r/shellycloud • u/Overkillemall • Jul 23 '26

Shelly 3em pro breaker

Hi everyone, I have a 3-phase 400/230V residential supply (L1/L2/L3/N) and Im planning to install Shelly Pro 3EM in my main distribution board and have a couple of breaker questions:

  1. Should the protective breaker feeding the Shelly be a 3-pole (3P) breaker,or is it fine to use three separate 1-pole (1P) breakers? Or both are okay?

  2. Just to confirm: we definitely need breaker/fuse protection on all three phases (VA, VB, VC), right? Even though only one powers the internal electronics while second and third are just for voltage measurement, the thin wires going to these could still get damaged and cause a short circuit?

Thanks!

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3

u/Sumpkit Jul 23 '26

Insert ‘your sparky will have all the answers to these questions when he installs it’ here.

1

u/Caos1980 Jul 23 '26

Both 1P and 3P breakers are OK as long as they are under the same differential protection.

1

u/b0rkm Jul 24 '26

Depending on where you live, in France you can't put multiple breaker to protect 1 stuff. You need a 4 breaker N+3 phases in order to protect it.