GFCI protected circuits

Forum for Maintenance and Repair topics. Feel free to ask questions or contribute.

Moderator: admin

garys
Platinum Member
Posts: 1767
Joined: Wed Mar 02, 2011 12:16 am
Location: Bismarck, ND

Re: GFCI protected circuits

Post by garys »

This explanation indicates that the GFCI is not needed on a dust collector, and likely serves no purpose for static electricity. Since I have it on a GFCI, I will leave it that way for now. If I don't get false tripping of the GFCI, I'll leave it this way. If I have problems in the future, I'll simply remove the GFCI.
edma194
Gold Member
Posts: 464
Joined: Fri Jun 19, 2020 4:08 pm

Re: GFCI protected circuits

Post by edma194 »

I tripped a 20 amp AFCI breaker the other day starting up the 510 headstock on the drill press. It was first thing in the morning and it was pretty cold down in the basement, and the speed dial may have been up to D. I flipped the breaker and it was fine. I didn't think the AFCI breaker could make a difference but just saw this section from wikipedia about them:

"AFCIs are designed to protect against fires caused by electrical arc faults. While the sensitivity of the AFCIs helps in the detection of arc faults, these breakers can also indicate false positives by identifying normal circuit behaviors as arc faults. For instance, lightning strikes provide voltage and current profiles that resemble arc faults, and vacuum cleaners and some laser printers trip AFCIs. This nuisance tripping reduces the overall effectiveness of AFCIs. Research into advancements in this area is being pursued."

I do think it was just a sluggish start up the other day, but maybe we have to be keeping an eye out for AFCI problems also. Those things are required in new construction just about everywhere now I think.
Ed from Rhode Island

Mark V 510 with PowerPro headstock, Mark V Greenie with 510 headstock, Mark V 500 in progress
Sawsmith 2000 Ultra, 10ER in progress, 10ER undetermined future
RFGuy
Platinum Member
Posts: 1359
Joined: Mon Dec 31, 2018 8:05 am
Location: a suburb of PHX, AZ

Re: GFCI protected circuits

Post by RFGuy »

Yeah, arc fault protectors are a whole other animal. They have been around for awhile but were seldom used in the past, but it does seem like some regions are mandating them more and more now. I don't know much about them, other than that they exist. What I find curious is that they started requiring them in bedrooms only and have continued to add more and more rooms to the list of required spaces to protect from arc faults (see link below). I don't know the details of how they work but I would suspect that any equipment with induction motors with brushes, in theory, could trip an AFCI breaker. Just depends on the condition of the brushes at any given time. The way I view it is a shop is like a manufacturing floor in a factory. You want to provide electrical power safely to all of the equipment and protect the operators but there are always hazards which is why operators and supervisors have to be diligent to protect human life (and property). GFCI and AFCI's were created to prevent freak accidents and human error in operation, i.e. doing things you shouldn't do. Don't get me wrong, safety devices are needed and welcome in many cases, but they won't protect against everything. A more common risk in a home shop, IMHO, is leaving cordless chargers plugged in 24/7 which can cause fires in the worst case. Unplugging equipment not in use, e.g. putting cordless chargers on a timer or switch to turn off is better use of your time than trying to protect against arcs and ground faults in a shop. Also having the proper rating fire extinguisher in the shop in case of an electrical fire due to an arc condition during operation might be a good idea. Just my opinion.

Of course if you have old equipment that isn't well insulated or properly double insulated like with modern, corded, hand-held power tools then a GFCI is a must, so there are always exceptions...Keep in mind a nuisance trip of an AFCI/GFCI could happen mid operation, e.g. during a saw cut and an accident could happen as a result of being caught off guard by this.

https://homeinspectioninsider.com/commo ... uirements/
📶RF Guy

Mark V 520 (Bought New '98) | 4" jointer | 6" beltsander | 12" planer | bandsaw | router table | speed reducer | univ. tool rest
Porter Cable 12" Compound Miter Saw | Rikon 8" Low Speed Bench Grinder w/CBN wheels | Jessem Clear-Cut TS™ Stock Guides
Festool (Emerald): DF 500 Q | RO 150 FEQ | OF 1400 EQ | TS 55 REQ | CT 26 E
DC3300 | Shopvac w/ClearVue CV06 Mini Cyclone | JDS AirTech 2000 | Sundstrom PAPR | Dylos DC1100 Pro particulate monitor
DLB
Platinum Member
Posts: 722
Joined: Fri Nov 08, 2019 11:24 am
Location: Joshua Texas

Re: GFCI protected circuits

Post by DLB »

garys wrote: Sun Apr 04, 2021 10:05 am This explanation indicates that the GFCI is not needed on a dust collector, and likely serves no purpose for static electricity. Since I have it on a GFCI, I will leave it that way for now. If I don't get false tripping of the GFCI, I'll leave it this way. If I have problems in the future, I'll simply remove the GFCI.
With the latest NEC changes adding unfinished basements to the list of areas requiring GFCI, I suspect that vast majority of our home shops are in areas requiring GFCI. Though many are obviously grandfathered to the requirements in place at the time of construction and/or modification. One would presume that most shop equipment would not cause false tripping, the garage requirement has been in place for a long time (80's IIRC).

I'm favorably impressed that fewer PowerPro users seem to have actually experienced the problems cited by Shopsmith when using the outlet style GFCI. I interpreted the written cautions about it much more negatively. I was just looking for that paper to see how it was worded and can't put my hands on it right now. I had been avoiding those circuits, prevalent in my garage shop, which limits me to one available outlet. I had in mind to add a 230 V circuit for the PowerPro because I thought it would be cheaper than switching to a GFCI CB, but I now see that requirements have changed and the 230V outlet would also have to be protected, adding about $100, or roughly tripling, the material cost for me.

- David
RFGuy
Platinum Member
Posts: 1359
Joined: Mon Dec 31, 2018 8:05 am
Location: a suburb of PHX, AZ

Re: GFCI protected circuits

Post by RFGuy »

DLB wrote: Sun Apr 04, 2021 11:28 am With the latest NEC changes adding unfinished basements to the list of areas requiring GFCI, I suspect that vast majority of our home shops are in areas requiring GFCI.
- David
You have a basement in Texas??? From my understanding they are somewhat common in the MidWest and rare in the rest of the US. Too expensive to dig for them out here, particularly with caliche. I believe garages are far more common today than basements (https://www.basementguides.com/why-are- ... 0houses.).

Always follow the NEC for your local area, but it my understanding that GFCI's are ONLY required for things that plug in, i.e. on receptacles and only in specific locations. Anything permanent wired (on it's own dedicated branch circuit) like a 240V dust collector can be, I believe is exempt from needing a GFCI...but check your local building codes and NEC.
📶RF Guy

Mark V 520 (Bought New '98) | 4" jointer | 6" beltsander | 12" planer | bandsaw | router table | speed reducer | univ. tool rest
Porter Cable 12" Compound Miter Saw | Rikon 8" Low Speed Bench Grinder w/CBN wheels | Jessem Clear-Cut TS™ Stock Guides
Festool (Emerald): DF 500 Q | RO 150 FEQ | OF 1400 EQ | TS 55 REQ | CT 26 E
DC3300 | Shopvac w/ClearVue CV06 Mini Cyclone | JDS AirTech 2000 | Sundstrom PAPR | Dylos DC1100 Pro particulate monitor
edma194
Gold Member
Posts: 464
Joined: Fri Jun 19, 2020 4:08 pm

Re: GFCI protected circuits

Post by edma194 »

RFGuy wrote: Sun Apr 04, 2021 11:40 am You have a basement in Texas??? From my understanding they are somewhat common in the MidWest and rare in the rest of the US. Too expensive to dig for them out here, particularly with caliche.
The majority of houses in the Northeast have basements because the foundation has to be dug out down to the frost line anyway. It doesn't cost that much more to keep digging and make a full basement.
Ed from Rhode Island

Mark V 510 with PowerPro headstock, Mark V Greenie with 510 headstock, Mark V 500 in progress
Sawsmith 2000 Ultra, 10ER in progress, 10ER undetermined future
RFGuy
Platinum Member
Posts: 1359
Joined: Mon Dec 31, 2018 8:05 am
Location: a suburb of PHX, AZ

Re: GFCI protected circuits

Post by RFGuy »

edma194 wrote: Sun Apr 04, 2021 12:50 pm The majority of houses in the Northeast have basements because the foundation has to be dug out down to the frost line anyway. It doesn't cost that much more to keep digging and make a full basement.
Did you read the article? That used to be the case, but the trend is, and has been, away from basements. 82 million single family homes in US now have garages (out of 213 million).
📶RF Guy

Mark V 520 (Bought New '98) | 4" jointer | 6" beltsander | 12" planer | bandsaw | router table | speed reducer | univ. tool rest
Porter Cable 12" Compound Miter Saw | Rikon 8" Low Speed Bench Grinder w/CBN wheels | Jessem Clear-Cut TS™ Stock Guides
Festool (Emerald): DF 500 Q | RO 150 FEQ | OF 1400 EQ | TS 55 REQ | CT 26 E
DC3300 | Shopvac w/ClearVue CV06 Mini Cyclone | JDS AirTech 2000 | Sundstrom PAPR | Dylos DC1100 Pro particulate monitor
DLB
Platinum Member
Posts: 722
Joined: Fri Nov 08, 2019 11:24 am
Location: Joshua Texas

Re: GFCI protected circuits

Post by DLB »

RFGuy wrote: Sun Apr 04, 2021 11:40 am You have a basement in Texas???
Um, no. Sorry if that was misleading. My shop is in my garage. What I was trying to say is that most of our shops are either in a garage or basement or other facility that, as of the 2020 NEC revision, require GFCI. The wettest location I've ever used for my shop was a basement though, and it seemed strange to me that at the time GFCI was not required there but it was required in the garage. The GFCI requirements, as well as the AFCI requirements, seem to continuously expand. Perhaps there is a lobby involved.

At least some hard-wired equipment is now included. Specific examples are HVAC and pool pumps. Also a range if it is within 6' of a sink.

- David
edma194
Gold Member
Posts: 464
Joined: Fri Jun 19, 2020 4:08 pm

Re: GFCI protected circuits

Post by edma194 »

RFGuy wrote: Sun Apr 04, 2021 1:12 pm
Did you read the article? That used to be the case, but the trend is, and has been, away from basements. 82 million single family homes in US now have garages (out of 213 million).
I hadn't before, but now that I did I saw this part:

"One of the main reasons why northern buildings often have basements is the depth of the frost line. When you build a home, the foundations need to be below the depth of the frost line. In the north of the country (and particularly in the midwest) this requires deep foundations, thus making a basement far more practical."

They don't mention the northeast in particular but I see no signs that there is a decrease in the number of basements in new construction around here. The difference in price for the amount of space you get is very small once you have to dig down below the frost line. "
Ed from Rhode Island

Mark V 510 with PowerPro headstock, Mark V Greenie with 510 headstock, Mark V 500 in progress
Sawsmith 2000 Ultra, 10ER in progress, 10ER undetermined future
DLB
Platinum Member
Posts: 722
Joined: Fri Nov 08, 2019 11:24 am
Location: Joshua Texas

Re: GFCI protected circuits

Post by DLB »

RFGuy wrote: Sun Apr 04, 2021 1:12 pm 82 million single family homes in US now have garages (out of 213 million).
I'm calling for a fact check on this one, though I see that number out there. Gotta love the internet. 213 million single family homes in the US??? Seems way high. I saw another site that said 95 million. If I had to believe one of those...

- David
Post Reply