I've just bought a 4th floor apartment in an old (1820) building in Spain. Neither my apartment, nor the building as a whole, has any earth circuit.
I'm looking for practical, technical advice on what steps I can take to minimise risks of injury or equipment damage caused by this arrangement. Longer term, can anybody suggest what installing a building ground circuit would entail? My apartment backs onto a small service courtyard (called a "patio" here), so for example, it's relatively easy for me to run a cable to ground level.
update…
The service input goes to an old Siemens schutzschalter which is labelled as 30mA. The output of the Siemens goes to a single 20A circuit breaker which then feeds all of the lights and sockets in the apartment.
Pressing the Test button on the Siemens has no effect, so I'm guessing that's not giving me a whole bunch of protection. Since it's wired directly to the supply, it will take time to organise the electricity company to intervene. Therefore, is it reasonable for me to add a second RCB (https://www.bricodepot.es/productos/electricidad/proteccion-electrica/proteccion-modular/diferencial-bipolar), alongside the breaker to provide the RCB protection? There is ample space in the consumer unit for it.
I should also explain that the whole apartment is scheduled for renovation, including rewiring. Thus I'm looking for what I can do quickly to address any safety issues for the interim.
Existing
mains ===> Siemens ===> 20a breaker ====> lights and sockets
Proposed
mains ===> Siemens ===> New RCB ===> 20a breaker ====> lights and
sockets
Best Answer
Look in your electrical panel and see if you have any combined residual-current / over-current breakers. And check to see if any of your wall receptacles are residual-current receptacles.
Depending on the wiring arrangement in your apartment it might be cheaper to use residual current device receptacles for the ground fault/residual current protection. One RCD receptacle properly placed would protect the entire circuit downstream.
On the other hand, the easiest thing would be to replace each of the over current breakers with a combined residual-current/over-current circuit breaker. If you have a single master breaker for the apartment, you could replace that one breaker with a combined breaker, but if you then have a ground fault anywhere, the power for the entire apartment would be cut off. This would be very inconvenient.