Hi all, I wonder if anyone has come across a similar problem before?
My Siemens oven started tripping the mains RCD a few months back. I traced the leakage first to an element but then back to leakage across an HF3FD relay. The relay in question had a small bump on the side of it that was different to all others on the board. I ordered a replacement relay (from Germany via ebay), fitted it to the board and everything was hunky dory again.
Last week the oven failed again, this time quite spectacularly, with a heater element stuck on (I assume that was the cause I first noticed the smell of burning then wished I hadn't opened the door to check that everything was really really hot - oxygen plus really hot things => conflagration) anyway, no great harm done.
Taking the oven to pieces again today and I've got another (different) relay with a bump on the side and, sure enough, a large leakage through it.
Hmmm ... I put the first failure down to poor QC at the relay factory. Now I'm thinking, was my oven fitted with relays from a dodgy batch or is there something else wrong that's causing the relays to fail.
The oven had been behaving just fine. Over current through actuator coil or contacts I guess could damage a relay but both have failed across the isolation barrier. You'd need some big volts to do that normally and we haven't been hit by lightning ... that I've noticed.
As I say, if anyone has experience of repetitive relay failures I'd love to hear it.
My Siemens oven started tripping the mains RCD a few months back. I traced the leakage first to an element but then back to leakage across an HF3FD relay. The relay in question had a small bump on the side of it that was different to all others on the board. I ordered a replacement relay (from Germany via ebay), fitted it to the board and everything was hunky dory again.
Last week the oven failed again, this time quite spectacularly, with a heater element stuck on (I assume that was the cause I first noticed the smell of burning then wished I hadn't opened the door to check that everything was really really hot - oxygen plus really hot things => conflagration) anyway, no great harm done.
Taking the oven to pieces again today and I've got another (different) relay with a bump on the side and, sure enough, a large leakage through it.
Hmmm ... I put the first failure down to poor QC at the relay factory. Now I'm thinking, was my oven fitted with relays from a dodgy batch or is there something else wrong that's causing the relays to fail.
The oven had been behaving just fine. Over current through actuator coil or contacts I guess could damage a relay but both have failed across the isolation barrier. You'd need some big volts to do that normally and we haven't been hit by lightning ... that I've noticed.
As I say, if anyone has experience of repetitive relay failures I'd love to hear it.
via Relays failing on Siemens oven
by chrisf1874
No comments:
Post a Comment