32amp c curve breaker

[Adam Marshall]

Is it possible to put a 32amp c curve mcb on a circuit board with a 80amp service fuse on supply in

 

[WorkshopChris]

Yes providing that all the cabling and earthing arrangements are looked at.

 

[Adam Marshall]

They are yes was thinking the service fuse would blow before mcb

 

[Spark plug]

How would an 80a fuse blow before a 32a mcb?

Depending on fault conditions a 32a Mcb would probably blow before a 20a fuse

 

[Adam Marshall]

But if I put a welder on this won't it draw more than 32amp on inital switch on

 

[WorkshopChris]

As a example if your 80a fuse is to BS88-3 it will pass a peak of 1100a and 650a for 1 second and 430a for 5 seconds,
in comparison a c curve 32a will pass 320a for 5 seconds.

 

[Adam Marshall]

Workshopchris so it will be OK?

 

[WorkshopChris]

If you are using a 32c type your 80a upstream will be fine.

 

[brightspark]

why wouldn't it be ok whole houses run on 80 amp incomers working sockets emersion heater shower and cooker and lights. diversity

 

[WorkshopChris]

At work in the winter i see 100a fuses sitting at anywhere around 90/110 amps for hours often days at a time without any problems even tacking into account peak starting loads well in excess.

 

[brightspark]

At work in the winter i see 100a fuses sitting at anywhere around 90/110 amps for hours often days at a time without any problems even tacking into account peak starting loads well in excess.

same here seen meters burn of the wall before the fuse went

 

[Adam Marshall]

This is on my house consumer unit sorry I forgot to put that