Biddy17

reading the guide it really doesn't make sense to me

especially when it says this:
Before touching equipment conductors, test for LIVE! Test between—all conductors and known earth. (This test also includes testing for LIVE between the protective earthing conductor and the known earth). Test between—all conductors at the equipment end.

this follows testing for live at the appliance, posting danger tags and finding the CB.. so what is it wanting me to do then? test both sides of the cb? test the cb then go back to the appliance (what ive already tested)

even more baffling, there is no step to test the appliance AFTER its been isolated and locked off.. am I mis reading this or what?

Jockstar

Now its been years since i did my trade best. But maybe its telling you to test your test equipment on a known source?

Biddy17

I just don't know what it means by "before touching equipment conductors test for LIVE" This is after already testing for live at the appliance.. So does it want me to test for lie at the board? Then it says test at the equipment end.. What is the equipment end?? is it the appliance again? Doing my head in.. Why would I test the appliance twice before turning off the CB?

old.sparkles

I think the retest is to prove that you have isolated the correct circuit and there are no other supplies feeding it - actually proving the part that you are working on is dead at the point you are working

Is this the procedure you are reading - http://www.vetassess.com.au/download...101020130819PM

Biddy17

Yes that's the one old sparkles,

That would make sense what you say but, it's before it says isolate circuit. So how I'm reading it it says test appliance is live, affix danger tags, locate CB that is feeding the appliance, then it seems to be saying test at equipment end again.. Before actually flicking any CB! Am I interpreting it wrong..

How would you interpret the disconnection process?

old.sparkles

I could see a test before you isolate - and one after you have isolated - which is what I would probably do anyway - and when you've proved it dead lock it off.

Biddy17

Ok so by the step determine the location of the protective device, does that actually mean turning it off then?

And then it says before touching equipment conductors test for live, does this mean check out going side of CB?

And then it says check at equipment end which is obv the appliance. Don't want to sound daft here. I know exactly how I'd do a safe isolation safely. But I nee to do it how they want me to.. An I just think it could have been worded better to avoid confusion

old.sparkles

I've just re-read their procedure, and it doesn't make a great deal of sense to me either (sorry - only skim read it earlier).

Looks like you confirm the frame isn't live. Test for voltage on equipment, or start motor and isolate at local isolator. Then find the breaker and confirm that's live and isolate. It's not very clear, and not how I would do it either - there seems to be no check after isolation either locally or at the protective device that it is dead. Do at least what they ask for - and add any steps necessary to prove it's safe maybe.

Biddy17

Haha thanks for that! It's not just me going crazy then! Yeah I think that is the best way, defo going to test that it's dead after I isolate! Should be a fail if not! Thanks for your help

whaleshark

I've just been reading that part of the form tonight, and I was thinking the same thing. What a load of rubbish.

Seems to me that it could be to be a money making scheme, to make a simple procedure we do every day sound ridiculously complicated and tricky so you fail. And because they know you're desperate to pass, they know you WILL pay another grand to do it all again. Or maybe I'm just being cynical! Ha.

I've got my assessment coming up, I hope it isn't the farce it sounds like.

Still none the wiser about the safe isolation though mate. What do you make of it?

Biddy17

Tho only possibly thing I can think of is if you look at it this way and it sort of starts making sense then... If studied it hard and this is my only reasonable explanation.

So everything is fine and dandy until we hit the locate protective device part. I think this stage actually means locate and turn off. Then test for live and then isolate by locking off breaker etc

nexsuperne

By the sounds of it, this is just a sandwich test.
1)Test for live before isolator to prove your test gear works.
2) Isolate the circuit in question and test to make sure it is dead
3)test the incoming side of the isolator to prove that your test equipment is still working. Otherwise, the voltage indicator battery could have failed between step one and two, and you then think its dead when it isnt!

Check all combinations of Live/Earth/Neutral for potential, as if the Main earth point has failed, then your 2 lead tester will show zero volts, even if Live is present.

Do they supply a lock-off kit on these tests, or should I bring my own?

Also this procedure is how we work on motors in the slaughter house, to stop people switching the supply back on when swapping DOL starters out

old.sparkles

Did you actually read the procedure - it doesn't say test after isolating, it says make conductors safe. I'd add in the test after isolating too

nexsuperne

I have a 'Trade test' of sorts every year, when my NICEIC assessor comes to check 3 examples of my work. I have had the same assessor since 2005, so I know what the routine is. We go through my Health & Safety policy, Liability insurance, every test certificate issued since the last time he saw me, test equipment in use and then we have to go out to 3 jobs that he chooses to see examples of my work. There is no knowing which 3 it will be, and there is no time to fix them, so every job I do must be up to code. When on site, I am asked to make the installation safe, demonstrate safe isolation, use a lock-off kit, test for IR, test for continuity, carry out a Ze, run a R1R2 measurement, calculate Zs from R1R2+Ze, trip the RCDs and see if the trip time and current is compliant...and all of this must be close to the readings recorded on the original installation date to prove that the meter is holding its calibration!
I did get one useful pointer though, and that was the issue of paying to have my meter calibrated is a waste of time. It could be dropped by the courier after calibration and I'd never know. So my assessor said that I should have a series of resistors (1Ω, 1MΩ, etc) and a known RCD protected socket to act as a reference point to test against once a month. This way, if my meter was dropped, or the results were significantly different from the previous month, then I would know and could then arrange repair and retest the work for that month, not the whole year.

nexsuperne

The only way to prove the conductors are safe is to test after isolating, but once the circuit for the appliance has been identified, then the safe isolation procedure at the point of origin surely would be sufficient.