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Topic Title: Guidance on terminal torque
Topic Summary: Is there any?
Created On: 14 February 2013 06:03 PM
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 20 February 2013 05:01 PM
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rocknroll

Posts: 8842
Joined: 03 October 2005

Originally posted by: OMS

I can see a business opportunity here, a bacon bap calibration day , I can supply the test equipment and necessary computer equipment, OMS can be the technical adjuster and we might be able to hire Zs with her rocknroll pinny to man the barby.


LoL - now you aren't taking this very serious issue very seriously - I'm more than happy to loll about making "technical adjustments" and trying not to laugh, I'm guessing you are too - but come on, Zs in a pinny - that's stretching things a bit far even for you - we couldn't charge enough to cover that, old son -

OMS


LOL you might be right from what I hear along the grapevine!!!

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------
 20 February 2013 05:28 PM
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OMS

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LOL you might be right from what I hear along the grapevine!!!


Shhh - orders, can't say -

OMS

-------------------------
Failure is always an option
 20 February 2013 06:11 PM
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NeilBush

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£15 is admittedly the lowest I've heard for a non-UKAS calibrator. £25 is the highest I've heard from a UKAS calibrator.

£22 seems to be an industry norm for calibrating a variable unit with a UKAS compliant company.

When I say industry norm, you should maybe keep it in mind that UK Engineers use tens of thousands of torque screwdrivers already. I have customers who buy 200-300 units at a time.

Although the introduction of 1000V insulated choices has meant that Electrician's are now joining the party - the infrastructure is already well in place.

-------------------------
I have an interest in Wiha Tools
www.wiha.com/england
 21 February 2013 04:21 PM
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DR2366

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Questions put to hager technical in relation to the chart info supplied:

Can you tell me what tolerance there is on these figures as different standards of torque devices have different levels of accuracy ie +-6% or +-10%?

The written installations instructions refer to 2 Nm as a minimum requirement, are the figures in the chart minimum figures as well?

Answers given:

These are the recommended torque settings as recommended by Hager.

Obviously common sense must prevail and the figures stated must be used as minimum but + 10% should not present a problem.


So pick the bones out of that then!

Is a manufactures recommendation the same as a manufactures instruction?

We have minimum torque figures but also common sense must prevail.

So do we a buy torque screwdrivers to ensure the minimum recommended torque figure is achieved and if we do it up tighter its because we used our common sense?

I'm still confused as to if we need one?
 21 February 2013 04:28 PM
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DR2366

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recommended past participle, past tense of rec·om·mend (Verb)
Verb
1.Put forward (someone or something) with approval as being suitable for a particular purpose or role.
2.Advise or suggest (something) as a course of action.

instructions plural of in·struc·tion (Noun)
Noun
1.A direction or order: "he issued instructions to the sheriff".
2.Directions to a lawyer or to a jury.
 21 February 2013 05:57 PM
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NeilBush

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Drivers which are +-6% are the ones which achieve the EN 6789 torque tool standards. They have a permanent etched serial number so that they can be traced back through their life, all your calibration certificates over the years and all the way to our factory and the person who calibrated it on day dot and gave it the first certificate. These +-6% models make up 95% of the unit sales of torque drivers.

Drivers which are +-10% are more economical to manufacture and they don't come with any kind of serial number or traceability. They're usually not variable. They're not 1000V VDE. They are good to a point but when only 1 in 20 people buy at this level you might wish to weigh up the pros and cons, quarter of the price, tool life, zero traceability, is there such a thing as a free lunch etc.

-------------------------
I have an interest in Wiha Tools
www.wiha.com/england
 21 February 2013 07:21 PM
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DR2366

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With respect having worked within an accredited test laboratory with many items of equipment both electrical and mechanical which were traceable to national standards, the fact an item has an etched serial number isn't that important.

A unique number to identify the item will do which is of a permanent nature. As to the tolerance required, doesn't this need to be proportional to the accuracy required?

Once a piece of test equipment is calibrated it becomes traceable even if it is cheap.

If you don't intend to use the item on live terminals then you don't need it to be VDE. Checking live terminals as part of an EICR on which you're not allowed to isolate might be an example where it would be useful.

I appreciate your input Neil but perhaps it would be helpful if you could expand on the nature of your interest in wiha Tools?

Edited: 21 February 2013 at 07:28 PM by DR2366
 22 February 2013 03:07 PM
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NeilBush

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I'm the UK's National Account Manager - if you've met a Wiha-employed salesman since the summer of 2010 then it was me.

There are of course many people in the chain who can talk about Wiha with you at shows.

-------------------------
I have an interest in Wiha Tools
www.wiha.com/england
 22 February 2013 04:57 PM
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Jaymack

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I bought a couple of CK Modulo screwdrivers some time ago, specifically to use on distribution boards screws, after seeing the publicity around them and how efficient they are. I thoroughly recommend them.

I have no intention of buying torque screwdrivers unless required to do so, since my technique in tightening screws has been developed over many years, assisted no doubt by Barclays in my formative years.

Regards

http://www.screwfix.com/p/ck-d...set-2-piecec-set/75139
 23 February 2013 07:57 AM
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tomgunn

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Well - reading between the lines here - I think that its fair to say that everyone now has to own a torque screwdriver otherwise you cannot do any electrical work anymore - and it also seems, ( cant believe this is all true!! ), that this torque screwdriver has to be 'calibrated' every year? I also understand that these torque screwdrivers have a deficiency of, lets keep this simple, around the 5% mark? Hahahahaha!

Please - someone tell me that this is just a wind up - an early April fools day prank!

Tom

-------------------------
Tom .... ( The TERMINATOR ).

handyTRADESMAN ... haha

Castle Builders

Why did Nick Clegg cross the road? Because he said he wouldn't!

I can resist anything..... except temptation! ( Karl Gunn ).

Edited: 23 February 2013 at 09:35 AM by tomgunn
 23 February 2013 12:06 PM
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rogersmith7671

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Special tools will always be needed as installation tech moves onward at a relentless pace. Over time all sorts of expensive tools become out-dated as "improvements" in cable and equipment become standard items (eg; pyro strippers).
The most outstanding example of development in electrician tools has been the introduction of the "smart phone", enabling anyone with moderate experience to expert, with almost instant assess to knowledge and a wealth of experience undreamed of just a few years ago.
Got a problem with the Regs? how do you fit that funny looking box? Can I get away without bonding this or that bathroom? all these questions and many more can be answered onsite with a "quick Google on me Iphone" (don't worry they can't touch you for it).

Regards
 23 February 2013 01:07 PM
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DR2366

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I think there's a lack of continuity across the industry still on the subject. To be honest I expected to be directed towards guidance from the bodies or some evidence to support the importance being placed on the topic by some. I suspect that more people don't own one than do (based on feeling not evidence), perhaps Neil could give us an idea on sales figures and when the product became available to help gauge this.

I expected to learn something more from the manufactures but it would seem that I have more questions now than I did when I started with their information and attitude. Why hasn't this been more of an issue on other electrical accessories and pieces of equipment, showers would a good example?

Mira 10.8kW sport max instructions say: "Tighten the screws in the terminal block, ensure the wires are secure and tight. "

You can tighten the terminal to the correct torque if you own a torque screwdriver. It could still come loose in a short time afterwards for a number of reasons and then what happens?

Edited: 23 February 2013 at 01:14 PM by DR2366
 24 February 2013 10:10 AM
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NeilBush

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5,500 UK sparks have bought a VDE torque screwdriver so far and the graph is getting steeper. The product is now past the "early adopter" phase of a product life cycle and is becoming more main stream and normal. 80% of sparks currently wouldn't have a clue that torque values exist and that the ball is at their feet. You are the minority.

-------------------------
I have an interest in Wiha Tools
www.wiha.com/england
 24 February 2013 10:52 AM
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MrP

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Neil
You are trying to defend the indefensible
For a Joe sparkie to buy a torque screw driver he would have to be either crackers or got far too much money or both
As I believe public hanging was very popular at one stage

MrP Home in four days
 24 February 2013 02:25 PM
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DR2366

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I fitted a MK Sentry garage board and the instructions say "ensure all screw terminals are tightened to the correct torque figure as shown below.

Terminal Bar 1-1.5Nm
RCD & MCBs 2-2.5Nm

The 10 year guarantee is conditional that the product has been installed operated or maintained in accordance with the instructions.

I don't have a torque screwdriver (yet Neil, wink wink) and could anyone prove that I didn't tighten the terminals to thoses figures, could I prove I did?

Neil as you have an interest perhaps you could contact MK and ask what the maintenance requirements are on terminals are. MK Technical number is 01268 563720. PS did you get my private message!
 24 February 2013 04:54 PM
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rocknroll

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Originally posted by: NeilBush

5,500 UK sparks have bought a VDE torque screwdriver so far and the graph is getting steeper. The product is now past the "early adopter" phase of a product life cycle and is becoming more main stream and normal. 80% of sparks currently wouldn't have a clue that torque values exist and that the ball is at their feet. You are the minority.


Well that leaves around 100,500 out there still competently using their favourite screwdriver to keep our nation turning.

I suspect these 80% are the people with common sense and the less gullible to sales pitches and they know there is not a problem in this area, when I put it through my electrician that I use he used a similar argument to most on here, "if I have not learned after 28 years without the aid of an expensive torque screwdriver how to tighten up a terminal adequately and without compromising the conductor, then I think it is time to give up and hand over to those easily led weak minded schoolboy FDW's with their books and fancy gadgets that are in abundance at the moment."

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------
 24 February 2013 05:05 PM
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rocknroll

Posts: 8842
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Originally posted by: DR2366

I fitted a MK Sentry garage board and the instructions say "ensure all screw terminals are tightened to the correct torque figure as shown below.

Terminal Bar 1-1.5Nm

RCD & MCBs 2-2.5Nm

The 10 year guarantee is conditional that the product has been installed operated or maintained in accordance with the instructions.

I don't have a torque screwdriver (yet Neil, wink wink) and could anyone prove that I didn't tighten the terminals to thoses figures, could I prove I did?

Neil as you have an interest perhaps you could contact MK and ask what the maintenance requirements are on terminals are. MK Technical number is 01268 563720. PS did you get my private message!


I think now after pushing this one to the top all the time and attempting to use strange convincing arguments in favour of Mr WIHA's tool that you are part of his pyramid selling scheme and a blatant attempt to breach the rules regarding advertising on this forum.

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------
 24 February 2013 07:11 PM
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DR2366

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That's not the case at all rocknroll, but you can't blame a bloke for trying to get a free gadget. I don't own one and don't want to buy one and calibrate it annually either but that may turn out not to be my choice if I can't counter a view point of "its in the instructions so you must do it".

If I've contravened the rules of the forum then I apologise to all.

I've tried to post facts whether from product instructions or from email communications with technical departments in an attempt to make an informed decision on the subject.

In some cases these support the use of a torque screwdriver and some do not. I certainly feel more informed on the issue now then when I started and isn't that the purpose of the forum. If you feel the topic isn't in the in the common interest or I am trying to promote the wiha product then please report me to the moderators and I will abide by their decision. I would be just as happy to have a discussion with any other product suppliers in this field in order to increase my knowledge on the subject.

The forum conditions of use state:
The discussion areas are provided by the Institution of Engineering and Technology, in order to assist its members and others in exchanging views on current issues and matters of common interest.

The discussion areas may not be used for the promotion of products and services of any kind, nor for recruitment advertising; potential advertisers are invited to contact our Advertising Department. However, this condition should not discourage users from suggesting a product that may assist a genuine enquirer who has raised a specific problem. In such circumstances, users should obey the custom among professional engineers of declaring any interest.

Ps sorry for posting a reply and putting the topic too the top again, that's just the way the forum system works!
 25 February 2013 09:11 AM
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MrP

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While the post is at the top
The words flogging and dead horse come to mind
MrP
 25 February 2013 09:57 AM
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AJJewsbury

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I fitted a MK Sentry garage board and the instructions say "ensure all screw terminals are tightened to the correct torque figure as shown below.

Terminal Bar 1-1.5Nm
RCD & MCBs 2-2.5Nm

AD M (based on statutory building regs) says I need to mount the CU with a certain range of heights - so do I need to buy a precision tape measure and get it annually calibrated?

It would be interesting experiment to find out what sort of torque values electrician's achieve "freehand" using an ordinary screwdriver. If it could be shown that acceptable values could be achieved consistently just by 'feel', might we have an argument that the individual could be regarded as 'calibrated' so avoiding the need for calibrated tools.

- Andy.
IET » Wiring and the regulations » Guidance on terminal torque

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