Rcbos Instead Of Replacing Cu?

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sam77

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Hi,

I'm not an electrician but have experience with microelectronics so have some idea of what's going on.  Had a electrical inspection on a rental property come back saying that everything was OK but CU would need to be replaced to bring up to latest standards.  I believe this is because the two lighting circuits aren't protected by an RCD (all others are).  From what I've read on here, I think just putting in RCBOs for those two circuits would satisfy the 17th and be cheaper?  The newish compact DP ones would seem to be ideal.

Thanks,

Sam

 
Wiring regulations do NOT reqiure you to update an installation whenever the regulations are updated.

What code has hi given that "fault" and has he given a satisfactory or not satisfactory rating for the overall installation?

 
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I assume that the installation was given a "Satisfactory" in the report that you've been given?

If so there is no need to add RCD protection to any of the circuits that currently don't. However for your own peace of mind you may want to.

If you only have 2 circuits that aren't currently RCD protected then there are a few options.

1. Replace the entire consumer unit

2. Replace the MCBs for RCBOs (might not be available for an obsolete consumer unit)

3. Add RCD protection for the circuits in an external enclosure

All of the above obviously have different costs to you 1 being the most expensive and 2 & 3 possibly being very similar

 
Thanks for the quick responses.

I haven't seen the report myself yet (going through agents) but was told that everything was OK which I suppose means that the report says 'Satisfactory'.  I should have been clearer in my post that changing the CU was suggested as optional work.

Ideally I'd like to have compact double pole single module RCBOs fitted but there only seem to couple of manufacturers (Garo, SBS).  How likely is it that these would fit a CU from 20ish years ago?

Thanks,

Sam

 
I can only speak about the SBS units.

From my experience....not a sniff, more chance of finding a straight politician!

SBS RCBOs are designed to fit on a double pole busbar system. In my opinion these are the dogs back wheels of RCBOs. They are a dream to use AND do exactly what it says on the tin.

Do yourself and the tenants a favour.....swap the board for a new SBS one.......I know it makes sense

Just promoting

 
Hi Sam,

If its 20 years old, it will probably be a 16th Edition board, which means it should have a DIN rail.

The set up could be, Main Switch, 2 x 6A (or 5A) MCBs, RCD + MCBs for all other circuits.

Easiest option would be to replace the 2 x lighting MCBs with  Standard RCBOs, assuming you can find a compatible one in terms of terminal height.

The other consideration would be the available height and room in the board, to accommodate the extra height and wires of the RCBOs.

Fitting Compacts would solve a space problem, but it would lead to busbar design problems.

If you want to start from scratch with a new board, hopefully you would take advice from TEF members and fit one of mine. If the existing board is in good condition and/or is difficult to take out, due to physical constraints, then you could strip the existing enclosure down to its DIN rail and fit all new Main Switch and Compact RCBOs (or Standard RCBOs for that matter). Needless to say, this is not a DIY job.

Incidentally, the only 2 Compact RCBOs on the market that will take LIVE in at the bottom, are SBS and GARO. Mine has a range of 6A - 40A and costs £13.00 + VAT. The GARO has a range of 6A - 25A and costs either £20.04 + VAT or £16.71 + VAT. If you go the full board upgrade route, you will almost certainly need 32A and maybe 40A sizes, which do not appear to be available from GARO. Hopefully, as a member of TEF, you would also favour SBS, since we are a TEF Sponsor.

SBS Dave

 
Not being qualified, I've never replaced an MCB so didn't realise quite how incompatible the brands are (despite looking similar) :(  

I do like the idea of RCBOs instead of dual RCDs.  What kind of price should I expect to pay to have a totally new 6 RCBO CU fitted?  The property is in Cambridge if that makes any difference.

Thanks to everybody for their help,

Sam

 
Unless SBS Dave has changed his policy,to use the SBS rcbo's you'll need the services of a qualified/competent electrician to purchase & install them, because unlike the DIY sheds & some other outlets who don't give a fig if you have a clue what you are doing with electrical installations; SBS will only sell to the trade (which in my book is a splendid idea!)

 
No change of Policy guys!

When I said it is not a DIY job, I inferred that it should be carried out by a qualified electrician, preferably a TEF Member.

Hopefully, SAM, someone will contact you to quote for the work.

SBS Dave

 
By the way SAM,

The reason it took me 7 hours to get back to you, was that I was out in Manchester all afternoon, shopping for a winter woolly.!!!

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Wiring regulations do NOT reqiure you to update an installation whenever the regulations are updated.

What code has hi given that "fault" and has he given a satisfactory or not satisfactory rating for the overall installation?
Pro dave is correct - IMHO a 16th edition set-up is perfectly adequate for rental purposes. Not having RCD protection on the lighting should be listed as nothing more than an observation, and could be argued as irrelevent because tennents should not be doing any works to the house anyway, not even banging nails in the wall to hang pictures. So in short, you do not need to upgrade to 17th edition, you certainly don't need to change the board, and if you want to get keen, alternatives methods of RCding the lights are available as discussed above.

My only argument for upgrading (apart from a desire to keep up with regs) would be an extra level of protection of your property against potential fire-risk caused by a lighting fault, but as the premises has tested OK, then even that is highly unlikely. As the premises has already been tested, changing the board should cost around £200 - £250 ie a new board with rcbos, and a half a days work to make a tidy job of it.

 
Interesting discussion on prices, as it's all been tested etc.

Well you can get a GOOD board easily for £100 (a cheap one for £50), and I would be quite happy to do half a days work for £150 making a total of £250  Even that would be a generous £37.50 per hour, more than I normally charge.

Anyone saying that it should be at least £350 total is expecting £250 for half a days work or £500 a day, which translates to £62.50 per hour  It's no wonder we have such a bad reputation and people try and do things themselves. 

Not having a go at anybody, just making an observation :coat

If I could get away with charging £62.50 per hour then I would love to, but I expect I would get very little repeat work and very few recommendations and would probably be out of business very quickly.

 
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PD,

That depends on where the job is though.

If you are doing 4 hours on site, and, it takes you an hour to get there & back, then that eats into your money pretty quick.

Plus you have to warranty the parts, so there has to be a margin in for that.

Take yesterday, I did 6 hours on site, but, it took me 4.5 hours to get there, if you think I'm driving over 200 miles for 4.5 hours for nowt, forget it, it has to be paid for.

Plus it depends on what board you are going to fit, whilst the circuits have been tested, will the wiring be long enough to reach, what is the access to the board like, will you have to park half a mile from the job & walk back and fore, etc. etc.

As an aside, I know someone up in AndyTM's neck of the woods who had to pay £75 per hour for a plumber 5 years ago!

 
Well i have just seen a quote from CHUBB who want over 200 quid to change 2 heats to smoke detectors.....standard Apollo detectors. 250 quid to fit andp isolator and FP200 supply cable to THEIR fire panel.....distance?...........300mm!

Woman down the road paid £17 per lamp to have some lamps replaced. She supplied the lamps and the Spark lived about 2 minutes away. Standard GF flat, 2 rung steps required, 10 lamps were changed!......serves me right for not advertising I suppose!!

 
I didn't quote SAM a price, but it is easy to estimate the price of an SBS DB, with 6 x Standard RCBOs and 2 spare ways. It is less than £100.00 inc. carriage and VAT. Even cheaper if you use the existing enclosure and repopulate with my Main Switch and RCBOs. That's the known bit.

The unknown bit is the labour and travel, I & T , etc, but that could be minimised by using a local electrician and there must be some TEF members in the area.

SBS Dave

 
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