Torque Scew drivers

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electricalperson

electricalperson

Senior Member
Location
massachusetts
jmsbrush said:
Guys there are some real good comment being said here, now with that being said the reason I asked.

In one of my educational dvds it states that problems can occur if the connection is to loose or its too tight. The too tight, I'm not really sure why. I can see the being too loose more of a problem.
If a problem were to arise and someone died and you were in court.
If the code expert asked. Did you use a torque screwdriver on all of your connections. If we were too state no ,then we would be liable for not following the code per 110.3 b.
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too tight you can break the connector or put stress fractures in it.

i think using a torque screwdriver for devices is a little over the top but i always use a torque wrench or screwdriver on all circuit breakers and panels and other service equipment. i also use torque screwdrivers when i make up disconnects, cord caps and on machinery. normal plugging and switching on a finish in a house i dont bother just tighten down. on soem instructions from the device companies it doesnt realyl give a torque just says tighten down firmly. but 14 inch pounds is pretty much the standard torque for those things anyway.
 
ivsenroute

ivsenroute

Senior Member
Location
Florida
Just got in from a new service inspection that I had to do with a flashlight outside and in thanks to Old Man Winter and his short days.

Anyway. Only the homeowner was there and I could not give them the OK because:

1) There were 2 neutrals under one terminal screw in the Homeline panel.
2) There were 2 different sized grounding conductors under one terminal screw.

Instead of making a return trip, the owner offered to move them so I handed him my screwdriver and he made the changes.

What is the point of this on this thread?

Because the wire were apparently overtorqued so much that the copper was flattened significantly, creating a very thin portion rather than the full circular mils of the original product.

I can definitely see how overtorquing can be a problem.
 
M

mattsilkwood

Senior Member
Location
missouri
i always use yankee torque wrench, tighten the first one untill it breaks then tighten the rest 1/4 turn less.

ive never used a torque scredriver. i think most guys have a pretty good feel for tight enough.
the only time i break out the torque wrench is on a gear.

i can personally attest to the problems caused by overtightening a meter base. i bet im the only one thats ever done that huh.
 
W

wptski

Senior Member
Location
Warren, MI
ivsenroute said:
Because the wire were apparently overtorqued so much that the copper was flattened significantly, creating a very thin portion rather than the full circular mils of the original product.
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Are you suggesting that a conductor not being round creates a problem? If so, what about the line side of a typical breaker, buss bars, etc.?
 
quogueelectric

quogueelectric

Senior Member
Location
new york
Fulthrotl said:
i don't use screwdrivers at all... i cadweld everything.

however, i do use a fire extinguisher as part of my makeup kit.
carpeting isn't fireproof, i've discovered.
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When I was young dumb and arogant 30 yrs ago I showed my boss how quick I could find the ckt by shorting it out I caught the wallpaper in the marriot hotel on fire in front of him as the breaker didnt trip. Now I am old dumb and arrogant ........... Go figure!!!
 
76nemo

76nemo

Senior Member
Location
Ogdensburg, NY
Torqueing

Torqueing

ivsenroute, I am not sure I follow what you stated. There are many different stabs/terminations in the field. Some are tapered and some are not. With copper being soft annealed it will mash in different ways depending on the termination. Yes, of course a term can be over torqued, but my question to you is what is your point?

You lost me and that is not hard to do. A conductor is sized for a load for a reason as long as it is torqued to manufacturing spec's. If it's slightly mashed as stranded is intended to do, what is your concern???
 
electricalperson

electricalperson

Senior Member
Location
massachusetts
76nemo said:
ivsenroute, I am not sure I follow what you stated. There are many different stabs/terminations in the field. Some are tapered and some are not. With copper being soft annealed it will mash in different ways depending on the termination. Yes, of course a term can be over torqued, but my question to you is what is your point?

You lost me and that is not hard to do. A conductor is sized for a load for a reason as long as it is torqued to manufacturing spec's. If it's slightly mashed as stranded is intended to do, what is your concern???
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if the conductor is slightly crushed it still has the same circular mils. if a conductor is completly crushed then that piece of wire will be so flat that it wont have the same circular mils and wil lcause a problem. ive seen some of the connections those guys that dont use torque wrenches and several strands are crushed and some are even severed. ive actually tightened down terminals so tight on neutral bars ive cut conductors
 
76nemo

76nemo

Senior Member
Location
Ogdensburg, NY
electricalperson said:
if the conductor is slightly crushed it still has the same circular mils. if a conductor is completly crushed then that piece of wire will be so flat that it wont have the same circular mils and wil lcause a problem. ive seen some of the connections those guys that dont use torque wrenches and several strands are crushed and some are even severed. ive actually tightened down terminals so tight on neutral bars ive cut conductors
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As soft as copper is, it will lay flat under a certain amount of stress. I get that Chris. My point was under the right torgue, any conductor will allow load as permitted. I know any conductor can be overtorqued, but my point was that any conductor will pass the same amount of current if properly arranged.
 
W

wptski

Senior Member
Location
Warren, MI
76nemo said:
As soft as copper is, it will lay flat under a certain amount of stress. I get that Chris. My point was under the right torgue, any conductor will allow load as permitted. I know any conductor can be overtorqued, but my point was that any conductor will pass the same amount of current if properly arranged.
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Correct! That's what I was getting at in my post above. Even if deformed a bit, it shouldn't cause any problem at all. In fact, with a flat on solid copper, you'd have more contact area which sounds better to me!
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
mattsilkwood said:
i always use yankee torque wrench, tighten the first one untill it breaks then tighten the rest 1/4 turn less.

ive never used a torque scredriver. i think most guys have a pretty good feel for tight enough.
the only time i break out the torque wrench is on a gear.

i can personally attest to the problems caused by overtightening a meter base. i bet im the only one thats ever done that huh.
Click to expand...
Actually most electricians are amazed at how little force is needed to correctly tighten a connection when you use a torque wrench or screwdriver. That tells me that most connections are too tight.
 
peter d

peter d

Senior Member
Location
New England
don_resqcapt19 said:
Actually most electricians are amazed at how little force is needed to correctly tighten a connection when you use a torque wrench or screwdriver. That tells me that most connections are too tight.
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I agree. The general mentality in this trade is to tighten until it's almost ready to snap or strip out.
 
C

charlietuna

Senior Member
Being in the infrared business since 1989 i have inspected millions of terminations over the years. My opinion is once a termination is properly made per manufacturer's recommendations and not overloaded-it will remain free of problems. Even a properly torqued termination will fail due to overloading it with the extent of overload and time that each overload is applied directly effecting the life of the termination. Where "OVER-TORQUE" problems mainly cause problems is in alignment of contact surfaces which cause electrical problems. Consider a 100 amp fused disconnect switch. The person terminating the line and load conductors should be equally concerned not to over-torque as well as applying rated torque. If the line connections are overtorqued enough to cause mis-alignment of the disconnects contact fingers, the disconnect will not have sufficient surface contact to carry rated amperage without overheating. This problem can only be repaired by replacing the switch. We have followed certain contractors in our area showing a consistant pattern in proper termination skills.
 
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