Comment on Repair or not, electrical heater switching circuit
litchralee@sh.itjust.works 3 days ago
My experience is mostly with repairing lower voltage devices (eg 12v to 54v PoE). In your case, a phase to phase short has made quite the mark on that PCB, and being a much higher energy event than low-voltage DC, its possible that some delamination has occurred, with downstream effects on expected trace resistance, capacitance, and leakage/creepage.
Were this a low-voltage board, I personally wouldn’t be worried about those downstream effects. But for AC line voltage, I’d rather buy myself the peace of mind. Do keep parts from the dead board that are salvageable, but IMO, a thermal event on the AC side of a 400v board would disqualify it from continued service.
BigDanishGuy@sh.itjust.works 3 days ago
I don’t know what stopped it. I wrote the occupant, but it was really just me. Neither RCD or fuses were blown. There’s a fuse (bimetal in a plastic box positioned above the heating element inside the heater) in series with the heating element, but that’s 400mm from the short, and its probably only there to prevent overheating and setting clothing coverie the heater on fire.
A new heater is 200€, because it has to be 400V as there’s no neutral wire available. That’s why I’d even entertain the idea of repairing the board.
litchralee@sh.itjust.works 3 days ago
Would it be possible to rewire the supply wires so that it provides 230v line and neutral? That should make it easier (and hopefully cheaper) to select a heater, although the heater would not be as powerful.
BigDanishGuy@sh.itjust.works 3 days ago
I could rewire the heating circuit, but doing so without the backing of an authorized electrician would be illegal. I’m already on thin ice just installing the heater by self.
But the thought has crossed my mind, as I have noticed there being an order of magnitude more 230V heaters on the market than 400V. On top of having to rewire everything, I’d have to put in a new 3 phased breaker, otherwise I’d be pulling way too much current… Let’s just say that this 1200W heater isn’t the only one we have in operation in my house.
litchralee@sh.itjust.works 3 days ago
I see. Given those constraints then, I don’t see any option besides a new heater. Ideally, the new heater would be built with less circuitry, so there would be fewer things to break.
Looking at the Adax Clea product description, it seems overly complicated for a radiator, IMO. I’m not sure I’d want triac switching for something like a heating appliance. Resistive heating doesn’t strictly require silicon switches, when a relay should work. But I suspect an equally-svelt radiator that’s also simple may be hard to find