type C Circuit breaker

[hsharp]

what is the answer to this question please?

A 16amp Type C CB used to protect a three phase reduced low voltage circuit is subject to a maximum Zs value of?

How do I work this out?

 

[Silly Sausage]

Well spotted Handy!!!
I reckon you're right there.

 

[D Skelton]

I think 0.4ohms. The question relates to reduced low voltage, which is a maximum of 63.5V line to earth. So, taking 1.44ohms for instantaneous operation at 230V line to earth, the value for 63.5V will be 1.44/230, x 63.5, =0.4ohms. Obviously, if the supply is lower than the maximum for reduced LV (not stated) then a lower Zs will be required. (Apologies for no line breaks.)

I think you're right. I'm gussing most of us (including myself) skipped the OP to chat about OSG Zs values vs BGB max Zs values.

A case of read the OP and definitely a case of RTFQ!