Page 2 of 2 FirstFirst 12
Results 16 to 28 of 28

Thread: Yet more VFD questions... Belt sander

  1. #16
    Join Date
    May 2008
    Location
    MA
    Posts
    2,255
    Wow now that is spelling it out for me, love it!

    I can get into something like this for reasonable $ and have a fully inspected and approved install. Cant beat that.

    Next is decision on the GFI/Arc breakers. 30amp seem to be over $100 each (so that puts me at several hundred $). But I have a 60A breaker feeding a sub panel that has 4 220v circuits and 2 110 circuits. Instead of GFI breakers for each circuit, I was hoping I could GFI the single 60A breaker that feeds the entire panel.

    Inspector was worried there might be problems with different circuits messing each other up and not getting the single GFI to work. He was fine with it if I could get it to work, so I have to figure that part out next. I have had issues with GFI in the past on fluorescent lights, but these 220V circuits are all to feed basic woodworking machines so pretty simple. The 110 breakers go to my fridge and dishwasher, but I think I can swap them from the other panel and instead pull something like an outlet circuit that will never be used at the same time.

    Has anyone run multiple 220v machines on a GFI simultaneously?
    Last edited by Carl Beckett; 03-25-2022 at 8:25 PM.

  2. #17
    Join Date
    Aug 2021
    Location
    Redmond, OR
    Posts
    594
    Quote Originally Posted by Carl Beckett View Post
    Wow now that is spelling it out for me, love it!

    I can get into something like this for reasonable $ and have a fully inspected and approved install. Cant beat that.

    Next is decision on the GFI/Arc breakers. 30amp seem to be over $100 each (so that puts me at several hundred $). But I have a 60A breaker feeding a sub panel that has 4 220v circuits and 2 110 circuits. Instead of GFI breakers for each circuit, I was hoping I could GFI the single 60A breaker that feeds the entire panel.

    Inspector was worried there might be problems with different circuits messing each other up and not getting the single GFI to work. He was fine with it if I could get it to work, so I have to figure that part out next. I have had issues with GFI in the past on fluorescent lights, but these 220V circuits are all to feed basic woodworking machines so pretty simple. The 110 breakers go to my fridge and dishwasher, but I think I can swap them from the other panel and instead pull something like an outlet circuit that will never be used at the same time.

    Has anyone run multiple 220v machines on a GFI simultaneously?
    I don't mean to be rude... but you don't learn very fast do you.... LOL!

    I believe this is what you are asking for:

    https://www.ebay.com/sch/i.html?_fro...acat=0&_sop=15

    Or 30amp:
    https://www.ebay.com/itm/14343117906...cAAOSwmexdtOwD

    https://www.ebay.com/itm/13398414621...UAAOSwYI9h1KLO

    https://www.ebay.com/itm/30403431851...oAAOSwCm1gx3d- -I would offer $200 for all 4.

    None of my machines are on GFI's so I can't help you there.
    Last edited by Michael Schuch; 03-25-2022 at 8:39 PM.

  3. #18
    Join Date
    May 2008
    Location
    MA
    Posts
    2,255
    If I go with a single breaker, that primary breaker needs to be both GFI/arc fault protected (as I understand latest code). 60 amp. That covers everything. Else the individual breakers (4 30amp and one 50 amp) need to each be GFI/arc fault type.

    And breakers need to be the same brand as the box they are in (square D in my case), 'possibly' the same series as the box (SqD has different series panels)

    Then the circuit coming out of the RPC can be a standard breaker as I understand it, so that is just about finding a box/breaker combo in the right brand (again they have to be the same). And the smaller the box the better imo.

    It is a lot of hassle to get a RPC hooked up to meet code - in fact I would say a larger deterrant than simply finding the RPC to begin with.

    I also wonder, since everything has to be on GFI/arc fault, if certain VFD's do not behave well with those. No idea.

    (oh, and a side note that was mentioned prior - I believe the refrigerator and dishwasher both need to be on GFI if the outlet for them is within 6ft of the sink - which would be almost all dishwashers)

  4. #19
    Join Date
    Dec 2006
    Location
    Toronto Ontario
    Posts
    11,248
    Quote Originally Posted by Carl Beckett View Post
    The inspector says: need a breaker on the output of the RPC. So that means a box and a 3 phase breaker.

    Its not obvious they make single breaker boxes, and the larger boxes seem quite large and $.

    More homework.

    It is down to adding the breaker or starting over and running single phase all the way to the machine and putting on the VFD (which very well could be more straight forward...)

    All ears on how others have done it.
    Ask about using a fused disconnect switch, much less expensive.

    The switch will need a label on the front that says “Use xxxxxxx fuse or equivalent only”

    Regards, Rod

  5. #20
    Join Date
    May 2008
    Location
    MA
    Posts
    2,255
    Quote Originally Posted by Rod Sheridan View Post
    Ask about using a fused disconnect switch, much less expensive.

    The switch will need a label on the front that says “Use xxxxxxx fuse or equivalent only”

    Regards, Rod
    yes. He didnt like the fuse (I didnt challenge, but had read other places one fuse can go and still have other legs hot - which still seems ok if it protects the wire). But there is a path forward, just a matter of execution at this point.

  6. #21
    Join Date
    May 2008
    Location
    MA
    Posts
    2,255
    Did get the 3phase breaker installed post RPC. That seems adequate now.

    BUT: A question of how to do dual function GF/AF. It is a garage. Regular 110 receptacles need to be GF/AF. Ok, there is a way to do that.

    But the 220V receptacles? Does 2020 code require dual function GF/AF for a 220 circuit? This gets a little bit difficult...

    Has any of you wired a 220V circuit to meet 2020 code? How did you do it?

  7. #22
    Join Date
    May 2008
    Location
    MA
    Posts
    2,255
    We will see what the inspector says. No GF/AF on the 220 circuits, although I have a 60A GFCI breaker I am going to try and put on the entire box. If it behaves it is a good thing to have GF. GF/AF might not be code required for 220V circuits, although the inspector implied they were I dont think he has encountered this situation.

    He did let me leave the pigtail to the converter.

    Fingers crossed this project is in the home stretch. And all properly wired and inspected, which is not all bad.

    IMG_4845.jpg
    Attached Images Attached Images

  8. #23
    Join Date
    Sep 2019
    Location
    Aurora, IL
    Posts
    93
    I haven't checked 2020 code, I was on an older version when I put in a brewing outlet, but at the time, if the outlet has a specific use, and only 1 receptacle on the circuit, it did not need a GFCI. I did anyway because it was for large volumes of water, but still.

    Also, this is in-line with what you would find for an EV charger and I don't see anyone complaining about GFCI requirements there.

    Side note, Bill was correct on the sqrt(3) conversion to go from single phase to 3 phase. One would expect FLA on a 7.5HP motor to be around 22 amps, this would be 38 amps on a single phase breaker, and would require a 50amp breaker to feed if load is "continuous". If the load is not continuous, you could could argue 100% of the rating. If this is not a commercial operation you should be OK...

  9. #24
    Join Date
    May 2008
    Location
    MA
    Posts
    2,255
    Thanks

    I think it is a change in the 2020 code - both GF/AF on all basements garages etc. But I 'believe' that does not apply to 220v circuits.

    The EV outlet is fed by a 50a breaker. Seems ok as you say. (and again may be exempt due to higher voltage)

    But I am not a code expert, we will see....

  10. #25
    Join Date
    May 2008
    Location
    MA
    Posts
    2,255
    Nope- Strike 1

    I tried a 60a GFI to feed the entire subpanel. (inspector says I need GFI on the 220v circuits but not AF). Was hoping I could GFI the entire panel.

    Interesting enough all the 220 equipment works.

    BUT- anything that pulls one leg, which includes some breakers feeding 110 circuits, trips the GFI.

    More research needed.

    I 'might' be able to move some things around so there is ONLY 220V circuits in this box - but I do have an old range I use to cook stuff in the garage - and that trips it (it might be jumpered neutral to ground in the range, I need to check that).

    All the woodworking equipment works on the 220v gfi - I guess that means I could buy a GFI for each 220 circuit and then separate GFI for each 110 circuits - assuming the 110GFI behaves - which I also need AF for those circuits).

    The saga continues. (other than getting GFI compliant everything else is wired and working)
    Last edited by Carl Beckett; 04-30-2022 at 4:34 PM.

  11. #26
    Join Date
    Dec 2006
    Location
    Toronto Ontario
    Posts
    11,248
    Quote Originally Posted by Carl Beckett View Post
    Nope- Strike 1

    I tried a 60a GFI to feed the entire subpanel. (inspector says I need GFI on the 220v circuits but not AF). Was hoping I could GFI the entire panel.

    Interesting enough all the 220 equipment works.

    BUT- anything that pulls one leg, which includes some breakers feeding 110 circuits, trips the GFI.

    More research needed.

    I 'might' be able to move some things around so there is ONLY 220V circuits in this box - but I do have an old range I use to cook stuff in the garage - and that trips it (it might be jumpered neutral to ground in the range, I need to check that).

    All the woodworking equipment works on the 220v gfi - I guess that means I could buy a GFI for each 220 circuit and then separate GFI for each 110 circuits - assuming the 110GFI behaves - which I also need AF for those circuits).

    The saga continues. (other than getting GFI compliant everything else is wired and working)
    Hi Carl, make sure that the neutral bonding screw is removed from the sub panel and that you have the neutral feed through on the main panel GFCI breaker wired properly…Rod

  12. #27
    Join Date
    Sep 2016
    Location
    Modesto, CA, USA
    Posts
    9,885
    Does modern code require a GFCI on a garage freezer or is that exempt? Is the washer still GFCI exempt?
    Bill D

  13. #28
    Join Date
    May 2008
    Location
    MA
    Posts
    2,255
    Quote Originally Posted by Bill Dufour View Post
    Does modern code require a GFCI on a garage freezer or is that exempt? Is the washer still GFCI exempt?
    Bill D
    Double check with your electrician. My understanding of the 2020 code is that ALL 120 circuits require BOTH GF and AF, if they are in a garage or basement or within 6ft of a sink (most dishwashers, some refrigerators). 220 circuits only need GFI.

    It doesnt matter what you plug in. So yep, all those garage freezers and refrigerators need to play well with it (I put in dual function breakers, but you can hybrid the AF and GF elements).

    'Nuisance trips' are not exemptions, so you have to 'figure it out' to eliminate them.

    Unless hard wired - then different guidelines (not sure the details on this since I put sockets on all my circuits).
    Last edited by Carl Beckett; 05-12-2022 at 8:34 AM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •