Free Resource - Motor Wire and Protection Chart
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Motor Wire and Protection Chart

  
 
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In an effort to provide useful tools, Mike has created a neat chart you can use to size conductors, protection, raceway, and equipment grounding conductors that consider voltage drop.

 

This chart should be excellent to use in offices and on job sites, as well as in training facilities.

 

Click here or on the image to download the chart. Please print it out, give it a go, and give us feedback on its use and how it can be improved.

 

 

 
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Mike Holt Enterprises of Leesburg, Inc. 3604 Parkway Blvd. Suite 3 Leesburg, FL 34748
"... as for me and my house, we will serve the Lord" [Joshua 24:15]
Comments

  • Thanks for the great chart. I did have a question on the row that has a 3 Phase 20 amp motor (460v) Looks like the conductor size is #10 and the EGC is #8 all in a 1/2 inch conduit. Seems like this would be more than 35% fill.

    Mike Koprowski
    January 26 2016, 11:28 am EST

  • Mike this chart is great and handy, thanks. Jerry

    Jerry
    December 13 2015, 6:08 pm EST

  • Mike & Associates--Thank you posting these handy quick reference charts--It's a nice tool to use in the field when you need to keep production up. Keep em' coming!!

    Jerry Electric
    December 11 2015, 4:08 am EST

  • Can you run romex above a drop ceiling in a commercial building in New Hampshire?

    Andy Man....
    December 9 2015, 4:38 pm EST

  • Thanks! I noticed footnote 5b, but didn't see its use. It may also be helpful to have one that gets it all on one page of 11x17.

    robert mcalister
    December 9 2015, 1:59 pm EST

  • Nice table... Maybe add a column next to breaker sizing showing fuse sizing...

    Mike
    December 9 2015, 11:45 am EST

  • Question for 2014 NEC. 480.9E Egress for Battery storage room. Need listed Panic Hardware on door for storage Battery room. The code did not address size of Battery output, for enforcement at plan review. So any size Battery storage cabinet is affected?

    Wayne Elmore
    December 9 2015, 11:04 am EST

  • Charts like these are critical tools to help get the information out of the NEC in an easier to read format for quick references. I have shared this with my MGMT team and will also get to our field electricians. Please keep up the work and make some more. Another motor reference one just like this could be useful but change the short circuit/ground fault protection to a fuse (in an MCC bucket example) instead of breaker. Also be nice to add the motor overload protection to the chart as well. -Thank you

    Jordan Smithback
    December 9 2015, 10:35 am EST

  • Just a thanks for the chart.

    Marty Anderson
    December 9 2015, 8:47 am EST

  • Thank you Mike. This chart is very helpful.

    Ray Holland
    December 9 2015, 8:43 am EST

  • Distance in col 6 should be limited to3% (branch circuit motor - most of the time). 5% is the recommended max. Vd from transformer(source) to motor

    Ed Abad
    December 9 2015, 8:31 am EST

  • The chart indicates the voltage drop is based on 5%. Energy codes require a maximum of a 3% voltage drop on branch circuits.

    DRJulianPE
    December 9 2015, 8:31 am EST

  • Would this chart serve the electrician better if it was made to reflect a 3% voltage drop for the branch circuit rather than 5% which also includes the feeder? Typically this would be a branch circuit for the motor and not a feeder.

    Walter
    December 9 2015, 6:52 am EST

  • Very good at field and Off thank very mach,Make,you good men

    Jorge Franco
    December 8 2015, 9:48 pm EST
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