Kitchens and Part P

[RF Lighting]

NO ONE cares

 

[vsynth]

You can change like for like yourself. But do be 100% sure that you have isolated the circuits.

I can never understand this exemption, changing like for like.

Once a guy brought an extension lead in to work that he had changed the plug on.

He said the washing machine that was powered by this lead failed to work.

I then explained to him that he had the earth wire and live wire connections swapped over...so he had 240V going to the metal body of the washing machine...

He thought brown must mean earth as that's the colour of soil isn't it?

The fact that changing like for like is an exemption seems ludicrous to me.

 

[ColJack]

We can, which means we should agree that it goes

2(a) and
2(b) and
2(c)

'cos if we have

2(a) or
2(b) and
2(c)

then work on special installations becomes non-notifiable...

no it doesn't become non-notifiable at all.. you're brain must be wired different to mine..

your way:
if it's not 2(a) AND not 2(b) then it's not notifiable, meaning it has to satisfy BOTH criteria to qualify

my way:
if it's not 2(a) OR not 2(b) then it's not notifiable, meaning that it only has to satisfy ONE criteria to qualify..

example:
outside power socket

your way:
is it in the kitchen or special location? no
is it a special installation? yes
is the answer to BOTH of the above questions yes? no, so it's not notifiable

my way:
is it in the kitchen or special location? no
is it a special installation? yes
is the answer to EITHER of the above questions yes? yes, so it's notifiable..

 

[ColJack]

NO ONE cares

there's at least 2 of us that care.. so your assertion is flawed..

 

[ban-all-sheds]

your way:
if it's not 2(a) AND not 2(b) then it's not notifiable, meaning it has to satisfy BOTH criteria to qualify

That's right, it does have to satisfy both criteria - it has to be not in a kitchen or special location and it has to be not a special installation.

my way:
if it's not 2(a) OR not 2(b) then it's not notifiable, meaning that it only has to satisfy ONE criteria to qualify..

So with your way, a special installation would not be notifiable if it was not in a kitchen or a special location.

But according to you:

apart from the items listed in part 1,

work in a kitchen is notifiable.
work in a special location is notifiable.
work on a special installation is notiable.
work anywhere else that is not just adding lights or sockets to an existing circuit is notifiable.

.

Which is quite correct, but if you say that it is not notifiable if it's either not in a kitchen or a special location or it's not a special installation, then a special installation becomes not notifiable if it's not in a kitchen.

But special installations are notifiable everywhere.

example:
outside power socket

your way:
is it in the kitchen or special location? no
is it a special installation? yes
is the answer to BOTH of the above questions yes? no, so it's not notifiable

my way:
is it in the kitchen or special location? no
is it a special installation? yes
is the answer to EITHER of the above questions yes? yes, so it's notifiable..

Ah.

You've inverted the tests but not sorted out the boolean operators.

Basically (NOT a OR NOT b) isn't equivalent to (NOT (a OR b)) - draw a truth table and you'll see that the equivalent to (NOT a OR NOT b) is actually (NOT(a AND b)) - you can't play fast and loose with the order of NOTs, ORs & ANDs and come out with the same answer any more than you can do so with +, -, x & ÷ in numeric formulae.

(a) is "is not in a kitchen, or a special location£
(b) is "does not involve work on a special installation".

Remember, the outcomes of 2B are things which are not notifiable, not things which are. We start with the presumption that it's notifiable unless it matches something in 2B. If the work does get a positive match it's not notifiable.

So if we correct those clauses, and use TRUE and FALSE as the result of each test, rather than YES and NO:

Your way

is it not in a kitchen or special location? TRUE
is it not a special installation? FALSE
is the answer to EITHER of the above questions TRUE? Yes, so it's not notifiable.

My way

is it not in a kitchen or special location? TRUE
is it not a special installation? FALSE
is the answer to BOTH of the above questions TRUE? No, so it fails the test for non-notifiable, i.e. it remains notifiable.

 

[ColJack]

That's right, it does have to satisfy both criteria - it has to be not in a kitchen or special location and it has to be not a special installation.

do you not see the flaw in that remark?
you are saying then that ONLY work in a kitchen or special location on a special installation is notifiable? meaning that if it's NOT work on a special installation ( ie adding sockets to existing circuits etc ), then work in a kitchen is NOT notifiable..

 

[Tipper]

Sorry guys.......I thought it was a simple easy question for the clever clogs to answer.

How wrong can I be!

BTW I spent over 30 years in the power industry (apprentice trained mechanical engineer ) so know how to be safe with damned electrickery!

I know, I'll set up a 'Permit for Work' system, padlocks and lock-out boxes to keep myself safe!

 

[ban-all-sheds]

see.. you misread it.. It quite clearly says that it it NOT notifiable if it is NOT work on a special installation.. 2 NOT's cancel each other so it IS notifiable if it IS work on a special installation..

Indeed, but the whole point of 2B is that everything is notifiable unless exempted in 2B. You look in 2B for conditions which are true, and if they are true then the work is not notifiable. You do not look for conditions which are not true where if not true the work is notifiable.

you are confusing the issue here.. we're using language and not boolean algebra to define this..

The problem with language is that "no" can actually have two completely opposite meanings, and fiddling with "nots" can confuse the issue assuming the usual way that people answer questions.

An example:

If had been raining and then stopped, and you said "let's go out for a walk", and someone said "Oh, is it not raining any more?", what one-word answer would you give?

you say that for it to be true that it is NOT notifiable then BOTH condition a AND condition B must be true.. so it has to be both NOT in a kitchen / special location AND it has to NOT be a special installation.

I say that for it to be true that it is NOT notifiable then EITHER condition a OR condition B must be true.. so it has to be NOT in a kitchen / special location OR not be a special installation..

But then your rule breaks down. Whether you use "language" or boolean algebra.

Let's try and establish one crucial point.


Do you think that special installations, e.g. UFH, generators, are notifiable no matter where they are?

 

[ColJack]

heh.. takes a long time to answer in multiquote doesn't it...
it was playing up and not nesting the quotes right so I shortened it..

in answer to your final question
Yes, work on a special installation is notifiable no matter where it is.

please read my edited post above..

 

[ColJack]

lets look at this another way..

"tomorrow I will mow the lawn if it is not cold and not cloudy" <- your structure

this means that you will ONLY mow the lawn if it is both sunny and warm
but not if it's cold but sunny, or warm but cloudy.

"tomorrow I will mow the lawn if it is not cold or not cloudy" <- my structure

this means that you will mow the lawn if is sunny but cold, or if it's warm but overcast, or if it is sunny and warm..

 

[ban-all-sheds]

Yes, work on a special installation is notifiable no matter where it is.

OK.

In that case if you link [is it not in a kitchen or special location] and [is it not a special installation] with or, then as you pointed out, it only needs one of them to be true for it to be not notifiable.

So work which is a special installation, i.e. work which is not [not a special installation] (as you also pointed out, the two nots cancel each other out, so "is not not" &#8801; "is") becomes non-notifiable if the other of the two alternatives is true.

So a special installation which is not in a kitchen or special location becomes non-notifiable.

please read my edited post above..

OK

do you not see the flaw in that remark?
you are saying then that ONLY work in a kitchen or special location on a special installation is notifiable? meaning that if it's NOT work on a special installation ( ie adding sockets to existing circuits etc ), then work in a kitchen is NOT notifiable..

No - you've got 2B around the wrong way again.

2B is not a list of conditions which if false make the work notifiable, it is a list of conditions which if true make it non-notifiable.

And the difference is crucial, because of the way that AND, OR and NOT interact.

As I said above, (NOT (x OR y)) is not the same as ((NOT x) OR (NOT y)).

For the work to be not notifiable via Para 2 of Schedule 2B is has to be

(a) Work which is not in a kitchen or special location

AND it has to be

(b) Work which is not a special installation

AND it has to be

(c) Work which consists of adding light fittings and switches to an existing circuit etc.

It's only by having AND (b) that you don't end up with a special installation being non-notifiable when it's not in a kitchen or special location.

The way that Schedule 2B works is that you stop, and exit with a "non-notifiable" answer as soon as you get a match.

So if you have it saying "It's not notifiable if it's not in a kitchen or special location OR <a list of other conditions>" then you stop if it's not in a kitchen or special location, because the things that come after the OR are irrelevant. You've answered "Yes", or "True" to one of them, i.e. the "not in a kitchen or special location", so you don't need to consider the others, you've come out with a TRUE from your (a) OR (b) OR (c)..

lets look at this another way..

"tomorrow I will mow the lawn if it is not cold and not cloudy" <- your structure

this means that you will ONLY mow the lawn if it is both sunny and warm
but not if it's cold but sunny, or warm but cloudy.

"tomorrow I will mow the lawn if it is not cold or not cloudy" <- my structure

this means that you will mow the lawn if is sunny but cold, or if it's warm but overcast, or if it is sunny and warm..

In this example "mowing the lawn if" is analogous to "becomes non-notifiable if".

I can't stress often enough what 2B is about. 2B is a list of things which if any are true make the work non-notifiable, not a list of things which if any are false make it notifiable.

Sorry if this is a bit large - it might be a struggle to get the right balance between size and legibility.

The shaded square is, I think, what we are both agreed on regarding notifiablity of kitchens, special locations and special installations, and the highlighted parts in the bottom middle square show where your structure breaks down.

It shows hiw, when you reject my structure and adopt yours you end up with a result equivalent to saying that if the work is not a special installation but is in a kitchen or special location, it's non-notifiable, and if it's not in a kitchen or special location but is a special installation, it's non-notifiable.

And that's not the case, and it's not what you know to be the case.

You are quite right about what is and is not notifiable - where you are wrong is thinking that the SI has got it wrong. It has not, and neither has AD P which explicitly puts the implied "and" from the SI into

"Work that is not in a kitchen or special location and does not involve a special installation (e) and consists of:"

 

[ban-all-sheds]

BAS, your logic is flawed

going on your boolean logic it should read

m = x OR y OR z

Well, no it shouldn't, because there aren't 3 conditions there are 2

"not in a kitchen or special location"

&

"not a special installation"

so..
(x) it is in a kitchen = <false>
it is in a special location = <false>
(z) it is a special installation = <true>

You have removed the "not"s, which means that you cannot split 2 conditions (one of which is nested) into 3.

You could do that if the rule was

"It is notifiable if it is in a kitchen or special location or is a special installation".

Then you could indeed say

It is notifiable if it

(x) is in a kitchen

or

is in a special location

or

(z) is a special installation.

But that isn't the logic of para 2 of Schedule 2B - that has "not"s in, and your getting the rules of logical expressions wrong.

(x) is "is not in a kitchen or special location"

That is NOT the same as "is not in a kitchen OR is not in a special location", because the "not" in it applies to both "kitchen" and "special location".

What it is the same as is "is not in a kitchen AND is not in a special location.

Notice that Col 8 is not the same as Col 7, but Col 9 is.

It works just that way in real life too, with the way we mean things.

Let's say you asked your wife to buy you a new tie for an interview, and you said "Any colour but not green or blue"

You mean "not (green or blue)"

You mean "not green and not blue"

You don't mean "not green or not blue", because, as you said, only one would have to be true for the whole thing to work out true. If your wife came back with a blue tie, and said "you said the tie would be OK if it wasn't green or it wasn't blue. This one isn't green, so it's OK", you'd complain that she hadn't done what you asked.

Maybe they should have written 2B(2) with explicit "and"s and no nested "not"s - that would make it clearer, but it would not change the meaning.

What it means is that you do not have to notify work which

is not in a kitchen AND
is not in a special location AND
does not involve work on a special installation AND
consists of—
(i) adding light fittings and switches to an existing circuit; or
(ii) adding socket outlets and fused spurs to an existing ring or radial circuit.

If you start putting ORs where there should be ANDs you end up, as your lawnmowing analogy shows, with work being non-notifiable if it's not a special installation but is in a kitchen or special location, or if it's not in a kitchen or special location but is a special installation.

 

[ColJack]

ok you've convinced me..
as it's written it should be an and..

my brain insists on canceling out all the not's in that list which is why your logic appeared flawed to me..

I read 2B2 as a list of notifiable things and ignore the not's

it IS notifiable if it IS work in a kitchen or special location OR IS work on a special installation... which is true.. hence my earlier list.

if you take an AND and invert the inputs ( so reads as IS and not IS NOT ), and then invert the output, you end up with the output patern of an OR.

IN | NOT|AND|NOT
0 0 | 1 1 | 1 | 0
0 1 | 1 0 | 0 | 1
1 0 | 0 1 | 0 | 1
1 1 | 0 0 | 0 | 1


so IS NOT x IF a IS NOT AND b IS NOT is the same as IS x IF a IS OR b IS...
x = notifiable
a = work in a kitchen or special location
b = a special installation.

 

[ban-all-sheds]

ok you've convinced me..
as it's written it should be an and..

 

[ColJack]

the first "or" confused me too...

where;
a = work in a kitchen
b = work in a special location
c = work on a special installation

IS NOT ( a OR b ) is the same as IS NOT a AND IS NOT b

so my brain automatically went to
IS NOT ( a OR b OR c ) but the regs write it as IS NOT ( a OR b ) AND IS NOT c
so AND IS NOT = OR ???
it's late and my brain hurts now...