partp- consumer unit change

[jason1958]

> needed remedial work because it was noted that the shower
> didn't have a pull-cord in the bathroom and so couldn't be isolated

Actually BS7671 (the law) does not require it.

However the incorrect CPD ratings on the EIC immediately suggests the dead & live tests will equally be fake, which is serious and just not on.

 

[annemarie]

Thanks Jason

On the remedial works bit the electrician didn't mention anything about getting the old kitchen circuit covered by RCD- should he?

The building control electricians did a periodic inspection and testing- will they have done the live and dead testing that is necessary?

Thanks
AM

 

[annemarie]

I guess the issue is ours has been picked up and tested and all is well. But not clear that other customers will be informed.

 

[annemarie]

Actually, Jason- about the shower pull cord. This whole thing first came up because we need a new shower. Doesn't the shower need a pull cord in the bathroom? Is it enough just to have a switch beside the consumer unit- down two flights of stairs?

 

[annemarie]

Last query- it seems that the building control electrician has commented that the 20A fuse for the new kitchen cicruit is too low.
Is that right? Will it be a lot of hassle to change it?

 

[Cremeegg]

Any half way competent electrician (yours obviously isn't) would advise cajoule and persuade you into getting RCD protection all over certainly for any downstairs sockets.

Changing a 20A "fuse" is no problem - if it's an MCB - cost well under a fiver - time about two minutes. However, you must make sure the cable is protected by the fuse; the cable must always be capable of taking more current than the fuse. The cable size depends on the load and other issues such as its route, insulation etc. If it's a standard ring run in 2.5mm2 cable then a 32A fuse is what you would expect. Sometimes you would de-rate a circuit but it sounds like your "electrician" was just making things up.

Glad you are getting somewhere at last. Keep us posted - we like to hear happy endings.

 

[jason1958]

Do not concern yourself re the shower pull cord.
- Provision of such is of direct benefit to you
- Fitters defence that it is not required under BS7671 is immaterial to the *evidence* of falsifying a BS7671 EIC!!

My point was regarding the fitters defence team


Just for the record, there are 2 schools of thought re shower isolators.

1. BS7671 does not require them (unlike Cookers).
In a TN-S/TN-C-S install an MCB is suitable for isolation if locked off (funny little clip & padlock), as is the CU mainswitch.

2. An isolator acts as an (accessible) junction box which i) adds terminals which can become loose (classic is live tightened twice, neutral tightened once) and ii) tempts bathroom fitters to run circuits off them using small size cable (say 1.5mm so it fits) which is not protected by the shower CPD (40A protecting 10mm shower cable).

Even if there is an isolator, you assume live until proven dead. Fluke Voltalert should be in every home, not an expensive item.

Re CU spare ways.
Not happy about the lack of spare ways, should really be 1-2.

It all reads like a rogue trader. Part P is specifically aimed to stamp them out, it was not actually intended to stop competent DIY until hijacked by word changing. That was as much done to stop traders claiming it to be DIY, later amended to add back competent DIY work (eg, time served qualified industrial sparks, elec eng or even C&G lecturers).

So you should get a good resolution with T/S involvement.

 

[annemarie]

The electrician we may get to do the remedial works also told me that a pull cord may not be necessary. But the building control electrical inspection has said that it is NECESSARY and that the new consumer unit can not be signed off until it is done.

Hopefully the electrician we get to do the remedial works will make sense of all this because I am finding it hard

 

[jason1958]

Re upgrading the 20A CPD.

A radial wired in 2.5mm must be protected by 20A CPD (or less).
A radial wired in 4.0mm can be protected by 20A or 32A CPD.

A ring wired in 2.5mm can be protected by 20A or 32A CPD.
It comes down to cable installation re Grouping, Ambient, Insulation & type of fuse (old BS3036 rewireable, irrelevant here).


Is a 20A radial sufficient for a kitchen?
If the kitchen SIZE means it can handle cooker, worktop, kettle/toaster, then ok. However I would suggest a cooker with socket-in-the-control unit (because it is on a separate circuit). Such as where you have a separate utility room with washer, dryer, fridge1, fridge-freezer2.
If the kitchen SIZE means it can handle washer, dryer, freezers, dishwasher all in the same place then 2-3 20A radials or 1 32A rings.

If using a ring the ring should be balanced (load not all at one end re cable length/routing), otherwise two 20A radials might be better. Diversity applies to appliances - washers & kettles/toasters do not run at 100% continually, however dryers do so they can benefit from a 20A radial of their own or shared with say the fridge/freezers.

If they did not want to RCD the kitchen power f.c. they should have stuck an RCD socket outside or near the backdoor (they don't cost much).

 

[jason1958]

Remedial Electrician (could be a job description there, stick their number below kitchen fitters business card addresses will probably
a) fit one or
b) ask BCO to quote the reg requiring one in BS7671

BTW, there are cable tracers available to track cable routes.
Fluke do one at about £400, think it is called Cabledetect 2424T, mine is covered in plaster so I can't remember the name & part number off the top of my head. Bought because 1950s wiring is anywhere but in zones, as in diagonal, and yes, upstairs lights fed off a diagonal run behind a cast-iron bath. That would have been fun to drill into. The installer was the senior inspector of the local electricity board, a distant relative. Thought about digging his bones up, asking him to pull himself together and fix what he did. It was compliant with regs and all oversized, almost unique FTE for 1948-1952 (black PVC sheath, polythene insulation, earth sleeved green along its length like modern french cabling).

Bosch DMF10 Zoom is a simple one, but can be confused by any metal mesh in the wall (typically used to span mixed wood doorframe/stud, cinderblock, brick). If you find it detects live when not, put your other hand on the wall when using it - should say in the instructions, but it stops false positives which can be common with some people/houses.

 

[annemarie]

To be fair the new kitchen ring is only for fridge/freezer, dishwasher and toaster/kettle, food mixer.
The washer (and future dryer) are in a seperate room.
I think the 20A is probably OK.

I will give a progress update.

 

[Spark123]

> needed remedial work because it was noted that the shower
> didn't have a pull-cord in the bathroom and so couldn't be isolated

Actually BS7671 (the law) does not require it.

However the incorrect CPD ratings on the EIC immediately suggests the dead & live tests will equally be fake, which is serious and just not on.

BS7671 is not the law - it is non statutory. It may however be used in a court of law to claim complicance with a statutory document. As this is a 16th edition installation there is nothing in them re the shower isolator switch. On the other hand, if the manufacturer of the shower requires an isolator switch then one must be installed.

 

[jason1958]

1. Yes, BR AD "P" Schedule 1 is the law.

Compliance with Schedule 1 may be demonstrated via...
i) adherence to BS7671, or
ii) adherence any defined standard, or
iii) any design which someone is willing to sign off as meeting Schedule 1

In the absence of a defined standard then BS7671 is used as a benchmark - by any PIR or court.

2. Most wiring accessory instructions require installation to...
i) BS7671
ii) nth wiring regulations
iii) current wiring regulations

That does not mean you can not deviate, but it does make things more complicated from a legal perspective. You can still use a named standard or deviation, but the wiring accessory manufacturer may not support usage under such.

If the shower manufacturer requires an isolator, then it does.
If the shower manufacturer requires "must be installed to BS7671", then it does not.

 

[ban-all-sheds]

1. Yes, BR AD "P" Schedule 1 is the law.

No it's not.

The Building Act is law.

The Building Regulations are law.

Approved Documents are not.

 

[ebee]

When did shower manufactures start making the law?
I thought it was parliment and they might allow an appointed gov minister to vary it slightly.