At least in Austria and Germany plenty of rewirable plugs failed back in the old days because manufacturers dipped the ends of the stranded wires in solder before clamping them under a terminal screw. The solder moves under the pressure of the screw and the termination then overheats. I'd say that was clearly the issue in roughly 90% of the failed plugs I've seen. Unless I've forgotten a few I've only ever come across one failed moulded plug and that was on an early-2000s dishwasher and the plug failed in 2016, taking the socket with it. The socket was only three years old, decent-quality and tested after installation so I'd rule that out.
Don't forget that there's a very large grey area between a 'comfortable maximum' (IEC 60320 rates that at a pin temperature of 70°C, except for the higher-temperature variants which may reach 120°C or 155°C when further heated by the appliance) and actual meltdown; I've previously run heaters (up to and including 2.4kW @ 240V) through (deliberately long and silly-looking) chains of IEC 60320 C13/C14 cords, to prove the point that it would still work (which it does) . They are mixed 0.75mm^2 and 1.0mm^2, and none of the flexes themselves get warmer than I'm comfortable with. So far, I've only had one pin actually melt the plastic (which I later diagnosed, by autopsy, as a really bad crimp connection that didn't hold onto the wire at all!), but many pins still get too hot to touch (these are mostly "modern" versions, usually from Chinese/Taiwanese manufacturers).
(But then, surely a 10A-rated connector sustaining a heater drawing 10A is just the basic call of duty .)
I did have one other defective C13 socket, on a molded cordset made by CMA (back in the 1980s, at a guess). This, however, was a completely different fault: There was a bit of stray PVC in the active/line slot. This cordset ran cool while the connectors were properly seated, but the errant bit of PVC carbonized and created a nasty resistive path (releasing clouds of smoke) when I unseated the C13 end under load. And this one was a bit tragic, really, as the contacts themselves looked much more robust than in newer versions. (I salvaged it by cutting off the C13 end and converting it into a short extension cord.)
Apart from such occasional defects, though, the earlier molded cordsets were fantastic (if observed trends continue, they could well provide centuries of reliable service)... Between the "new" Chinese/Taiwanese versions and decent rewireable connectors, though, I think I'll stick with rewireable (for heavier loads, at least).
By failed I mean "got hot enough to smoulder and turn a crispy dark brown" or even "hot enough to burn holes around the pins". If you look at a white plug and see a brown circle around one pin you know what's going on. I've hardly ever seen that with stranded wires straight under screws (technically illegal according to German VDE regs) so I'm fairly certain the solder was the issue. It's similar to the troubles with household-size Al wiring in screw terminals.
Rewirable plugs and trailing sockets have pretty much become a DIY item here, everything sold in a store will have a moulded plug on it. Of course electricians do use them for repairs and site-made extension leads too but in Germany the general assumption seems to be that repairs are supposed to be made with OEM parts (i.e. if a moulded plug fails or the flex is damaged near the plug you need to replace it with an entire new flex with moulded plug supplied as a manufacturer spare) and site-made extension leads require all sorts of compliance paperwork and testing so it's safest not to touch anything. At least I see that attitude becoming more and more common in web forums.
Just last year, I bought a Kambrook KFH660 (and reviewed it here) -- which as basic as it is, is still a great heater for the price. It's just passed its warranty length, with no functional problems.
However, the pins on its plug already get rather hot when operating at full power. (Of course, they're nowadays stuck with buying the usual China/Taiwan cordsets; because no Australian company makes them anymore, and using the IEC 60320 C18 inlet -- as logical, and convenient, as that would be -- would expose them to an inevitable frivolous lawsuit, the minute someone plugged one in with a counterfeit cord. )
(I kind of wish they'd also make a 600W version, with a C8 inlet; that would be really cute, and still powerful enough for many small rooms. Too bad that the general public has such an unhealthy fetish for "MOAR POWAH", and oversized homes...)
I'll shortly be buying a few Clipsal 439S, to replace the plugs (on it, and my other full-size heaters)…
(And let me tell you: I've surely taken the environmental high ground, compared to my nearest neighbor who still uses an open fire. Seriously; if those aren't obsolete, then I don't know what technology is. )
I'm amazed at the details in your review of what sounds like a 'basic' electric, fan forced space heater. (KFH660 via the link)
It looks to me that you enjoy taking things apart and doing a thorough analysis. To satisfy my thoughts, how much time did you invest in doing the take apart & put back together?
I agree, John (HotLine1), it's one thing to take things to pieces and re-assemble them and I'm not trying to be nasty here, but this treatment of a simple heater, sounds pedantic, these things are mass-produced and you get what you pay for, because that is what consumers are willing to pay for, they are cheap and effect a means to an end. Personally I don't use electric heating at all, as it is too costly here in New Zealand, I prefer an Eco-Fire, log-burner, because that is what I have, sure it's a pain in the arse getting wood in from the wood-shed, but it heats the whole house.
Yes Mike, I’m still amazed at the details. I get spec books along with plans, and there is more details in Longrunners posts. I meant no disrespect either, just would like to know the man hours invested.
Re: Extension cords
#219648 09/20/1808:54 AM09/20/1808:54 AM
Hi im back been absent for a while as had a truly terrible year so far be glad when 2019 gets here cant be nearly ad bad as 2018. Anyhow back on topic Paul UK its interesting what you say about old UK plugs because a while ago a friend gave me a 2amp 3 way adapter I noticed its live pin appears to have half its diameter missing starting just after pin leaves the adapter body now I assumed it had had some sort of accident or something but now it looks like its a deliberate thing if im reading your earlier post correctly. Its made by clang is off white color rated 2 amps 250 volts