GFCI advice

[Jon Snider]

As I’ve noted in other threads, I’m in planning stage for building a new shop. It will be a detached building next to, but separate from, the garage.

An electrician will be doing the connection to the panel, etc and will be avail for wiring advice, but my son and I will be doing the bulk of the wiring. Both for fun and learning and to save costs. Before starting out I’ll touch base with our local regional building office too. But would appreciate some advice here on what to expect / plan /budget for GFCI circuits.

It’s not clear to me if this qualifies under the “garage” category or not in the NEC. I say this as I have two local friends in other parts of town who were not asked to include GFCI in their detached shops.

If required (or simply desired for safety) are some circuits not included? I’ve read here of those with some leakage being left off o/w they will trip - such as a fridge or garage door opener. Can overhead lights or dedicated 240v lines to individual machines be excluded?

Shop will not have a “garage door”or opener, but will have wide carriage doors. Not sure if this makes it a garage, but it will be wood floors on joists over a crawl space which seems to indicate it’s not.

There will be outside outlets, for use when I roll some tools such as planer or boats I’m building outside, which will definitely be on GFCI.

Thx again for all advice

Jon

[Mike Cutler]

Jon

The application of the code can vary widely based on geographical location, so the answer for the question in say, California, or Connecticut, can be very different than Colorado.No matter where I lived, I would be putting in GFCI's.
The majority of the "code" NEC, is designed to protect and maintain the integrity of the conductor. A GFCI is one of the few items in that code that is directly designed to protect you. Definitely something to consider.
GFCI's can cause problems with sensitive electronics, and ground isolated equipment, but for 99.99999% of the applications they are used in, they appears to the circuit as a passive device and never causes any issues. ( A machine with a speed controller could have an issue with an GFCI, is one instance that comes to mind. )
They're to cheap not to install.

[Jim Becker]

GFCI on your typical 120v 20a circuits in the shop are a good practice even if they are not required by code, IMHO. They are not really needed for lighting circuits (which should be separate from utility circuits) nor are they needed for most machine circuits. The only 240v circuit I have a GFCI on is my MiniSplit because the power terminates to the device outside where there is theoretically "wet". Relative to electronic interference, there are "better" GFCI breakers available that inhibit issues with electronic devices. The one I used with the MiniSplit specifically has this feature. It's less likely you'll have a problem with the general utility circuits in your shop for this kind of thing...just buy good quality GFCI outlets or breakers rather than the less expensive ones. And do note that GFCI devices sometimes have "a lifetime" and one or more may need replacement in the future.

[John K Jordan]

Some VFC/inverters on variable speed lathes will trip a GFCI every time. I initially installed GFCIs on every 20A 120v circuit in my shop but had to remove one to get a lathe to work. I assume by "local regional building office" you mean you will ask the electrical inspector, often the best thing to do especially if it needs to be inspected.

[Jim Becker]

John, wouldn't that be a situation where installing a dedicated circuit for the lathe (machine) would have been indicated rather than removing the GCFI protection for the general utility circuit? (Not a criticism...just a question)

[Jon Snider]

GFCI on your typical 120v 20a circuits in the shop are a good practice even if they are not required by code, IMHO. They are not really needed for lighting circuits (which should be separate from utility circuits) nor are they needed for most machine circuits. The only 240v circuit I have a GFCI on is my MiniSplit because the power terminates to the device outside where there is theoretically "wet". Relative to electronic interference, there are "better" GFCI breakers available that inhibit issues with electronic devices. The one I used with the MiniSplit specifically has this feature. It's less likely you'll have a problem with the general utility circuits in your shop for this kind of thing...just buy good quality GFCI outlets or breakers rather than the less expensive ones. And do note that GFCI devices sometimes have "a lifetime" and one or more may need replacement in the future.

Thanks Jim and Mike. Good advice. In theory, (hopefully) nothing in my shop will be in a “wet” environment

Nor do I plan to have a sink, bathroom, water or sewer.

I’m certainly not opposed to spending for good supplies nor for safety. My question mainly comes from the experience we’ve had in our house (not wired by me) where we’ve had nothing but trouble with the GFCI circuits in the garage and main bathroom, where we can’t run a hair dryer or plug in a small compressor w/o tripping the circuit. It may be poor design or bad electronics.

I’ll have at least 3 20A circuits for various outlets for hand power tools, etc. On one will be a charging station for my ever growing collection of Makita and DeWalt chargers.

Jon

[Thomas Crawford]

Jon -

I'm currently building a detached shop as well.

Here is what I'm doing:

120/20A general circuits (including mini-fridge and water heater) - all GFCI breakers ~$40/ea
240/20A - normal breaker
lighting - normal breaker

I'm also using all Square D QO components for panel and breakers, highly rated. Hoping that minimizes any random trips.

[Mike Henderson]

I'm a big proponent of GFCI. I would definitely install them - the cost isn't that bad because you can daisy chain outlets off of one GFCI at the head end. They can save lives. And even if they don't save your life, they can save you from an unpleasant shock. I'd touched live wires by accident and the GFCI tripped so quickly that I never felt a thing.

I only had one problem with a variable speed scroll saw motor tripping the GFCI (an old GFCI) and I replaced it with a new one and the scroll saw does not trip that one. Think of the cost of installing GFCI as a form of insurance where you only have to make one payment on the insurance and you're protected for life.

Mike

[Ken Fitzgerald]

I have a GFCI installed on each of the 4 - 120 vac circuits in my shop. I have had no problems what so ever with any equipment tripping them unnecessarily nor have I had any equipment problems caused by the GFCIs. I had a Jet VS lathe on them for several years and have a VS Excalibur scroll saw on them. I am a proponent of GFCIs.

[Jon Snider]

I assume by "local regional building office" you mean you will ask the electrical inspector, often the best thing to do especially if it needs to be inspected.

Yes, definitely.

[Lyndon Klassen]

I have exactly zero GFCI protected circuits in my garage.
Remember there was a time when GFCI protection did not exist.

[John K Jordan]

John, wouldn't that be a situation where installing a dedicated circuit for the lathe (machine) would have been indicated rather than removing the GCFI protection for the general utility circuit? (Not a criticism...just a question)

Yes, which it was (almost): a dedicated circuit, but to two lathes. Later I moved the PM3520b in and ran a dedicated 240v outlet for it so there is just one 120v lathe on the circuit.

I should have expected a problem with the GFCI since I had the same problem with the same lathe in the garage shop before I built the new shop, but I forgot. (Hey, I'm elderly and feeble minded!)

JKJ

[Mike Henderson]

I have exactly zero GFCI protected circuits in my garage.
Remember there was a time when GFCI protection did not exist.

I remember that time, also - I'm old. I also remember, back then, a guy in the neighborhood who was killed when his drill (the old ones with the metal cases) shorted out.

I also remember when polio was common and summer was dreaded because polio cases spiked. It's a poor reason to not get a polio immunization because there was a time when it wasn't available. Same thing with GFCI - it's a poor reason to not use them just because there was a time when they weren't available.

Mike

[John K Jordan]

I remember that time, also - I'm old. I also remember, back then, a guy in the neighborhood who was killed when...

I'm probably older than Mike. When I was a kid in the early 50's none of the automobiles had seat belts. Air bags were not invented. Lots of heads went through windshields.

I don't keep up with the electrical code and the laws, but I think "legacy" installations don't have to be upgraded unless new wiring is installed and is inspected or as required when the building is sold. Doesn't mean GFCIs can not or should not be installed. I put them in my house in the garage, bathrooms, kitchen, and on outside outlets, in the shop on everything except lights and the lathe mentioned earlier. They are quick and easy to install and not too expensive.

JKJ

[Tim M Tuttle]

When I wired up my shop I put GFCIs on all the 120 circuits. You only need to put them at the beginning of the circuit and they will protect anything downstream. I have five 120v circuits in my shop so I only have 5 GFCIs but I have probably 20 total outlets.