Requirements for external fuse

[Cicero]

Hi there,

I'm designing a product which has an internal battery, and I'm using a SCP-35-12 PSU https://www.mouser.co.uk/ProductDetail/Mean-Well/SCP-35-12/?qs=AmzscSOM9Zbf9CqcaRL6sQ==

I'm wondering though, and I can't find a definite answer in terms of safety requirements docs, whether I absolutely have to have an external accessible fuse on the chassis? The PSU does have a built in fuse already, but it would require a technician to open the machine, and change it should it go for some reason.

Hoping one of you fellas just know off the top of your heads, I'd really appreciate it.

 

[kubeek]

I am not sure about the definitive answer, but everything comes down to safety of the person changing the fuse. If the voltage is low enough to be safe, or everything is shielded enough so that you cannot come into contact with the high voltage, then I guess you should be ok having it inside.
Since it is battery powered, the current can be quite high and you might need protection covers against short-circuiting the battery even if the voltage is safe.

 

[Nigel Goodwin]

Hi there,

I'm designing a product which has an internal battery, and I'm using a SCP-35-12 PSU https://www.mouser.co.uk/ProductDetail/Mean-Well/SCP-35-12/?qs=AmzscSOM9Zbf9CqcaRL6sQ==

I'm wondering though, and I can't find a definite answer in terms of safety requirements docs, whether I absolutely have to have an external accessible fuse on the chassis? The PSU does have a built in fuse already, but it would require a technician to open the machine, and change it should it go for some reason.

Hoping one of you fellas just know off the top of your heads, I'd really appreciate it.

I would suggest not, particularly as a UK product it will have a fuse in the mains plug.

Even more so, there are a GREAT many products which don't have replaceable mains fuses at all, not even by a technician.

 

[Cicero]

Ok cool, to be honest I didn't want to put an external fuse. There are a few internal ones so I felt it would be redundant anyway.