fix should do me, or any one who buys this place, fine. This will give me two 220v 30 amp circuits and two 120v 20 amp circuits in my small 16x18 shop (not counting the separate 20 amp circuits for lights and garage, outside of my shop, which is where my grinder and air compressor are located). Randy

[Mike Jungers]

You can run feeders in parallel, but they have to be a minimum of 1/0 if I recall, but more importantly that has nothing to do with this situation. If I rolled up on that panel, I'd replace it with a larger main lug panel to get more spaces, un-bond the neutral and ground and install a seperate ground bar, and place the 12-2 romexes on separate 20 amp 2-poles. For your 3hp loads, you need 10 awg wire on 25 amp breakers, or 30 amp breakers if they trip when you start them. Make sure the receptacles for the 240v circuits are rated the same as the breaker used, not higher or lower.

The NEC dictates that every part of a circuit is sized properly to prevent overloading any one part. That 50 amp breaker will let that 12-2 romex get waaaay too hot before tripping. Good on you for asking what to do and not burning your shop down.

I'd welcome you but it's my first post too!

Mike

[Randall J Cox]

You can run feeders in parallel, but they have to be a minimum of 1/0 if I recall, but more importantly that has nothing to do with this situation. If I rolled up on that panel, I'd replace it with a larger main lug panel to get more spaces, un-bond the neutral and ground and install a seperate ground bar, and place the 12-2 romexes on separate 20 amp 2-poles. For your 3hp loads, you need 10 awg wire on 25 amp breakers, or 30 amp breakers if they trip when you start them. Make sure the receptacles for the 240v circuits are rated the same as the breaker used, not higher or lower.

The NEC dictates that every part of a circuit is sized properly to prevent overloading any one part. That 50 amp breaker will let that 12-2 romex get waaaay too hot before tripping. Good on you for asking what to do and not burning your shop down.

I'd welcome you but it's my first post too!

Mike

Mike, first off welcome to the forum, this thread is my first here, it's a great forum for learning. What does your 1/0 mean? I tend to do lots of research before I actually do stuff because I want to understand what and why, it's just who I am. Then I'm usually comfortable with my decision and spending $. Randy

[Randall J Cox]

Well, electricians were here today, pulled 100 ft of new #6 three wire, added a couple of 220 outlets, installing new larger panel tomorrow and changing the 50 amp breaker to two 30 amp breakers for the two 220 circuits. Now have two outlets per 220 circuit. Will now be room for more breakers in larger panel for any future expansion. Thanks to forum members who alerted me to all the problems. Not going to be cheap, but will be safe. Randy

[Chris Padilla]

NOW let's see a picture of that properly-wired panel, Randy!! We can all ooh and aah over it instead of being shocked...literally.

[Randall J Cox]

Here's pic of new larger panel finished and buttoned up. Didn't make any changes on the 120v circuits, it was all involving the 240v side. Went from a single 240v 50 amp breaker to three separate 240v circuits. A 40, 30 and 15 amp. Now have four240v outlets, two outlets on the 30 amp circuit with one each on the other two. The DC and tablesaw will share the 30 amp circuit. The 3 hp 240v 15 amp 15" planer on the 40 amp circuit and the jointer will be on the 15 amp circuit - as soon as I change it over from 120 to 240v (it trips the 120v 20 amp circuit breaker now on startup about half the time, its an 8" 1.5HP Powermatic pulling 17/8.5 amps). As they pulled new #6 three wire, it now has separate bars for common and bare ground wires. And I have a couple of positions left empty. Think I'm good to go for a while. It was another learning experience. Now just have to pay the bill when it arrives!! ha Thanks again to all who commented! Randy




IMG_3648.jpg

[Chris Padilla]

Looks nice...how about a "behind the scenes" shot?

[Mike Jungers]

Sorry Randy I missed your question. 1/0 is a wire size, pronounced "one aught", and totally irrelevant now. I applaud your good judgement to hire the work out and not burn down your house.

Mike

[Marty Tippin]

Now have four240v outlets, two outlets on the 30 amp circuit with one each on the other two. The DC and tablesaw will share the 30 amp circuit. The 3 hp 240v 15 amp 15" planer on the 40 amp circuit and the jointer will be on the 15 amp circuit

You might want to re-think how you're going to use the new outlets - since the DC runs at the same time as each of your other tools, I'd suggest putting it on it's own circuit (the 30A is perfect for that); the other tools can be arranged as you like as you're almost certainly going to use them only one at a time.

Can you confirm the wire gauge that the electrician used for the 30 and 40A 240V circuits? I'm also curious what kind of 240V outlets are on each of those circuits?