CU change for assessment.

[vandalay]

Alright gents, bit of advice needed in getting ready to change CU in my own house for a provider assessment probably with ELECSA.

Tested house and all results are fine, will i have to put this on a PIR form or will they just want to see a EIC.

As I will upgrading to a 17th board will I have fit mains smoke alarms to replace the fire brigade fitted ones, if I do(probably will) am I right in thinking I dont have to go to the board but can power it from lighting point.

Thanks in advance for any help.

 

[NozSpark]

You do not have to fit mains powered smokes when you change a CU, what you do have to do is make sure your main earth & protective earth bonding is up to scratch...

Smoke alarms can be powered off a lighting circuit, or off their own dedicated circuit,, however to comply with BS5839-6 they should not be powered from a circuit which shares it's RCD protection with a socket circuit..

So you are best off getting a high integrity CU which will have a couple of non RCD ways and stick them on a RCBO (if <50mm etc, etc)

 

[ianmacd]

Also if you power from a lighting circuit (as Noz says not sharing an RCD with a socket circuit) then it needs its own isolator too.

 

[vandalay]

Thanks for the quick replys,

I would rather not have to fit mains smokies at all as it will be a lot of messing laminates etc.

One more thing I forgot to mention now noz has reminded me about the earth. it is a TNS with a 16mm in aluminium going back to the sheath, would I have to change this to copper?

 

[ianmacd]

Not to the sheath. It should terminate at a MET (either externally or inside the current CU.

 

[PC Electrics]

Thanks for the quick replys,I would rather not have to fit mains smokies at all as it will be a lot of messing laminates etc.

One more thing I forgot to mention now noz has reminded me about the earth. it is a TNS with a 16mm in aluminium going back to the sheath, would I have to change this to copper?[/QUOTE]

Yes

If you fit mains smokes on any installation powered from the lights, then it is necessary to provide a means of isolating the smokes without cutting off the lights.

 

[ianmacd]

Thanks for the quick replys,I would rather not have to fit mains smokies at all as it will be a lot of messing laminates etc.

One more thing I forgot to mention now noz has reminded me about the earth. it is a TNS with a 16mm in aluminium going back to the sheath, would I have to change this to copper?

Yes

If you fit mains smokes on any installation powered from the lights, then it is necessary to provide a means of isolating the smokes without cutting off the lights.

Hold on. Thats the DNO' provided earth. You should not be interfering with it. They should present it to the MET and from there 16mm to CU if the MET is external. If not then put an external MET in and terminate both theirs and your new one in that.

 

[vandalay]

Hold on. Thats the DNO' provided earth. You should not be interfering with it. They should present it to the MET and from there 16mm to CU if the MET is external. If not then put an external MET in and terminate both theirs and your new one in that.

Sorry mate I worded that wrong , what I meant was the DNO earth goes to the MET and I will be going from MET to CU in copper this will be ok I would not have contact supplier to change it to copper.

 

[Andy™]

leave it. ali cable is used a lot on distribution

 

[vandalay]

Thanks, but just so I am clear on a CU change I would not have to install mains fed smokies.

 

[mikel]

don't have to change them. I used a consumer unit change for my last 2assessments and there were battery powered smoke alarms and it has never been an issue. In fact its never been questioned

 

[ianmacd]

Thanks, but just so I am clear on a CU change I would not have to install mains fed smokies.

Not for the CU change. If you are doing other building works that involve LABC they may require them though.

 

[Andy™]

Thanks, but just so I am clear on a CU change I would not have to install mains fed smokies.

your working to 7671, which does not require smokes being installed.

as ianmacd says, you may need to install them if other building work is being done to comply with building regs