Why are proving units so expensive?

[Geordie Spark]

they should at least be 20% cheaper imo. they should be vat exempt

I remember when VAT was first introduced & my old gaffer was having a rant about it: "Value added tax?? .... it adds nothing to the value of anything, it only adds tot he price .... it should be called Price Added Tax !!!"

And there was two different rates wasn't there? One was 8% I think, but not sure what the other rate was, but it was higher. I seem to remember the lower rate being applied to the toys that you put in budgies cages if it didn't have a mirror, but the higher rate applied if it did. (something like that anyway)

 

[MarkieSparkie]

The history of UK VAT here:
Value Added Tax (United Kingdom) - Wikipedia, the free encyclopedia
[url]http://www.ifs.org.uk/fiscalFacts/taxTables
[/URL]

 

[Mark_Burgess]

Yes but how do you know if there's no supply?

A lack of Service head, Meter, Tails, fuse.

 

[Adam W]

A lack of Service head, Meter, Tails, fuse.

Yes, that would be a good indication.

 

[Air Conditioner]

A lack of Service head, Meter, Tails, fuse.

What are they?..........................Only joking!!:smiley2:

 

[Adam W]

I don't think I would have even considered trying to 'safely isolate' an installation which hadn't had a service head fitted yet.
Although if you did, and tried to prove your instrument on the incoming side of the main switch you might think your meter was broken (had you not tried to prove live first).

 

[Steve_P]

Hey!! I used mine today. More to see if it was working than anything. It was so it went back in the bag.

 

[jaresquire]

Simple answer is because the scams require you to have one,thats why they are so dear.Like the nut I once needed for my van,average price of a nut about 50p this one from dealer was about a tenner,when I kicked off about the price the reply was yeah mate course its dear but you cant drive the van without it!

That must be the nut behind the wheel?

 

[Risteard]

I use a Martindale PD690 all the time. Wouldn't be without it. Can be a lot handier than using a known supply at times.

 

[Guest111]

suprised they haven,t started asking where your spare batteries are when you get inspected,when I was at BT they used to have these auditors popping out to check you had everything,and god help you if you didn,t have spare batteries,sods law said they,d always pop up when you had just put your spare set in one of the testers,even though you had the old set to prove the change they still gave you grief for not having a spare set!

 

[DNS1]

Can I assume that the "auto-test" button on the voltage detector isn't a substitute for the proving unit (in the eyes of the NIC?)

 

[DNS1]

Can probably ignore that last post... I've been reliably informed that all the "test" button does is prove the lights work, not that it can detect anything!

 

[thekingiam]

just thinking about this, unless i am wrong the only thing that could be inside a proving unit is a rechargable battery, a capacitor and female connectors surely you could make your own?

 

[spark 68]

just thinking about this, unless i am wrong the only thing that could be inside a proving unit is a rechargable battery, a capacitor and female connectors surely you could make your own?

There is a bit more to it than that, it consists of a small step up circuit to give out a higher voltage than the battery that powers it, some give out circa 240V, and some like my Martindale PD690 give out nominally above 690 V for proving a VI suitable for 3 phase work.

 

[thekingiam]

ok could someone smash one open so we can see how it ticks! please!!!! post pics as well..