What does voltage rating of circuit breakers imply?

DIY
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1

Hello everyone,

This appears to be a very basic question but responses reach opposite conclusions. Is the voltage rating on circuit breakers (ue) a maximum or a requirement? What will happen if I use a 400/415V or 690V breaker (those are the only MCCBs I can get in my market) in a 230V AC circuit?

Some sources say that will work because the breaker voltage exceeds my circuit voltage. That the MCCB will trip safely at any voltage below the MCCB rating. Others disagree. They say the MCCB will never trip because my circuit voltage is lower than my MCCB voltage.

What gives?

As background, I want to use 3-pole MCCBs on the AC side of my Victron rig.

F.

2

The voltage rating has to do with maximum tested breakdown voltage, arcing, etc. MCCBs are over-current protection devices (OCPD) and trip on current via thermal and/or magnetic (inductive) loads. You can use a device rated for higher voltage in a lowe voltage circuit, but not the other way around.

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3

That makes sense, thank you.