After looking at some recent threads, I would like to voice my opinions as to just how you should wire your shop- be it a converted garage, or a purpose-built structure.
Too often, I see avid hobbyists who have all the latest gizmos- but completely inadequate utilities, including the electric. Even worse is when someone has, over the years, employed any number of ‘clever tricks’ to hobble along.
As I see it, the first thing you need in your shop is enough lights and receptacles, in the right places, to do what you want to be doing.
Receptacles over and under benches. Drop cords over machines. Lights, lights, and more lights.
You also need to heat, cool, and ventilate your shop.
Control is important. There’s no sense in lighting up every bench if you’re only working at one. Nor should you ever have to walk completely across your shop to get to the light switch.
Also there is the very important safety consideration of machines starting up all by themselves. Every machine that can operate without you actually holding a switch (trigger) down should be on a magnetic starter- that way, a moment’s power interruption won’t result in the thing starting automatically when power is restored.
Indeed, every fixed machine should be on a circuit sized for it. If there are several machines, of similar requirements, but not likely to be used at the same time, you may feed them from the same circuit. If they are different…say, one requires 12 amps and another 20….they don’t belong on the same circuit. I prefer separate circuits anyway, so that you may shut the cirvcuit off for maintenance- without also downing the other machine.
With the number of machines, and differing requirements they all have, you are best served if the shop has its’ own separate electrical panel. Locate it at the shop. With the panel there, adding circuits is a snap.
I reccommend running the wires in EMT (lightweight steel tubing), exposed on the surface of the walls and ceiling. This arrangement will make it much easier to make any changes later.
If you need a circuit, run a new one. Clever tricks…..one guy has posted here about getting 110 from a 220 circuit….open the door to all sorts of problems. There are many, many examples of such ‘creative’ methods either resulting in fires, or in equipment not operating properly. As soon as the wiring is cleaned up, the problems disappear.
If I were to suggest assembling furniture with drywall screws, this forum would explode with cries of “butcher!” Please do not let some fool ‘butcher’ your electric work!
Replies
nice post, .......simple common sense.
hopefully this won't turn into a shouting match with some folks here waving the NEC to start an argument over something they infer !
I agree with your post, and would just add that unless you are a qualified electrician, it makes sense to have your work permitted and inspected by the city. If they'll review your plans in advance, it might save you money and trouble, too.
Very good post!! I will share my bit of knowledge, I worked in a shop for years that was wired by some inexperienced guy that wanted to save some money and do it himself (me) and while I didn't burn the place down, I did have some interesting things going on for a long while. It was basically right, but there were grounding issues and load issues that should have been done differently. Now I am finishing a new shop, and found that with some guidance and talking to inspectors I could once again do the job myself, but this time do it right and with the good graces of the local building codes folks. They will help you out with all kinds of information if you approach them with the idea of wanting it done right. When I had my shop inspected they were impressed with how well it was done and the fact that there were no codes broken. It was wired properly all the way from the panel it comes from to the shop panel and to the lights and outlets. It can be done right, and with the good graces from the inspectors too!!
john, i just want to say that i like your "goal", and wish all proffessional woodworkers and contractors felt the same way! as a contractor of twenty years experience, i've always believed that quality and craftsmanship are synonamous, and have told employees at times to redo something because "we do better work than that".
Thanks for the post, I hope that some "cheap charlie" got your message, might save his house or life. I did big corp facilities for 30+ years as the suit that hires the architect/eng/subs . Now I have to do my retirement shop in east TN. The house has a 200 amp service, it's all electric-heat pump/hot water/stove/dryer- I will dump the stove (can't cook a good pasta sauce on an electric and a bechemel, a reduction or brown gravy is out of the question) add a gas hot water heater and keep the rest as the electric rate is great. The basement already has several 220 lines that I will reconfigure but I plan to contract a 100 amp sub panel to feed most of the shop. I see 2 dedicated 220 circuits, many bench utility or small machine circuits and lighting . I plan a quad per bench, split over two circuits and alternating non-serial use for the smaller machines. Lighting is 12ga. all other 110 is 10 ga.-breaker amps according to usage(20/20+/slo blow).
My question is am I better off pulling loose wire to the sub panel or using romex of equal gauge? It all goes in surface mounted EMT and I will do all the bull work, then engage a qualified local electrician to balance and tie in? I expect that I will chat with a few before the correct one shows up. thanks, Pat
i am pleased that my post has pointed some folks into the right direction- planning before having to 'improvise!' Romex in pipe is a subject of some debate....code arguments aside, I believe that it is a mistake; by doing so you manage to negate the advantages of both- Romex and EMT! Romex was developed as a quick, easy way to run a handful of simple circuits in a home. At the time of its' introduction (during the Great Depression), many homes had but two circuits, on a 30 amp service!
A workshop is another thing all together. Within that pipe may be wires of different sizes; you may wish to use different color wires to help keep things straight, and there will be 'control' wires as well. For example, many shops have a system that automatically starts the dust collector whenever a machine is used. When you use pipe, you can have an almost unlimited variety of wires within a pipe; Romex limits you to what's in the jacket. As far as feeding the shop panel is concerned, you may be able to use "SE", or 'service entrance,' cable. This stuff looks like Romex, and is probably what you are thinking about. This is also an area where local codes very often require that the feeders be run in pipe. Even if nothing else in the house is in pipe, I prefer to run feeders in pipe, as I want to afford lots of protection to those big wires.
I will visit the new Tn. house late in Mar. and it's now time for me to check out their codes, I expect that my perspectives will exceed their codes, thanks for the input.Pat
I believe a sub-panel always requires the ground to be bonded back to the main panel. I don't think true SEC has a ground, but maybe they make one for sub-panels with a ground.
Bryan, for all I know, you may be right about SE. As for the "sub" panel needing a ground wire, you are absolutely correct.
According to my inspector, where I live you can't run Romex in conduit for any long length (heat), but he let me run two 110/15A through a single 5' length of conduit just to protect them from the ceiling to the 4' high outlet. Same for two 220/30A circuits, for which I ran two 10/2+ground through a single pipe into a metal box, one circuit ending in a NEMA receptacle, the other circuit passing out through the knockout into an attached second box for the second receptacle.
He preferred this solution to switching to EMT at a junction box in the ceiling, because the conduit is even more damage resistant than the EMT in this surface mounted (on a wooden structural post) application in a shop area. It may make a difference that this is in a residential garage -- in a commercial setting I wouldn't be surprised if he refused to allow the Romex in conduit.
Everywhere else in the shop, I ran Romex behind drywall, so no need for EMT or conduit.My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.
uh ... what is the problem with drywall screws in furniture?
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