loop impedance value

[johnmf]

laying a new circuit from a 3 phase db.

its a swa run to a 3 phase machine. length of run is 40 metres, protection will be 150A bs88 fuses(big i know).

what is the max efli for the fuses? havent got my regs to hand.

bit worries the efli's going to be hard to get.

 

[RF Lighting]

according to my regs there is not a BS88 fuse rated at 150A


You have a choice of:

125A = Zs 0.35 ohms
160A = Zs 0.27 ohms

These values are for BS88 gG fuses with 5s disconnection time with a Uo of 230V.

 

[johnmf]

thanks rf,

sure ive seen a 150 before, might have been something else though!

cheers.