I seem to remember paying around £270 for the bits to do the consumer unit in this house, then found all type AC RCBO's.
The every installation shall be divided into circuits, as necessary, to reduce the possibility of unwanted tripping of RCDs due to excessive protective conductor currents produced by equipment in normal operation has been causing arguments since it replaced a separate circuit shall be provided for each part of the installation which needs to be separately controlled for compliance with the Regulations or otherwise to prevent danger, so that such circuits remain energised in the event of failure of any other circuit of the installation, and due account shall be taken of the consequences of the operation of any single protective device in 2008.
I have never seen how two RCD's could have ever complied, I have also considered two circuits is not enough for most homes, what we want is should anyone do something which causes a shock and trips the RCD then they should not unless actually working on the lighting circuit be plunged into darkness, so sockets and lights in any room should not be on same RCD and with sockets split side to side so even with a RCD failure no need for extension leads on the stairs, and lighting split upper and lower this can't be done.
However the big question is why anyone in rented accommodation should be doing anything which could cause that shock?
However with advisory on the two lighting circuits not having rcd protection, doing anything which would cause loss of lights where before there would be no loss of lights, does require some sort of risk assessment, when back in early 90's I fitted RCD protection at home, I also fitted an emergency light at top of stairs. Loosing light on the stairs I felt was dangerous, however stairs were centre of the house, here stairs have a window at top, still have a plug in rechargeable torch which will auto light with power cut, but not totally dark.
The talk about power supplies where electronics are before the transformer is spikes in supply can kill them so the need for surge protection devices and filtered sockets has been going on for years. The problem is no one can prove a spike caused the failure, but as a home owner even if under ground supply it seemed little enough to pay for the protection, but as to forcing landlords to fit it, not so sure.
Had the whole sale outlet not asked if I wanted one, I may have got a CU without one, but you can buy consumer units for £60 from
Screwfix, can't check details their site is down, but to my mind you want to ensure in 5 years time some one doing the inspection will not say who the heck fitted that, it needs changing it does not comply, so type A RCBO with SPD does seem way to go.
