proving unit

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dan.

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righto who uses proving units and mcb locks? thinking im gonna need one for my assesment but will it ever get used again?

 
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If you are being assessed in a house then you shouldn't need locks or a prooving unit.

Proove across the isolator (live side), check for dead on load side and then proove again on the live side.

As you are testing then the isolator switch is enough for isolation without locks, so long as it is reasonably local (not in another building)

 

M107

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righto who uses proving units and mcb locks? thinking im gonna need one for my assesment but will it ever get used again?
Yep I have both & use both.

Although nothing wrong with using the supply side of cu mainswitch when cu is isolated to proove voltage indicator ;) .

Beat me to it Noz

 

M107

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If you are being assessed in a house then you shouldn't need locks or a prooving unit.
Unless you move away from the cu to test at an accessory.

 
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On our assessments, i always comment to the important man 'i would normally close the C/U lid before moving away, but is it ok if i leave it open as your here ?' I also make sure he sees the one lock off and danger electrician at work sign that's in my test kit. Its the only time of the year they see daylight.

 

steptoe

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agree with slips,

I done mine last monday and the guy was top notch.

talked to me throughout and we batted different ideas around,

(this was before he knew i didnt have a 16th!!)

same as before, just commented i would normally lock off and close cover and he said it was fine in this instance as we had total control of the installation(empty house) so no need for any further safety measures.

I proved on incomer side of isolator and he was satisfied with that, I told him only time I ever used a proving box was on industrial and he agreed he could see no reason why to use one on a simple domestic with one C/U.

by the way the house turned out to have a multitude of faults,

(LA void), just vacated the day before,

he was more concerned in my method of testing, order, and what the next result I would expect to be normal, ie, R1 0.31, Rn 0.32, R2 ???

what minimum IR was, and what I would reasonable expect to exceed, etc.

 

gazza96

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I have a proving unit and use it for all my NICEIC assessments, if i use it that's one less thing they can pick me up for, i like to cover all bases when being assessed

 

jay_t

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if you don't have a proving unit and don't have a readily available known supply, clip your voltage indicator to your megger and prove it that way.

 

dan.

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hmmm i like the idea of proving on the main switch but am just worried he might be funny about not having a proving unit. im also wondering if un wiring the live and neutral inside the cu and putting them in connector blocks whist working on the circuit is an acceptable (to the assesor)means of isolation,coz thats the way i do it?i see no reason for mcb locks if its done this way.

 
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hmmm i like the idea of proving on the main switch but am just worried he might be funny about not having a proving unit.
I wouldn't worry to much about proving unit....

I have passed all my assessments without having one...

But make a point of proving the meter is working before & after tests.

When being assessed, I also double check & prove continuity across my leads when doing an Insulation resistance test that has been off scale!

The Key point is..

"YOU MUST SHOW, THAT YOU KNOW, YOU MUST PROVE YOUR METER IS STILL FULLY FUNCTIONAL!"

I'm also wondering if un wiring the live and neutral inside the cu and putting them in connector blocks whist working on the circuit is an acceptable (to the assessor)means of isolation,coz thats the way i do it?i see no reason for mcb locks if its done this way.
Obviously your method is a perfectly safe method of isolating your circuit..

But for what it cost, typically

 

Mr Sworld

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My proving unit came in very handy at the Cornshed gig. Can't really walk back to the genny to check it's still running and re-prove my tester twice! :^O

 
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