Mark Gunther Posted November 24, 2014 Report Share Posted November 24, 2014 Hi all, After multiple forum posts on the issue, then settling, then getting new information on it, I'm once again dumbfounded on how to run power to my shop. Quickfire stats: Running ~70ft cable direct buried from 200A panel to 100A subpanel in a detached shop (300sqft). No pipes/wires in between the two structures. Using #2 Aluminum, so putting in a 90A (or 100A?) breaker in the panel back up at the house. Interior shop wiring features multiple 120V and 240V circuits. I'm quite future proofed and have wired for the following: dedicated circuit for dust collection, dedicated circuit for air compressor, multiple outlets pigtailed and dotted around just in case - tools hooked up to these would never be used at the same time. So the question: 2-2-4 aluminum, or 2-2-2-4? I believe I understand that quadplex is the 'correct' way, but this work is not being inspected. I want it to work, and don't want to kill myself and/or others, but I really need some pragmatic advice here - not just "do it by the code" - because my electrician says 2-2-4 will suffice. I need to know if he's saying that because he's been there done that and it's good enough, or because he's a cowboy who wants to use what Home Depot sell 20 minutes away. Thanks all Quote Link to comment Share on other sites More sharing options...
wdwerker Posted November 24, 2014 Report Share Posted November 24, 2014 The entrance cable to my house is 3 wire. Quote Link to comment Share on other sites More sharing options...
TerryMcK Posted November 24, 2014 Report Share Posted November 24, 2014 Mark get a second opinion from another electrician. You don't want to get electricity wrong. You can't see it, smell it or feel it until it gives you a belt. It's not worth risking it. That way you'll know whether the first electrician is firing from the hip or not. 1 Quote Link to comment Share on other sites More sharing options...
wtnhighlander Posted November 24, 2014 Report Share Posted November 24, 2014 The 'do it to code' advice will save your butt on insurance and on doing it over if you sell your home or have a pro do any renovation that uncovers the 'not to code' work. Quote Link to comment Share on other sites More sharing options...
Mark Gunther Posted November 24, 2014 Author Report Share Posted November 24, 2014 OK, so if I go with 4 wire, does it change what outlets I use inside the shop? I'm not familiar with GFCI outlets.. are they a must or an option? They're pretty expensive! Quote Link to comment Share on other sites More sharing options...
Trip Posted November 24, 2014 Report Share Posted November 24, 2014 The NEC is there to keep you safe... Stating up-front that you don't want an inspection is a real red flag... If there's a fire or you go to sell the house there's going to be a problem... The second red flag is asking about 3 or 4 wire pulls... It's unlikely you'll earth/bond the outbuilding correctly by surfing the net... Wonky grounds will shorten the life of your tools... Electrics are the wrong area to save money on a shop build... Yes, it'll cost some $$ to hire a pro... But it can save $$ in the long run... I'd hire the pro to pull the permit, run the feeder, set the panel, bond everything and get the inspections... From there, you can do the branches. A pro can work with you to manage costs and they can get kit much cheaper than you can... Remember, not all electricians are evil bastards... The jury is still out on plumbers I'll give some input, but I'm going from memory and my last interaction with the NEC was quite some time ago..... YMMV You need ground rods in the outbuilding -- I believe two are now required... The NEC addresses both three and four wire installs... Most municipalities require 4-wire pulls... NEC doesn't require GCFI, but many municipalities require it... The sub's earthing and neutral busses are isolated... My first piece of advice is to get a pro... My second piece of advice is to get a pro.. Good luck. Quote Link to comment Share on other sites More sharing options...
estesbubba Posted November 24, 2014 Report Share Posted November 24, 2014 I know it can be a PITA, but get a permit and get it inspected. Like others have said, it could save your butt on an insurance claim, or even save your life. I got building, electrical, and HVAC permits for my building, and have inspection passed stickers on my panel door and records with the county. Quote Link to comment Share on other sites More sharing options...
wdwerker Posted November 24, 2014 Report Share Posted November 24, 2014 So I guess my house is old and grandfathered . My shop is in a commercial building and there is 3 phase available so can't use it as an example. As slippery as insurance companies are these days you know they are going to blame anything done off permit or not up to code and refuse to pay. So I throw my vote with the rest, get a licencend pro and do it up to code. Quote Link to comment Share on other sites More sharing options...
..Kev Posted November 24, 2014 Report Share Posted November 24, 2014 OK, so if I go with 4 wire, does it change what outlets I use inside the shop? I'm not familiar with GFCI outlets.. are they a must or an option? They're pretty expensive! No, it doesn't change your outlets in the shop. Yes, GFCIs are expensive but, you don't need them at every outlet. Suggest dropping one on each circuit except maybe the lighting which should be on its own circuit. It should be the first one off the box on each circuit. And, to echo those above, get the permit and inspection. You can do the work yourself but, it could save your bacon in the long run. The electrical permit and inspection for my 30 x 50 building was only about 80 bucks. Also, Trip is spot on with the grounding. Where I'm at, 2 rods are required. Quote Link to comment Share on other sites More sharing options...
Trip Posted November 24, 2014 Report Share Posted November 24, 2014 ==>Yes, GFCIs are expensive but, you don't need them at every outlet It's in areas like this is where my NEC knowledge gets thin and rather dated... Last go-around, used GCFI breakers on utility branches... not sure that's still code... Also installed panel-based overload and spike protection... Not sure if that's still code either... ==>Where I'm at, 2 rods are required. Someone will have to chime in, but at some point you could use facility water as one of the ground bars... I think that may have changed... My last service work was around '09? and we could use city water plus one bar. Local rqmts: 4-wire pull, 36" trench+conduit, electric and teleco in seperate conduit, no AL, up-gauge every 130'. I forget the rest... BTW, sometimes 4-wire is a lot cheaper than 3-wire because, depending on gauge, they make a lot more of it... ==>So I guess my house is old and grandfathered Grandfathering only carries you so far... I forget the formula, but there's a threshold of change (and it's pretty low) where electrics need to be brought-up to code... Same goes for structure, insulation, etc -- but the thresholds are higher... This is one area where an electrician can pay for himself... Quote Link to comment Share on other sites More sharing options...
estesbubba Posted November 24, 2014 Report Share Posted November 24, 2014 You can get 3 packs of 20 amp GFCI's for about $30 so not bad. Like TIODS said, put a GFCI as the first outlet on the circuit using the line terminal. You can then use standard outlets downstream using the load terminal. Buy an outlet tester that can also pop GFCI circuits so you can test your downstream connections. Check your local code, but in my area 220 circuits don't need to be GFCI protected. Quote Link to comment Share on other sites More sharing options...
Tom King Posted November 25, 2014 Report Share Posted November 25, 2014 Find another electrician. It's foolish not to do it to code. Quote Link to comment Share on other sites More sharing options...
Beerboss Posted November 26, 2014 Report Share Posted November 26, 2014 The difference between the two is the neutral. You have triplex going to a house as a first point. The neutral is bonded to the ground making it a grounded current carrying conductor. One you leave the main point you must "float" the neutral. The ground and neutral will be separate in your sub panel. You do not bond your ground bar to the cabinet and you do not bond your neutral to the ground. So, secondary distribution panels will have 2 hots, a neutral and a ground. Quote Link to comment Share on other sites More sharing options...
Trip Posted November 26, 2014 Report Share Posted November 26, 2014 ==>One you leave the main point you must "float" the neutral A bit off-topic.. what happens if your service disconnect and main panel are separate? As was the case with my last service upgrade... I know what my installer did, but have aways wondered... Quote Link to comment Share on other sites More sharing options...
Tom King Posted November 26, 2014 Report Share Posted November 26, 2014 Code calls for four conductors to a sub-panel. Neutral and ground are not connected in the sub-panel, as Beerboss said-no bonding strap to box. Ground rod/rods at the outbuilding, may or may not be required by the local inspector, but usually are. I'd put them in anyway. A separate main disconnect from the main panel is required when the main panel is not right on the inside of the wall behind the meter. It's mostly a safety thing for the local fire department, so they can turn the power going into the building off quickly. If there is a disconnect beside the meter, they know not to go looking for it inside the building. Even if you are doing all the work yourself, I'd still permit it, and have it inspected. It will be a good thing if you, or yours, ever decide to sell the place. 1 Quote Link to comment Share on other sites More sharing options...
Beerboss Posted November 26, 2014 Report Share Posted November 26, 2014 Tom's right, get a permit. Most...not all...inspectors will work with you if you show you are trying to do the right thing. I would approach it as asking for an education. These folks, like most people like to show you what they know if you ask them right. Most people don't understand the amount of damage a neutral can do. Many assume it is another ground. Trust me, it IS a current carrying conductor! You do not want to get between it and ground if it is under load. Quote Link to comment Share on other sites More sharing options...
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