Ugly’s manuals are time-tested technician-approved. Every electrician should have an Ugly’s manual with them on every job site they’re on, let’s talk about some examples as to why.

Ugly’s is an electrical field-reference book that every electrician should have on their jobs. It has so many useful diagrams, schematics, code articles, terms, math and much more. Rather than lugging around a huge 800-page codebook around with you everywhere, you can keep your Ugly’s book in your tool pouch or in your pocket when you’re on job sites.

Some examples of where you’d use Ugly’s are:



You can use the FLC charts in the NEC, or just pull out your Ugly’s manual. Ugly’s has the FLC charts on single-pages back to back and if you tab the book like I do, they’re easily accessible. Say we have a 208v 3-phase 10-horsepower motor on a job, and we need to figure out the current draw so we can decide what conductors to run to it. We’d open up the 3-phase FLC chart, look up 10HP, move over to the 208v column and find that this motor will draw 30.8-amps. Now we have our current and can start to figure out other factors that the motor may have to size the conductors or overcurrent-protection device.



We can use Ugly’s to size EGC’s as well. We’d simply open the manual to the page labelled “Minimum Size Equipment Grounding Conductors For Grounding Raceway and Equipment.” If we have a 100-amp breaker ahead of the piece of equipment, we look at the column to the left and choose 100-amps. Then we move over to the Copper column, and see that this piece of equipment should have a #8 grounding conductor run to it.



Equipment grounding conductors are the conductors that connect the service to the grounding electrode we’ve installed in the earth. These conductors are sized differently than equipment grounding conductors, as they’re not based on the size of the breaker ahead of a piece of equipment. Grounding-electrodes are not equipment so there’s no breaker ahead of them.

Instead we size the GEC based on the size of the largest UNGROUNDED (current-carrying) conductors entering the enclosure. For example say we have a 200-amp service with 2/0 copper conductors feeding our main service panel. We use that 2/0 copper as our basis for sizing the grounding electrode conductor going down to our ground rod. We look in the GEC table at 2/0 copper, follow it over to the Copper column on the right and see that for this service we need a #4 ground run to it.



Conduit fill is something electricians calculate on a fairly regular basis, regardless if they’re working in residential, commercial, or industrial. Rather than carrying your code-book around just to have these values nearby you can just pull out your Ugly’s (because its in your tool bag nearby right?).

Say we have a 2” EMT conduit that we want to see how many #2 THHN conductors we can fit in it. We open up our Ugly’s book to the page labelled “Maximum Number of Conductors In Electrical Metallic Tubing.” I have my THHN values highlighted because I use them so often, but if you don’t scroll down to the bottom where it says THHN on the left-hand side. We’re working with #2 conductors so find that next to the word THHN. From there we see all the conduit sizes along the top so find 2” and follow it down to the bottom where it meets up with our row for #2 conductors. You should 11 is the answer to how many conductors we can install in that conduit.

side note – we can actually fit more conductors than this, but the code states we need to keep the conduit fill to 40% of the area of the conduit.*


As you can see, it’s extremely useful to have an Ugly’s book nearby. I keep one in my visor, and one in my tool bag that I carry in with me to every job. I leave my NEC codebook out in the truck so when I have more complex issues that can’t be found in the Ugly’s book, I can still use it. Ugly’s has an app as well, if you’d prefer to be a rogue-digitalite like me. I have the NEC app as well, and I use both the Ugly’s and NEC apps more than I use the books. I find that my phone is always in my pocket, so it’s the closest thing to me more often than not. Either way go out and get you an Ugly’s book. For only $12-15 they’re priceless……see what I did there?

Please check out the Electrician U Facebook page and subscribe to the YouTube Channel if you like these videos! Also check out the Electrician U Instagram page.

**Disclaimer – These videos are for training purposes alone, all work done on electrical systems should be done by a licensed and insured electrical contractor.  If you are not an electrician, do not attempt any of the work you are seeing in these videos.**