I am now torquing all circuit breakers, panel terminals, switches, and receptacles per 2017 NEC requirements. Torque for Leviton residential devices is 12 -14 inch pounds, commercial devices 20 inch pounds. I believe Hubble is 9-12 inch lbs for residential devices. Of course follow what is printed on the device, or consult the manufacturer.
I use a torque screwdriver with a range of 5 to 60 inch lbs. which cost about $70. I always return the dial to zero after a torquing session. I find it is much faster to use the torque tool verses a screwdriver and going 1/4 turn past "snug" which is not accurate.
I think the best thing would be devices with Bellville washers on all the device screws.
These only flatten out when you reach the correct torque. Of course the washers would have to be serialized, tested, calibrated, and traceable back to NIST. I don't think a switch or receptacle would have to be more than maybe $20 or $25 which is a small price to pay for safety.
Any body with experience with circuit breakers, Aluminum wire, and torque values? The breaker is rated for Aluminum wire with a torque value. However when using that value, it squishes the wire to the point of almost breaking free. New screwdriver. Called the manufacturer and he said I had the correct inch pounds.
I'll torque a $20k switch gear and a $75k transformer
I refuse to torque a 20 amp circuit breaker. If you can't properly tighten a small breaker, receptacle or switch......
I recommend plumbing as a new career..... you need only to know two things
1)**** rolls down hill
2)dont eat you finger nails on the way home from work
At the last in-service training class we were told how important it was to torque everything. Instructor even passed around a torque screwdriver and a ground bus bar and everyone in class had a chance to use it. The proper torque was set by the instructor and we were also given #12 copper pigtails.
After everyone was completed I asked the instructor to remove the pigtails because I has a suspicion that the torque was to much simply because of job experience.
Every single #12 copper wire was flatten inside the lug almost to the point of breaking.
I also think there is nothing like experience. I only brought up torquing Aluminum wire on a breaker because it is now in the 2017 NEC and the torque screwdriver is a new tool to use. It probably will sit in the truck for now.
Get your local inspector to put it in writing that you do not need to follow the NEC and torque circuit breakers, switches, and receptacles. Then I will listen to you. (but only in your jurisdiction.)
Also, overtightening distorts the threads and can cause loose and arcing connections.
What do you do when torqueing the receptacles to the required amount strips the threads on the screws? Use a different brand of receptacles? I switched to spec grade receptacles because of the problem.
About 25 years ago I switched to spec grade receptacles because of too many standard grade receptacle failures. I also sent some of the failed receptacles to the certification labs for their inspection and reference.
By the way, if you buy Leviton, the resi grade is the 12650, the commercial is the BR15. They are both made in USA right now. They weren't four years ago, I think they were China for the cheapo and Mexico for the upgrade. We'll see where they are made in another year or two.
I have heard and read with amused interest as to the application of the correct torque - and the measurement of same - to screw terminals. The terms "in-lbs' and "Nm" get tossed around like people knew what they were or if they gave a rat's a**. I have my own scale that has served me well for 30+ years - grunts. The bigger the screw head the more "grunts" of force to apply. My forearm usually tells me when the screw is set.
Good to hear!!! Not to be a Debbie Downer but:
Be sure to keep your calibration records for it. The lawyer will ask for them after a fire. Most need calibrated at least once a year.
Also, you’ll need at least two sets of screwdrivers so you will still have one to use while the other one has been sent off for calibration.
Or, you can keep a new, unused one nearby and throw away the old one after it’s calibration period expires. It may be cheaper than paying for shipping & calibration costs.
Also, make sure you have enough for each of your employees. Or just have one and share.
If you have a decent sized shop, you may want to look into a torque wrench test gauge to have at the shop for guys to test their wrenches against. If it’s in calibration, and guys actually use it, it would go a long way as to a defense.
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