Do i need to change my consumer unit?

[Blakums]

Hi, I am about to get a new kitchen installed and when the tradesmen came to survey it they said the consumer unit will need to be changed. I have attached a photo of my unit, it is old but still works perfectly so why would i need to change it? Thanks for your replies.

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[flyingsparks]

You have no RCD protection. New circuits installed or altered will need this so often the easiest way is new CU. also you have no spare ways available so there again if new circuits are to be installed then that would be the best option. It's not essential, there are other ways around it, but by far the best thing to do is change the CU in your circumstances I would say.

 

[Taylortwocities]

From the age/look of the CU, I would guess that your earthing conductor and main protective bonding conductors will also need to be upgraded.

 

[RF Lighting]

IIRC those old Dorman Smith circuit breakers do not have a magnetic trip and rely on thermal overload only, so should be replaced as a matter of course anyway.

Now is the perfect time to do it whilst you're having other electrical work carried out, and will make it so much easier to ensure your new wiring is safe and compliant with the wiring regs.

 

[PrenticeBoyofDerry]

The logical step would be to have a new consumer unit fitted, as any newly installed sockets and very likely newly installed cable(buried within wall), will require the added protection of RCD.
The only other sensible option would be to have a separate unit for the new work in the kitchen.
You used the term tradesman, can we take it this tradesman is a suitably qualified, registered electrician? As this work requires building controls notification and an electrical installation certificate (including schedules of inspection and test results). Don't fall into the trap of employing someone who can not perform these tasks! So ask some questions about their credentials and do some research to confirm this.
http://www.competentperson.co.uk/

 

[ericmark]

The old Loadmaster Dorman Smith was a well made unit I used them a lot on the building of Sizewell Power Station 1990's but there is no way to add RCD protection within the unit and the only alternative is to use a distribution unit for the kitchen which will need feeding. Although 50A Loadmaster MCB's were made to get one now would likely be a problem to feed the kitchen distribution unit and it would need feeding with one of the special cables the only reason to do this would be where the house as a whole needs a re-wire and the electrician will not change the board without doing whole job.

With this in mind you will need an Electrical installation condition report before the consumer unit is changed and according to that report decide on the way forward. Clearly this needs a man with some skill not the kitchen fitter.

To jump in and change a board without first testing could mean a lot of un-secluded work it could of course go without a hitch.

 

[Adam_151]

IIRC those old Dorman Smith circuit breakers do not have a magnetic trip and rely on thermal overload only, so should be replaced as a matter of course anyway.

Not so: http://www.dormansmithswitchgear.com/tec_support_downloads/mcb/Loadmaster_datasheet.pdf

they do have a magnetic release, however its set quite high, for example need a zs of about 0.35 to trip a 30A on magnetic trip, however there is a published max zs of 0.63 for 0.4sec disconnection, however if you study the data you will see that this is relying on the thermal element (which is perhaps where the mis-conception comes from)

That is much worse than a re-wireable fuse! , if you do the adiabatic with 360A and 0.4 sec you get a minimum cpc of 1.97mm². These boards were around at the same time as 2.5/1 twin and earth as well!

There was a revised version called series 15 that had a wider toggle and 6/16/32 ratings rather than 5/15/30

 

[Blakums]

Thank you all for the replies, i am going to get the unit changed. It cant hurt anything other than my wallet! Thanks again.