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Thread: Any help for my discussion with the inspector?

  1. #1

    Any help for my discussion with the inspector?

    Help, !! Just thought of a question that I need some advice on prior to my next 'go-around" with the inspector. My dewalt 735 states it is 15amps @ 120v. According to the concept of 80% max load, that would mean I have to wire a 12/2 circuit 20amp breaker to accomodate this machine. Seems insane as it runs just fine up until now, and has been run on just a 15amp regular garage circuit up until now even using a 25 foot 12G extension cord as well. I'm now "officially wiring my woodshop (garage) and am having it inspected for insurance urposes. I believe in doing it the right way, but man, this dedicated single circuit plu and circuit stuff seems like overkill. Do all shop machines on 120v that are 12+ amps HAVE to be on a seperate dedicated 20 amp circuit? This shop rewire is making my head spin!

  2. #2
    You're overthinking this. The NEC 80% recommendation applies to continuous loads (which is 3 hours or more at the maximum current, Article 100 I believe if the inspector is a jerk). If it's 120V and required a 20A circuit the machine would have a NEMA 5-20 plug or similar so that you couldn't accidentally plug it into a 15A outlet.

    You probably want to use 12AWG anyway so that you don't have to re-pull wiring if you ever do want a larger 240V circuit or whatever but it doesn't need to be dedicated unless you are trying to avoid the GFI requirement for 120V circuits in garages (which you really shouldn't be).

  3. #3
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    I would also go with 12AWG wire and 20A breakers and use 15A or 20A outlets as needed. If the tool came with a regular 15A plug then you can use a regular 15A outlet and so a 15A or 20A circuit would be fine as well. If in doubt about the inspection just tuck the planer away and don't volunteer that you are concerned about it. You should be fine even if the tool is pluged in for the inspection.

  4. #4
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    If the inspector isn't a pompous jerk, how about asking? "Sir/Ma'am, I'm thinking about running a 15 amp portable planer intermittently. What size circuit do I need? When do I need dedicated circuits?" That might provide a clue about how he/she thinks. I think Harry has it right about the 80% rule.
    Last edited by Curt Harms; 03-14-2012 at 7:30 AM.

  5. #5
    I've never seen an inspector care about what you're going to plug into 15 or 20A circuits. If this is a garage (at or below grade), they're going to want to see GFCI. They shouldn't give a hoot what you may plug into it.

    The code and the industry (UL) approval for the tool already covers the issue past that as already mentioned. If the thing came with a 15A plug on it, it can be plugged into a 15A receptacle. It's always possible to overload a branch circuit that has more than one receptacle on it, the code and the OCD take care of this.

  6. #6
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    I concur for the small difference in price versus the potential cost for reworking the wiring later or having problems, run 12 AWG wire everywhere. Also use 20 amp breakers in your box to avoid nuisance trips. As long as you are a one man shop you will never have two machines running on the same circuit at the same time. The 20 amp capability will save you if you happen to have a friend over to help with a project and you do need to run two tools at once or you decide to up grade to a bigger better saw/planer/jointer/shaper/etc in the future.

    You shouldn't need a dedicated circuit for plug in equipment.
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  7. #7
    Here in Ohio, all 120v power circuits MUST be on arc fault CB's.....I ran into that when I rewired my house and added a 60 amp panel in the garage.....really annoyed me and they also required those pita tamper proof outlets....what a monumental waste........

  8. #8
    thx for the input. (calmed down now), I think your right, just run a bunch of 12/2 and let it go. My Grizz 490 says it has a 3hp and takes 18 amps. So therefore, it now has to go to a 30amp plug & 10G wire. Being as it is a new shop & set-up, I'd hoped to run a bunch of 20amp plugs around various areas just in case I need to move stuff as I figure out work pattern traffic etc. Seems the inspector in my area wants to see (if you have them on site) ... and although I'd like to just have them out of sight, I am not able to drag 400lb machines up a gravel driveway ! (can you imagine?) the machines and then see which plug is "dedicated" to that machine. Doesn't offer me much opportunity to move stuff around. Good idea to just "up the guage" so that should I need to, I can change plus & breakers to allow a little flex on placement.

  9. #9
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    Quote Originally Posted by Scott Driemel View Post
    thx for the input. (calmed down now), I think your right, just run a bunch of 12/2 and let it go. My Grizz 490 says it has a 3hp and takes 18 amps. So therefore, it now has to go to a 30amp plug & 10G wire. Being as it is a new shop & set-up, I'd hoped to run a bunch of 20amp plugs around various areas just in case I need to move stuff as I figure out work pattern traffic etc. Seems the inspector in my area wants to see (if you have them on site) ... and although I'd like to just have them out of sight, I am not able to drag 400lb machines up a gravel driveway ! (can you imagine?) the machines and then see which plug is "dedicated" to that machine. Doesn't offer me much opportunity to move stuff around. Good idea to just "up the guage" so that should I need to, I can change plus & breakers to allow a little flex on placement.
    I may be dense but why do you need 10 ga. wire & a 30 amp circuit for an 18 amp load? Remember, the 80% rule only applies to continuous loads, maybe something like a water heater or electric heater where the device could draw rated amperage for 3 hours continuously. I doubt a jointer is going to be running boards end to end for 3 hours at max depth cut. I don't see anything wrong with using 10 ga. if you want but #10 romex can be a pain in the posterior to work with.

  10. #10
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    Do you have an electrician as a friend you can run this by and who may know the inspector? At least you will know if the inspector is being a pain in the butt because your doing it yourself or is this a requirement in your area. Also, you many get some insight on what you need to say to him code wise if this isn't a requirement.
    Don

  11. #11
    Quote Originally Posted by Scott Driemel View Post
    My Grizz 490 says it has a 3hp and takes 18 amps. So therefore, it now has to go to a 30amp plug & 10G wire.
    No, I don't think that's correct. Grizzly recommends an 20A plug, so that's what you should use, and you can use 12g wire and a 20A breaker.

    I think you (and/or your inspector) are confused about the scope of electrical inspection. I doubt the inspector has any authority over what tools/appliances you plug into anything. If it has a plug and cord, it's not permanently installed, and not subject to inspection. The inspector should check that the wire size, breaker size, and receptacle ratings all match. Once that's done, you should be free to do whatever you want.

  12. #12
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    First, the inspector ain't gonna know what will be plugged into the outlet. Two, you shouldn't have an insurance issue if there is a tragedy since the Dewalt is sold with a 15 amp plug, VERY few if any portable "consumer grade" power tools have a 20 amp plug. When a company makes a true 20 amp tool they lose a lot of their target customers.

    That all said I agree with the rest, use 12/2 and use standard 15 amp duplex outlets. Since it is in a garage the 120v outlets will most likely have to be GFCI protected.
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  13. #13
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    [QUOTE=Scott Driemel;1894186] I'm now "officially wiring my woodshop (garage) and am having it inspected for insurance purposes.

    Scott, Is it commercial or hobby shop? Insurance is a different issue from safe and logical practices.

    From what I can tell by talking to several insurance people, you are covered for any fire that results from hobby use. Even if the wiring is done wrong per code.

    Of course you want it done right to be safe.

  14. #14
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    I believe you are mis-thinking this. The DW735 is a "portable" machine (just don't port it too often without help!) intended to be plugged into an ordinary household branch circuit. The 15A rating says that a 15A circuit should be adequate for it, as does the ordinary 15A plug on the cord. Also, that isn't the normal or continuous run load, it is the maximum when the machine at its limit. If you run it that hard for very long, it will likely overheat and will certainly wear out quickly. So, I agree with the others who have said this should not be any of the inspector's concern. He should verify things like correct match of the breakers vs wire size, GFCI's where required, wiring practices such as stapling and number of conductors in boxes, etc., but I don't think the code says anything about dedicated circuits for portable devices.

    That said, I'd wire with 12AWG and multiple 20A circuits anyway. It's better for the motors if you minimize the drop in the wiring.

  15. #15
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    I know it doesnt always work, but I try to always just approach the inspector up front about these questions. Many of them like the early intervention to get things the way they prefer (they dont really like giving people a hard time - but its their job to keep the town out of liability issues).

    So any way to just call the inspector and ask these questions? (or do you already know he/she is a jerk - in which case no real way around anyway cause they will always find some problem). When I built my shop, I tore out the window framing to do it the way this particular inspector preferred (which I knew my original framing was to code, and from an insulating standpoint better - but I tore it out anyway simply due to inspector preference). Of course, I could have gotten into a big pissing match with him about how I did it was technically correct, but that would have burnt me in other areas.....

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