The whole idea of torque spanners has been replaced with an amount of turning as the friction on the threads will change the pressure exerted by the screw so it is now a two part operation part one ensures the screw or bolt is tight with a low torque and part two is an amount of turning often in degrees which is calculated to give a set pressure.
Where the environment is carefully monitored the torque wrench or other device can work but this also means a set lubricant for the threads so you know exactly what pressure that torque will exert.
In the motor industry we went through the torque wrench era and have progressed from that. Impact can produce more pressure than torque and to ensure the device is imparting only torque with no impact is hard.
I am sure we have all used electric screwdrivers or drills with a torque setting to drive home screws with ease and I am also sure with any terminals one wants to feel the screw.
One stray strand can bind a terminal so it will kid any torque wrench into thinking it is tight. But experience will alert more electricians and they will correct for a tight screw either giving it a little extra or removing and using a thread repair tool.
The big problem is heat. Any terminal which gets warm will expand and can crush the cable. Checking the torque will result in over a time the cable being crushed to a point where it will shear. Add some vibration as well and this point will arrive even sooner.
What is needed is a terminal which can allow for vibration and reasonable heat without the cable becoming lose as a result. We have all seen the maintenance free terminal where a spring ensures the pressure is maintained.
Once we exceed the point where a screw can exert enough pressure we then move to lugs crimped on the cable over a wider area so more area to remove heat and made of a similar material to the cable. These then may be bolted onto the device and yes one could use a torque wrench but one would check all nuts and bolts were finger free before use.
To me the idea of a torque screw driver is to be able to shift the blame for poor design and product selection away from the electrician fitting the items. But it would be far better to do routine maintenance checking items on a sliding time scale so items where no faults are found have longer re-test time and those where faults are found shorter so reducing the problem with necking off cables. Torque screwdrivers are an attempt to reduce routine maintenance.
Like the one BAS has, my torque wrench goes from 20-110 ft lbs, and I use it most frequently for torquing up the wheel nuts on my car! I did do a web search, and the smallest 1/4 drive torque wrenches I could find start at 5 ft-lbs, so even these do not go low enough for the Redring heaters. I suppose we can look forward to the introduction of extra-low torque wrenches which will be over-priced for what they are, and more instances of connections overheating (and possibly fires) because too much reliance has been placed on MIs and a piece of equipment. What has happened to Common Sense and Experience?????
You can do up the top of a main switch as tight as it'll go, but if you haven't splayed the copper a bit before put it in the switch then a bit of movement on that tail can cause the connection to fail.
Its always amazing how much more you can get on it after you have moved the core around a bit after tightening!
There was a brief bit on it in PE recently, regarding the recommendation to the industry associations that meter installers should be checking con unit incomming terminals after moving teh cores round to replace meter
It does make sense. I've been to so so many with not always loose but often slack incommers.
I was on one job and we heard the incommer arcing away in the main switch. The board was days old and fitted by a colleague of mine when I worked for a company.
The other classic one is breakers 'missing' the busbar. I'm even guilty of that one myself, luckily I spotted it the next day before much load bad been applied.
And Wylex HB breakers (or rather the proteus look-a-like) 3 x 2.5mm in breaker, tendancy to grip only two of the conductors solidily! The current range of dorman smith SP RCBOs have rubbish terminals as well
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