Anyone else think this is a daft CU configuration?

[Murdoch]

Given its a medical facility with lots of equipment being used most of the time?

 

[Andy™]

whoever done that was probably cheaper than those who quoted from an RCBO board... usually the customer is just as much to blame for going wth cheapest...

 

[kerching]

Same as that domestic job I saw last week. Who fits a split board nowadays? I wouldn’t fit one in my garage
If it’s medical does it come under MEIGAN?

 

[Murdoch]

Same as that domestic job I saw last week. Who fits a split board nowadays? I wouldn’t fit one in my garage
If it’s medical does it come under MEIGAN?

Split boards should have been outlawed when metal units became the norm again

Going to be fun changing a relatively new split board to accommodate AFDDs

 

[kerching]

Going to be fun changing a relatively new split board to accommodate AFDDs

I encountered my first AFDD board yesterday, in a sheltered housing scheme. Each resident owns their own flat with bathroom and lounge kitchenette. However there is an on-site live in manager and meals are provided in a communal dining room if they want to join in, all run by a charity. It was a LEWDEN board

 

[Murdoch]

I encountered my first AFDD board yesterday, in a sheltered housing scheme. Each resident owns their own flat with bathroom and lounge kitchenette. However there is an on-site live in manager and meals are provided in a communal dining room if they want to join in, all run by a charity. It was a LEWDEN board

I encountered my first AFDD board about 1.5 years ago in the student house my daughter was moving into - AFDD's for all circuits - a bit OTT to say the least.

Still not encountered any locally and the only 1 that I quoted to fit .......... never heard back from the LL

 

[runningpiglet]

Given its a medical facility with lots of equipment being used most of the time?

View attachment 16714

To my mind the biggest problem is that all the lighting circuits are on the same RCD - should have split the lights across both RCDs

 

[Murdoch]

To my mind the biggest problem is that all the lighting circuits are on the same RCD - should have split the lights across both RCDs

Should never have fitted a dual RCD board in such an installation

 

[Andy™]

To my mind the biggest problem is that all the lighting circuits are on the same RCD - should have split the lights across both RCDs

probably because the RCD's would trip if one MCB on each side

 

[johnb2713]

Im taken aback with the responses on here with regards to dual RCD boards. I totally get it that RCBO is preferable but why is dual RCD such a bad thing? It doesnt really seem to be a hanging offence to me.

 

[kerching]

Im taken aback with the responses on here with regards to dual RCD boards. I totally get it that RCBO is preferable but why is dual RCD such a bad thing? It doesnt really seem to be a hanging offence to me.

Purely my opinion but, and I don’t quote reg numbers as life is too short, there are regs that say

Design and install to aid testing and fault finding

Design and install to minimise inconvenience……minimise means reduce as far as possible to zero. Two RCDs don’t minimise the issue the only halve it

A fault on one circuit should not influence another circuit……all circuits fed via RCD are lost when RCD lifts

As said before, my opinion only , BUT I would never fit a split board. There is also the 30% issue

 

[Murdoch]

It’s questionable if dual boards actually meet the regs

 

[binky]

Im taken aback with the responses on here with regards to dual RCD boards. I totally get it that RCBO is preferable but why is dual RCD such a bad thing? It doesnt really seem to be a hanging offence to me.

at one time RCBOs could be £35 or more each, but with the introduction of basic brands such a Lewden and Control gear where RCBOs are more like £15 each, the cost of a full board of RCBOs dropped signifiantly, and therefore the reason not to fit them, ie cost. That, and a long discussion that concluded years ago that dual RCD boards don't meet the requirement to mimimise the inconvenience. So to us, on this forum, installing dual RCD boards is just poor practice that professional electricians should not even consider.

 

[SPECIAL LOCATION]

Im taken aback with the responses on here with regards to dual RCD boards. I totally get it that RCBO is preferable but why is dual RCD such a bad thing? It doesnt really seem to be a hanging offence to me.

Labour costs fault finding on dual RCD boards are generally much higher than on a fully equipped RCBO boards, due to greater time needed to investigate and resolve a problem....

So over a typical lifespan Dual RCD CU's can be a much more expensive and very inconvenient solution.

e.g. when a customer loses power to multiple circuits, and may be unable to restore power due to a neutral-earth fault they cannot resolve... and its the weekend... and they can't get a same-day fault investigation response from any local electricians, a full RCBO consumer unit may look like a much better less inconvenient solution!

Its a bit of a sod when a faulty fluorescent strip light in the flat roof garage knocks the power off the freezer socket circuit due to a leak in the roofing felt while you are away for the weekend.. (That scenario is not made-up!!)

And.. I have attended numerous such faults since commencing self employment back in Feb 1999!!

Our local neighbourhood social media sites regularly have questions from persons who have lost all, or part, of their power due to multiple circuits via single RCD consumer units..

I really cannot understand why any competent knowledgeable person would recommend such a poor solution..???
(unless you are just looking to rip-off a poor unsuspecting customer, make a quick buck, and ride off into the sunset offering no future service, support, fault response etc.. {possibly with your cowboy hat on})

No, you are quite correct it is not a hanging offence...
But just a very very very poor solution to a problem....
When much better solutions are easily available for minimal extra cost..

Basically its like putting budget/economy tyres on your main family car that needs to tow a caravan plus carry you and your kids around Europe for two weeks on you summer holidays.. Its just asking for trouble!!!!!!!!!!!

Not illegal, Not a hanging offence, Not against trading standards, Just very poor design!!!!!

Current wiring regs... 314.1, 531.3.2 (ii), 531.3.4.201, 531.3.5.2 give varying guidance relating to RCD's, RCBO's, Unwanted tripping, Multiple MCB's via one RCD, and RCBO's used in residential installations...

But the basic common sense approach from all of these reg's, is that individual RCBO's are the preferred solution for a domestic dwelling!

 

[johnb2713]

Thanks everyone for the reasons not to use dual RCD, I accept totally RCBO is the way to go but I also feel dual RCD is a small improvement over single RCD and some of your responses are just a tad dramatic. I agree in this day and age they’re not a good item to use.

 

[kerching]

@SPECIAL LOCATION that’s what I was just about to say

 

[Geoff1946]

Whist not disputing the advantages of RCBOs, all the fault finding advantages can be met by using dual pole MCBs.
A few years ago I had the dubious privilege, (whilst on holiday!), of solving an earth fault problem at a relative's property in France. This was fitted with dual RCDs and two pole MCBs, which made the task far simpler than an equivalent UK setup.

 

[Murdoch]

Whist not disputing the advantages of RCBOs, all the fault finding advantages can be met by using dual pole MCBs.
A few years ago I had the dubious privilege, (whilst on holiday!), of solving an earth fault problem at a relative's property in France. This was fitted with dual RCDs and two pole MCBs, which made the task far simpler than an equivalent UK setup.

The French rules and set ups do allow for more straight forward fault finding.

People having dual boards fitted now will be in for an expensive update when AFDDs are mandated for socket circuits

 

[Luckyboy]

Haven't fitted a dual split board for a long time, only do full RCBO boards with SPD fitted. If they don't agree to that, they can go elsewhere IMO. Any time I've seen a recently installed dual split board, the install has been shoddy - likely because it's been fitted the by a builder, not an electrician.

I have fitted a number of AFDDs, mainly in HRRBs and HMOs. Haven't had any callbacks yet but the thought has crossed my mind a number of times - what do you do when an AFDD trips because of an arc fault? Short of rewiring the circuit? Are there any tools available to help trace such a fault?

 

[Luckyboy]

Given its a medical facility with lots of equipment being used most of the time?

View attachment 16714

Another thing, how much extra time would it take to actually label the board appropriately or have a schedule nearby. I hate it when I come across a board with "sockets" on so many MCBs, it means almost nothing!