ᐅ Chases in Poroton T12 blocks

AOLNCM schrieb:
You are right, and I was wrong.

It’s good that several sockets were installed; most multi-socket outlets are only rated for up to 3500W.

I was aware that the resistance depends, among other things, on the length of the cable. Thanks for that.

The number of sockets is not the deciding factor for the permissible limits. The living area determines the number of electrical circuits for lighting and sockets in a residential building. Up to 50 sqm (540 sq ft) two circuits are sufficient.

I don’t know why your stair lighting was wired back and why 16A and 1.5 mm² (16 AWG) cable weren’t considered. Most stair lights are LEDs with about 1W power consumption. I wouldn’t recommend more than one LED per meter (3 ft) anyway, as it gets too bright at night in the stairwell.

Of course, you’re right that you shouldn’t save on electrical work, insulation, or other building materials. Everyone should keep their budget in mind, though whether they oversize one or several trades is up to them. If there are special reasons for that, then why not.

Separate circuits were installed for my washing machine, dryer, and hairdryer.

Um, objection. My electrician told me that you don’t protect the few watts connected by the devices, but the cable itself!

In other words, if you have a short circuit because the cable got pierced, the current that flows depends on the contact resistance between the two conductors—6, 16, or 20A—until the breaker trips. And with a long thin cable with COMPARATIVELY high resistance, there’s quite a voltage drop and thus less power.

That was my initial misunderstanding, too. I thought since I’m only connecting LEDs, say a maximum of 50W in the bathroom, the cable rating would be fine, and I could protect it with a 16A breaker.

I installed the cable in the stairwell myself; it was easiest to chase that way and probably the most efficient option. We have a double-helix staircase, so one side goes up and the other down...

The lighting uses 1.5 mm² (16 AWG) cable with 6A breakers, which is definitely sufficient for LED lights...

He must know what he did.

There is a so-called "trip curve for circuit breakers," where the trip time depends on the multiple of the trip current.
For a 20A fuse, this value is naturally higher than for a 16A fuse, which makes the fuse less sensitive.
You probably have a few RCDs (residual current devices) installed.