Dave Plowman (News) wrote
Fredxxx wrote

As usual, you miss the point entirely. Why fit fuses - where there's no
fire risk - if there is no method given for replacing them in service?

Why, so that a potential fault doesn't cause a fire. Making the
fuse a serviceable item, doesn't remove the original fault.

A good example is here;
http://www.vauxhall.co.uk/zafiracustomeradvice.html

There is no high current source on a boiler PCB, unlike a car.

Irrelevant to whether a couple of pico fuses can be useful to
prevent anything catching fire when something fails and making
it much harder to fix than just by replacing the pcb when it fails.

The mains side has a user replaceable fuse.

Which wont necessarily prevent something catching
fire if something on the pcb or which is wired to it
fails, so you can't JUST replace the pcb when it fails.

I've had a couple of dimmers fail recently - after a
halogen bulb has failed and shorted for an instant.
Just burnt out a track on the PCB - no fuse there.

Sure, but those are much cheaper pcbs than you get in a boiler,
so those pico fuses may not be economically viable with those.

Different with a much more expensive boiler pcb where the
extra cost of a couple of pico fuses is bugger all in the total
cost of the pcb and so worth having so that you can be sure
that however it fails, you can always just replace the pcb
without having to clean up the mess that was produced
when the pcb caught fire without any fuses to stop that.

If the PCB is scrap after any fault, a
cheaper way of doing it than PCB fuses.

But nothing like as good at preventing the pcb itself
catching fire on a component failure and making it much
harder to just swap the pcb and get it going again.