On my last blog I shared with you the importance of having RCD protection installed and your home by a local electrician in Medway.
In this one I would like to a go little further and will try not to bore you with too much technicalities.
One of the changes that the 18th Edition brought on January 2019 is that it gave us the sign that slowly we are moving towards replacing the dual RCD fuseboxes with RCBO loaded.
Regulations 411.3.4 of BS 7671 states, the sum of the leakage currents shall not exceed 30% of the RCD residual current.
All RCDs on domestic installation must be 30ma this means that the total leakage current of the circuits it cover mustn't be more than 10ma.
But what the leakage current anyway?
Nothing is perfect is this life and electrical installations and appliances are no exception to this. By the way, this doesn't mean they are not safe. Because of this imperfection, small amounts of currents leak and flow directly to the earth, with the most affected circuits to be the one that feeds your kitchen appliance such as your fridge freezer, washing machine etc, and that becomes higher the older your installation and your electric appliances are.
Up until the end of 2018, if that leakage current was kept under 30ma there was no issue at all. Because the electrical safety constantly changes and becomes better and better the 18th Edition lowered that limit to 10ma as I wrote above.
Installing a dual RDC fusebox, especially in older installations, can easily now brake the electrical regulations and consequently be illegal.
RCBO stands for Residual Current operated Circuit Breaker with Overcurrent protection. And pretty much is your traditional circuit braker combined with an RCD. This means that every single circuit at your home has it's own separate 30ma RCD protection, and it not restricted by the 10% rule.
On a healthy electrical installation the leakage current to each circuit usually is about 1-3ma, well bellow the 30ma limit.
An RCBO fusebox will ensure that your electrical installation complies with the current electrical regulations but more important takes the safety of you and your loved ones to a higher level.
If by any means you are concerned about the safety of you electrics please call your local electrician in Medway to do a safety check.
I hope I haven't bore you with too many unwanted technicalities.
There is one more significant change that the 18th Edition brought to the protection of domestic installation and will talk about it on my next blog.