Fitting new boiler, do plumbers worry about type of RCD fitted?

[ericmark]

I note some new boilers, Bosch for example state should be protected with a type A RCD, when the house has a type AC RCD or RCBO as plumbers what do you do?

Interest only as I realised I had made an error and fitted type AC RCBO's instead of type A, I will swap 2 to type A, but rest will be left.

So do you just ignore what type is fitted.
Do you advise the owner they need changing.
Do you not fit the boiler until changed.

Or some thing else?

 

[Gasguru]

I guarantee 99% of installers won't have a clue about the different characteristics of RCDs, I guess those that have their electrical qualifications are aware.

From what I can see it's a shambles and considering all the high efficiency electronics we now have why are the older spec RCDs still being sold?

TLC don't even mention the different types, Screwfix sell a variety.

There is no consistency between the manufacturers whether to even print the appropriate symbols on the RCD to show the type.

Worcester say Type A must be used but Viessmann recommend type B...what a farce.

The unintended madness of the EU unabated drive towards energy efficiency...boilers now have switching power supplies for the main pcb, fan and pump.

In theory modern electronics can result in the RCD sensitivity reducing on the older RCD designs hence the new designations.

 

[mcmoby69]

Not happening at mine for a while. Fook that.

 

[ericmark]

When I ordered my consumer unit and RCBO's they came clearly marked type B, I thought good, type A would have been good enough, due to circumstances I got some one else to fit it, and when I came to look the logo showed

today I phoned up supplier, and asked if they had any type A in stock, answer was only type B so asked what the logo looked like told it was

so they had also made same mistake so they phoned supplier fuse box and a pair of type A 32A curve B are on order logo should be

as to type F

and type B

I am told you can't buy RCBO of that type with standard single module width, so if Viessmann recommend type B

it would seem some one in Viessmann has made same mistake as both my suppliers and I and read the curve rather than type. I far as I am aware only solar panels and electric cars ask for better than type A.

The John Ward video

is quite an eye opener as to what happens using type AC, in my house with a PME supply we don't really rely on the RCD, but in houses with a TT supply disabling the RCD is rather a serious thing, as to fitting 300 amp type B for whole house to counter if any are disabled it seems a backward step, the whole idea of the RCBO is so any fault is not going to affect all circuits, when my roof leaked only one socket circuit tripped the rest of the house was unaffected.

So type A now ordered for my cooker and kitchen sockets with an induction hob and two freezers plus washing machine with inverter control those two circuits have reasonably high powered devices using inverters, rest of house, 14 RCBO's going to take a chance.

However it is all well and good for myself who knows the risks to make an assessment and decide how far to go changing RCBO's, but for a tradesman working in some one else's house that is very different, when the Emma Shaw case was publicised my thoughts were they by the grace of god go I. I would not have hesitated to send my electricians mate with a earth loop impedance meter to test a set of sockets, after all what's so hard, plug in, press button, record the result, even if that result is OL, and if I got OL then I would investigate, there is no way I would have even considered that a semi-skilled guy would going into the works canteen and fudge up some results.

I can see in the future fitting of type AC RCD's coming back to bite the trade, which is far enough for electricians they should know better, but for heating engineers and plumbers the question is like with the Emma Shaw case should they be connecting up the electrics? And what would the courts say if a TT supply RCD fails to work because of the boiler being faulty?

So interested to see what plumbers think, and do, I would have thought a note i.e. must be in writing, that the RCD should be changed after fitting this boiler is a get out of jail free card for the plumber. As long as he tells the client the new boiler needs a type A RCD then it would be good enough, but the Viessmann recommending type B puts another complexion on the problem, as if you can't buy a type B, how do you get around that? Saying to a client you will need a henley block and a mini consumer unit to feed this boiler is going some what OTT.

 

[ericmark]

Not happening at mine for a while. Fook that.View attachment 200554

My old house also has the old Wilex boards two of them with two RCD's feeding the whole board. just because it has an old Wilex fuse board that does not mean no RCD protection, those went in around 1992 so over 25 years, and they are that old not marked as to what type they are, which clearly causes another problem, if not marked how could anyone advise the customer?

I would say as a Plumber one only expects level 3 qualifications so can't see a court blaming the plumber, but as an engineer as with heating and ventilating engineer one expects a level 5 qualification or above, otherwise should not call ones self an engineer, and I would think courts would expect anyone calling himself an engineer to know the installation was not suitable for the boiler.

 

[JohnD]

This cropped up recently. My MEM/Eaton RCBOs are type "A" but are very expensive.

Screwfix and others sell a somewhat similar one at a third or a quarter the price, but it is type "AC"

It took a bit if burrowing to work that out.

 

[ericmark]

I have looked at Screwfix and they are not alone in not putting in the type, it says curve type B with the Wylex if you look at the picture is shows type A. With BG shows type AC but specification say nothing. So people don't even consider the type. So whole sale outlets have started using type and curve but very few.

But as said until some thing goes wrong, no one seems to worry, the big question is when it does go wrong what will be the outcome? They always blame some one, but who? I have looked at best practice guide for the electrical installation condition report. And nothing.

131.6.4 The installation shall have an adequate level of immunity against electromagnetic disturbances so as to function correctly in the specified environment. The installation design shall take into consideration the anticipated electromagnetic emissions, generated by the installation or the installed equipment, which shall be suitable for the current-using equipment used with, or connected to, the installation.

515-02-01 The immunity levels of equipment shall be chosen taking into account the electromagnetic influences that can occur when connected and erected as for normal use, and taking into account the intended level of continuity of service necessary for the application. See the specific standard or BS EN 50082.

So it is covered by regulations and has been for some time, but it is rather vague. Point is the equipment which stops the RCD working may not be the equipment which has the earth leakage and in the best practice guide it says

All references to RCD protection mean additional protection by an RCD having a rated operating (tripping) current (IΔn) not greater than 30 mA.

No where does it refer to type, and it says in the main "absence" it does say "The main RCD or voltage-operated earth leakage circuit-breaker on a TT system fails to operate when tested with an instrument or integral test button." but there is nothing to say how the RCD should be tested.

I have always been told to as far as possible not to have any equipment running when testing the RCD, which makes a lot of sense, you do 6 tests, that is three tests with positive and negative, one shows does not trip under 15 mA, one shows it trips at 30 mA but allowed quite a long time think 200 mS and last at 5 times so 150 mA it must trip in 40 mS, but this is always done after telling people to log off there computers etc, so it is unlikely to be picked up during testing. And there is no requirement to even issue a code 3 because type AC fitted when should be type A or better.

Who reads the instructions fully, you read the sections which may change, there is so much waffle in manufacturers instructions that most people only read the bits they need to.