RCD or RCBO consumer unit

[EricMark]

Step one, measure the leakage, I have 8 mA spread between 14 RCBO's after losing two freezers full of food, not taking that chance again, my freezers are supplied from the UPS with RCD sockets, so likely tripping is unlikely.

But guessing is not the way to go, you look at background leakage, then decide.

 

[mainline]

View attachment 121156 Step one, measure the leakage, I have 8 mA spread between 14 RCBO's after losing two freezers full of food, not taking that chance again.

There's always a chance of a rcbo tripping, even when there's nothing wrong with the installation or appliance.

 

[Teddy Lop]

Sorry I don't mean to be that person on the Internet, maybe there's something unsaid or I'm being cynical, but I'm puzzled how someone who installs distribution equipment would not be familiar with RCBO v Dual RCD pros&cons?

Dual RCD's are wretched things and I always felt a bit dirty when fitting one, I'm told the "they" never envisioned such a thing and were anticipating greater use of RCBO's but due to their failure to anticipate the market looking for loopholes to find cheaper solutions (especially with overblown complex wording of rules where simplicity would suffice), the dualies quickly materialized and the they permitted their use in preference to admitting they could have done their job better.

With the low cost of RCBO's today they're a no-brainer, but even before on small installs they didn't add much more, and as you go larger the benefits of RCBO's only become more prevalent. The dual sweet spot (if such a thing can be said to exist) was probably 3-5 circuits per RCD, as you sail past that you're stretching the obligations for things such as minimisation of nuisances IMHO.

I explain the benefits of RCBO to every prospective client and 95%+ are happy to pay the extra, most dualies i fit are builder or landlord insistence, and most of the clients I talk to about their dualies, particularly when doing a bit of fault finding, are chagrined at never having had an explanation or the option!