May seem like a stupid question but I have come across a number of commercial installs such as offices, sports centres etc where the installer has used steel conduit which is embedded into the building fabric. As a result rcd's/rcbo's are not generally required on the lighting circuits.
I'm trying to work out why they wouldn't just plaster over the cables and fit an RCD or rcbo to the circuit. Surely it would be cheaper than using steel conduit everywhere.
The only reasoning that I can think is that if that there would be much less disruption caused if someone drilled through a cable and also by not fitting an RCD/rcbo it alleviates the problem of nuisance tripping.
I'm trying to work out why they wouldn't just plaster over the cables and fit an RCD or rcbo to the circuit. Surely it would be cheaper than using steel conduit everywhere.
The only reasoning that I can think is that if that there would be much less disruption caused if someone drilled through a cable and also by not fitting an RCD/rcbo it alleviates the problem of nuisance tripping.