I have seen that big resistor a little darkened by heat, but never enough to catch fire like that. I too would have expected a stalled, overheating motor to be the issue.
Don't let trumpton see this thread or metal fans will be in the next set of regs.
I have seen that big resistor a little darkened by heat, but never enough to catch fire like that. I too would have expected a stalled, overheating motor to be the issue.
I thought the product standard called for a thermal fuse to be buried in the windings. I have certainly replaced fans which have failed because this has operated.
A colleage told me about a chap he knew (all the usual cavats about chinesse wispers, and it may just be a story, etc, apply....) who did a PIR/EICR on a reasonably newish, but at that time unoccupid office building. He has been issued a set of keys and was just about to lock up after finishing (and was going to issue a satisfactory verdict), but he decided he needed a pee, as he was finishing up in the bogs he thought he smelt smoke, lifted a ceiling tile and found an inline fan on fire, he'd put some fan isolators on that had previously been off and this fan obviously had some kind of fault. Luckily for him, a) he had stopped for that pee and b) the extinguishers had been left in the building and not taken by the tenannt. Otherwise he may have posted off the satisfactory and the building being a smoking mess!...