DIY home automation, notification, Part P?

[EFLImpudence]

Good news for a546345 then all of your work would seem to be non-notifiable - even for the kitchen light, as you said, you will only be working on the cable in the loft.

I know we have been through this before but -
1. Work consisting of—
(a)replacing any fixed electrical equipment which does not include the provision of—
(i)any new fixed cabling...
Does that not mean if the work includes new fixed cabling it is notifiable?

No.
It means that the work does not become exempt via provision 1 in Schedule 4.
It does not mean that it cannot become exempt via another provision.

But in a list of the only works which are non-notifiable is a proviso that means these same works would be notifiable.

Replacing any fixed electrical equipment does not appear anywhere else in this list.
So, notifiable if it includes new fixed cabling.

If you reply "only as far as replacements are concerned" then...

...is it non-notifiable to add light fittings and switches which do include new fixed cabling?

Subject to 2(a) and 2(b), yes.

Aside from 2(a) and 2(b) -

NOT notifiable even if it includes new fixed cabling.


Surely that's the part that doesn't make any sense.

 

[ban-all-sheds]

Replacing any fixed electrical equipment does not appear anywhere else in this list.
So, notifiable if it includes new fixed cabling.

If you were replacing something why would you need to add new fixed cables?

NOT notifiable even if it includes new fixed cabling.


Surely that's the part that doesn't make any sense.

Makes perfect sense to me -what is it that you can't get your head around?

 

[bernardgreen]

I thought I'd go for a benign, non controversial thread title!

on this forum ~~~ non controversial ~~~ doesn't exist.

The regulation of hardware used for interfacing ELV SELV and PELV with mains operated equipment can be a burocratic nightmare in the middle of a mine field.

A few months ago a jobsworth wet behind the ears official declared that telephone wiring could not be considered as being ELV as it had 75 volts AC ringing voltages on it.

The same one then accepted equipment with opto isolation with PCB tracks carrying mains less than 4 mm from tracks with the ELV voltages. Under ideal conditions 4 mm will be OK but under humid domestic conditions 4 mm is not adequate. But the relays on the board were safe to switch mains with adequate separation so the PCB assembly must be safe.

One was surprised that he did not insist on the incoming phone cable being bonded to the MET, after all it is connected via approx 200 ohms to ground at the telephone exchange.

Sarcasm aside. Provided all the interface modules are properly designed and the minimum mains to ELV clearances are maintained and components used have the necessary separations and flash testing of isolation then the installation of ELV circuit cabling could be considered as not being notifiable work.

Even so I would always have one leg of the ELV "earthed" to ensure that any breakdown of isolation in any interface that resulted in mains voltages getting onto the ELV would be automatically detected and the mains supply removed before harm could occur to a person using the now unsafe ELV controls

 

[EFLImpudence]

So, notifiable if it includes new fixed cabling.

If you were replacing something why would you need to add new fixed cables?

Probably you would not but 'they' must have considered it a possibility to have included the condition and
then to have considered that this makes the work notifiable.

NOT notifiable even if it includes new fixed cabling.
Surely that's the part that doesn't make any sense.

Makes perfect sense to me -what is it that you can't get your head around?

The illogicality of 'new fixed cabling' being notifiable and non-notifiable dependant on whether the associated accessories are replacements or additions.

I can get my head around the wording but not the reasoning.


Edit - Ah! The replacement could be in a different position and because you also wanted an addition part of the new fixed cabling would be notifiable and part would not.

 

[RF Lighting]

Ah! The replacement could be in a different position

Err then it's not a replacement.

 

[EFLImpudence]

That's another kettle of worms.

 

[SimonH2]

The illogicality of 'new fixed cabling' being notifiable and non-notifiable dependant on whether the associated accessories are replacements or additions.

I can get my head around the wording but not the reasoning.

That puts you in the majority of (probably) 100% ! Schedule 4 really doesn't make sense if you consider logic.

One well expounded upon logic fail is that you can't (for example) add sockets in a kitchen, but you can in a utility room (which may actually be "wetter").

But back to the specific apparent inconsistency you mention ...
Yes, if you consider a light fitting or socket then it seems illogical to say you can replace it without adding new cabling, but you can install a new one with extra cabling. However the replacement bit covers more than just sockets and light fittings (and also IIRC applies in kitchens and bathrooms) - hence although you can't install an extra socket or light in a kitchen, you can replace an existing one.

 

[mattylad]

Is this a big project for the Raspberry Pi?

 

[ban-all-sheds]

Provided all the interface modules are properly designed and the minimum mains to ELV clearances are maintained and components used have the necessary separations and flash testing of isolation then the installation of ELV circuit cabling could be considered as not being notifiable work.

P1 Reasonable provision shall be made in the design and installation of electrical installations in order to protect persons operating, maintaining or altering the installations from fire or injury.

The requirements of this part apply only to electrical installations that are intended to operate at low or extra-low voltage and are—
(a) in or attached to a dwelling;
(b) in the common parts of a building serving one or more dwellings, but excluding power supplies to lifts;
(c) in a building that receives its electricity from a source located within or shared with a dwelling; or
(d) in a garden or in or on land associated with a building where the electricity is from a source located within or shared with a dwelling.

In other words the voltage makes no difference. If, for whatever reason, the cable would be notifiable at LV it is likewise notifiable at ELV.

Even so I would always have one leg of the ELV "earthed" to ensure that any breakdown of isolation in any interface that resulted in mains voltages getting onto the ELV would be automatically detected and the mains supply removed before harm could occur to a person using the now unsafe ELV controls

That was an unsafe modification the last time you proposed it, and it is still unsafe.

 

[ban-all-sheds]

The illogicality of 'new fixed cabling' being notifiable and non-notifiable dependant on whether the associated accessories are replacements or additions.

I can get my head around the wording but not the reasoning.

That's because you are still not operating Schedule 4 properly.

Provision 1 is designed to prevent additions to circuits in kitchens or special locations being passed off as replacements, not to make the installation of new fixed cabling notifiable.

Edit - Ah! The replacement could be in a different position and because you also wanted an addition part of the new fixed cabling would be notifiable and part would not.

No it wouldn't - provision 2 exempts additions.

 

[EFLImpudence]

Right - that does make it clear. Thanks.

 

[bernardgreen]

The requirements of this part apply only to electrical installations that are intended to operate at low or extra-low voltage and are—
(a) in or attached to a dwelling;

I am sure some jobs-worth could interprete that as meaning door bell wiring would need to be notified.

That was an unsafe modification the last time you proposed it, and it is still unsafe.

So you are happy for a door bell push supplied by a transformer in a consumer unit to give an electric shock to callers after a single fault occurs in the CU ?

Consider the ELV control system to a relay controlling mains voltages. Dampness causes creepage between relay contacts and relay coil. ELV circuits are now raised far above ground potential so present a touch hazard that the use of ELV was intended to remove.

 

[ban-all-sheds]

I am sure some jobs-worth could interprete that as meaning door bell wiring would need to be notified.

That would depend on where the wiring was.

What part of this do you not understand?:

So you are happy for a door bell push supplied by a transformer in a consumer unit to give an electric shock to callers after a single fault occurs in the CU ?

No, I'm not.

But I am much happier with that than with the idea of deliberately unseparating a SELV supply.

Are you David Emergencyservicescockburn?

 

[a546345]

Been away for a week. Thanks for the discussion.

Can I ask for opinions on the proposed change to the boiler stat circuit (proposal 3)? The change would be to add a relay in parallel with the existing room thermostat in the hall, and would need some extra 240v cabling. The extra cabling and relay would not be in a special location.

My understanding is that changes to heating controls are specifically mentioned in Part P as notifiable, and that this work therefore would be notifiable.

However, would this work not come under exemption 2.c.1 (shown below) as it is simply adding a "switch" to an existing circuit, and is not in the list of defined "special installations"?

2. Work which—
(a)is not in a kitchen, or a special location;
(b)does not involve work on a special installation; and
(c)consists of—
(i)adding light fittings and switches to an existing circuit,

MattyLad, no not Rasberry PI, but using Homeseer.

 

[Geps]

As someone doing the same type of project - I found it was far easier to just sit down and design the circuits and carry out the inspection and test myself under a LABC building notice.

Most electricians don't 'get' the automation side and those who do charge a premium for it as they tend to work in higher end installs.