Testing...how far do you go?

[Dave 85]

Be honest here guys...When you do your testing, do you do it exactly the same as you would during a college assessment on every installation you work on/install
I dont, and I've never known a sparky who does
Feel free to accuse me of being a cowboy but here are the things I do different...

If im IR testing an old install and I get, say 50Mohms across the main Neutral/Phase and earth bars I'll write down every circuit as >200 rather than rip the fuseboard apart trying to find the circuit/circuits with less than 200. It doesn't really acheive anything IMO and takes time..
I never IR 500volts between L and N on an existing installation if the reading to earth is good, the risk of damaging the clients property is too great IMO

If im testing a new ring circuit installed by myself I'll test end to end on all 3 conductors but won't carry out cross connected ring continuity tests. On my own circuit I know its wired as a ring so this test is completely pointless.

On my own installations, if I know the chances of parallel paths etc are zero I sometimes gain my R1+R2 reading for a radial by testing Zs at the furthest point and deducting Ze. IMO this proves beyond all doubt you have a good R2. Now I know you're supposed to prove the circuits are compliant before energizing but we're all trying to make a living here and whats the worst that can happen when you know you do good connections every time and its all RCD'd

Also when I do a consumer unit change I do not test and inspect the installation to the same extent as I would an EICR. I just test ring end to end, IR L/N-E, RCD time, Ze and Zs at the end of each circuit-The going rate for C/U's (£350) does not really allow for a whole day of testing and inspection and the house is gonna be 10 times safer than before I turned up anyway.

Hopefully this should arouse some fiery debate
Seems a bit of a case of common sense vs blindly following the rules you've been given without questioning the neccessity....

 

[joe_berks]

this is reality. and the install is safe. the zs is low enough to trip the breaker in the required time. to me it is more about the visual inspection , dropping 90% of sockets switches and isolators etc and making tons of observations. if nothing is tripping out the breakers well thats your IR fine isnt it? to me that is more about testing an install before energising i would always IR test everything. but if it is on and being used already, come on man use your loaf son.

 

[Tonkatoy27]

My ELECSA assessor is pretty practical and experienced. (I should hope so) He advised me that when changing a CU to ins res all circuits at the same time, L and N bar strapped together tested to earth. If it's over 2M ohms then you know that individually they are much higher and will pass. With said example of 50Mohm then you write 50Mohm in all phase-cpc boxes, it's not false, it's what you measured albeit with all the circuits connected together. When I used handwritten test forms I'd write
L-N/CPC at the top to make it plain the L and N were strapped together when I'd done it. (more difficult with the PDF's I use now)
Agreed, L-N test is of negligible use. My assessor didn't seem to think it was important either. The risk of trashing electronic equipment far outweighs the value of the test.

I can't believe some sparkies see working live on the odd occation as such a problem, I agree they've probably had it thumped into them not to do it by the H&S ----'s. Fault finding for example is sometimes much easier live.

Well done Dave 85 for being honest and starting the discussion. We all might pick up some pointers. If you're just gonna slag people off then don't comment, it's not helpfull.

 

[joe_berks]

my friend found one in a loft, had wood panelling like in a bentley, and a luxurious leather shoulder bag

 

[Top Cat]

my friend found one in a loft, had wood panelling like in a bentley, and a luxurious leather shoulder bag

Beautiful!

 

[mark ju]

Remember the wind up meggers when you could actually "feel" a fault in the resistance of turning the handle. Wish i still had mine!

Also very useful for teaching apprentices to not be SO TRUSTING !

 

[Deleted member 9648]

If you test an entire install and get an IR of 50 megs,then put on the form exactly that. I regularly do this, and write on the first circuit detail 'IR overall reading of all circuits'.....on the second circuit IR box I write the results.....been doing this for years and our NIC bloke has always been happy.....why do you have to fill in each circuit?

 

[Dave 85]

If you test an entire install and get an IR of 50 megs,then put on the form exactly that. I regularly do this, and write on the first circuit detail 'IR overall reading of all circuits'.....on the second circuit IR box I write the results.....been doing this for years and our NIC bloke has always been happy.....why do you have to fill in each circuit?

This seems to be the way to go, Ill do it in future. Guess I was worried that I'd get pulled up for not filling certs properly by my assessor.
Out of interest do you guys RCD test every circuit on a dual RCD board? I used to but now just test one circuit on each side.

 

[Anthony King]

anthony king i am going to hazard a guess that youve not done a great deal of real life testing. this man is probably a lot more experienced than you . so have some respect . what dave says is 50ohms across the whole install . you may even find that on a large enough install, every circuit is >200 individually tested, but if you test at the tails it will be reduced as it dissipates across the large area. numpty. you dont know the ways of the spark, so LLLEEEEAAAVVVEEE IT YEAH?

You never commented on dave not testing R1 + R2, your allready at the furthest point when doing zs, so it would take 2 mins more to carry this test out, and the safe isolation procedure seems to have gone out the window, actually i do a great deal of testing for a large chain of pubs, and i know that results can be hard to obtain especially when nothing is marked up at db or at any point on the circuit. Every one has to work live at some point i dont dissagree with that.
Oh and i never disagreed with the IR test or the results either.

 

[mark ju]

Be honest here guys...When you do your testing, do you do it exactly the same as you would during a college assessment on every installation you work on/install
I dont, and I've never known a sparky who does
Feel free to accuse me of being a cowboy but here are the things I do different...

If im IR testing an old install and I get, say 50Mohms across the main Neutral/Phase and earth bars I'll write down every circuit as >200 rather than rip the fuseboard apart trying to find the circuit/circuits with less than 200. It doesn't really acheive anything IMO and takes time..
I never IR 500volts between L and N on an existing installation if the reading to earth is good, the risk of damaging the clients property is too great IMO

If im testing a new ring circuit installed by myself I'll test end to end on all 3 conductors but won't carry out cross connected ring continuity tests. On my own circuit I know its wired as a ring so this test is completely pointless.

On my own installations, if I know the chances of parallel paths etc are zero I sometimes gain my R1+R2 reading for a radial by testing Zs at the furthest point and deducting Ze. IMO this proves beyond all doubt you have a good R2. Now I know you're supposed to prove the circuits are compliant before energizing but we're all trying to make a living here and whats the worst that can happen when you know you do good connections every time and its all RCD'd

Also when I do a consumer unit change I do not test and inspect the installation to the same extent as I would an EICR. I just test ring end to end, IR L/N-E, RCD time, Ze and Zs at the end of each circuit-The going rate for C/U's (£350) does not really allow for a whole day of testing and inspection and the house is gonna be 10 times safer than before I turned up anyway.

Hopefully this should arouse some fiery debate
Seems a bit of a case of common sense vs blindly following the rules you've been given without questioning the neccessity....

You talk common sense here. Far better this than the method i once saw when working for quite a well known local contractor and that was to fill out certs, without even leaving the office!
Kind of backfired when a customer had his sparks test his property, prior to doing some work, and found a break in a ring, despite the cert showing continuity readings, Turned out a plumber had hung a radiator over a hall socket, site sparks too lazy/stupid/irresponsible to even make the most basic of checks on second fixing and the office signed it off and made up all the readings! Seen this sort of thing done by several contractors now, all on new build domestic work. Bas***s quite often get away with it!

 

[Dave 85]

You never commented on dave not testing R1 + R2, your allready at the furthest point when doing zs, so it would take 2 mins more to carry this test out, and the safe isolation procedure seems to have gone out the window, actually i do a great deal of testing for a large chain of pubs, and i know that results can be hard to obtain especially when nothing is marked up at db or at any point on the circuit. Every one has to work live at some point i dont dissagree with that.
Oh and i never disagreed with the IR test or the results either.

You've changed your tune pal....
You not gonna accuse Mark ju, Joe berks, tonkatoy27and Biff 55 of all being cowboys for more or less confirming everything I said?
No.....
Thought not.

 

[Tonkatoy27]

You are testing the RCD, so one test on each RCD at a 17th board, tested at the CU if you want, is fine.

 

[Tonkatoy27]

I find some people jump to the cowboy references far too quickly on here sometimes, just because someone does something different to the way they do it. My now fully qualified apprentice sometimes takles jobs completely differently from the way I would, it doesn't make him wrong, it just means his thought process is different. Spouting off to someone and calling them names without knowing them isn't very mature and doesn't contribute at all. (schoolyard bully springs to mind)
I see this forum as somewhere qualified sparkies can discuss and learn from each other. However, the DIYer trying to get us to tell him how to wire up his new bathroom lights so he can save a few quid should only be told one piece of advice. Get an electrician in.

 

[Dave 85]

I find some people jump to the cowboy references far too quickly on here sometimes, just because someone does something different to the way they do it. My now fully qualified apprentice sometimes takles jobs completely differently from the way I would, it doesn't make him wrong, it just means his thought process is different. Spouting off to someone and calling them names without knowing them isn't very mature and doesn't contribute at all. (schoolyard bully springs to mind)
I see this forum as somewhere qualified sparkies can discuss and learn from each other. However, the DIYer trying to get us to tell him how to wire up his new bathroom lights so he can save a few quid should only be told one piece of advice. Get an electrician in.

Oh Ive been called cowboy, DIY'er, Electrical Trainee, menace to society etc etc more times than I can remember on these forums. I must admit I do enjoy sitting back and watching people make idiots of themselves. Its quite easy to see how much weight someones opinion carries on these forums by viewing their profile and the people throwing these kind of accusations around usually carry very little.

 

[Chris_Harvey]

As said above RCD test is for each RCD so one test on each is the right way surely, well this is the way i was taught. I also work live on occasions as its not possible to work dead all the time and i would consider myself a new spark having been trained and qualified in the latter end of the 16th edition. Am i scared of it NO, do i respect it YES. I have had a good belt on more than one occasion and that alone makes you respect what your doing more.

The cowboy word is thrown around too often in my opinion before all the facts are gained. Just because someone has a different way of doing things doesn't make them a cowboy and just because they did a Electrical Trainee course also doesn't make them a cowboy but, not testing at all or drive by testing = cowboy, those who just throw it in switch it on and collect the money without a care in the world.
Dave 85 you may not have be recording the info right before but, you were testing it (maybe not to the liking of everyone) and would have investigated further if it had been wrong. Whats wrong with that! Certainly no cowboy in my eyes.

rant over
chris

 

[Guest55]

Out of interest do you guys RCD test every circuit on a dual RCD board? I used to but now just test one circuit on each side.

Do rcd tests at the board with all mcbs turned off to reduce " electronic noise " from appliances.
2 rcd CU = 2 separate tests at the device.