How to add RCD protection

[DIYWell]

One of the C3 observations in an EICR was that there was no RCD protection on this consumer unit.

Is adding one as simple as replacing the main switch or another module, or does it take a whole new consumer unit?

 

[Taylortwocities]

It rather depends.
Replacing the main switch with an RCD is bad engineering and not recommended because a fault on any one circuit will cause the main RCD to trip, cutting off the power to the whole house.
The MEM MCBs that you have can be converted to RCBOs by adding a conversion pod to each MCB. But at more than £70 a circuit this is not a cheap option as a whole new consumer unit with multiple RCDs shouldnt be much more than that.

So the best option would be to have someone change the consumer unit. Is there a reason why you need to do this? The EICR should have mentioned the lack of RCD protection as a C3 - improvement recommended.

 

[DIYWell]

It was just that; a C3. If it were a very cheap fix I'd have it done, but replace MCB just to tick off a C3 is not worth it in it's own right.

 

[Taylortwocities]

Regulations are not retrospective, so there is no compunction to bring an installation up to date when a new version of the regs is issued.
New work does have to comply, however. So you will have to add RCD protection, at some point, if that is needed for new things that are being added.

I would consider adding RCD protection for sockets that are likely to be used for outside use.

 

[Risteard]

The EICR should have mentioned the lack of RCD protection as a C3 - improvement recommended.

The EICR shouldn't have mentioned "lack of RCD protection on the distribution board" as there is no such requirement.

It should have highlighted various reasons why RCD protection would be required, and it is very likely that these would not all attract merely a C3 recommendation against them.

 

[EFLImpudence]

The EICR shouldn't have mentioned "lack of RCD protection on the distribution board"

Especially as it's not true.

 

[securespark]

Strictly, "lack" can mean "absence" but it can also mean "not enough".

 

[EFLImpudence]

I suppose so.

 

[ericmark]

Strictly, "lack" can mean "absence" but it can also mean "not enough".

I see your point, clearly there is one RCD but we have no idea what it protects or it's size. From the emergency lights and sump pump labels the latter seems to be supplied from a 16A RCBO it would seem this is not domestic. Once we move to industrial supplies we need to consider who is in charge, it may have an electrician and it could have surface cables and RCD's at the destination rather than origin.

There is nothing wrong with surface or permitted cables like the Ali-tube from feeding RCD sockets, the RCD does not have to be in the consumer unit. In the main where and how RCD protection is installed is down to cost, both in the actually installing and the loss of production. With a work bench having RCD sockets so if one is tripped it does not impact on work being done by a co-worker may be considered worth the cost as it increases work output.

I find it interesting even with domestic that fitting RCD sockets can be done by DIY but fitting them as part of a consumer unit is due to Part P requirements on notifying not really cost effective for DIY. It seems crazy but a DIY person could fit a row of RCD's after each MCB without requiring to notify.

At around £20 each for twin pole RCD and £20 for a RCBO adding after the MCB is the same price as adding in the consumer unit. Plus £25 for the enclosure so in real terms cost of parts to fit a new consumer unit with all RCBO is the same as adding RCD in separate box after the consumer unit. For an electrician it would be a crazy idea, but for the DIY guy it removes the requirement for notifying as no new circuits and no consumer unit.

This is where Part P becomes daft as it is a distribution unit, but not a type tested consumer unit. As to if one is allowed to use a distribution unit in domestic is another point, I seem to remember BS7671:2008 states that where ordinary people are in charge it needs to be type tested but BS7671:2008 is not law. And if some one has enough knowledge to do the work then not really an ordinary person.

Personally I would swap the consumer unit, it's so much neater, and I would not worry about Part P as long as it is safe. However I have lived in the house well before 2004 and it would be hard to date when I made the changes, the EICR clearly dates when the installation was in a certain state so easy to show work was post 2004. Although work planned before 2004 does not need Part P so I have loads of plans, just never got around to doing them.