Author Topic: When a MOV decides it is tired.  (Read 1547 times)

SeanB

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When a MOV decides it is tired.
« on: June 16, 2016, 08:29:55 AM »
So, came home to no power, and found the RCD had tripped. Reset and it still trips, so do a little isolation and come to the conclusion this power filter cum isolation transformer cum audiophool multiplug has an issue. While this may be an audiophool unit I did not actually pay anything for it, I just took it, removed the one failed isolation transformer in it ( cooked by being used to power a 200VA load while being rated for 50VA) and simply use it as a convenient PDU to feed the UPS input and also as an easy way to plug phone chargers in with minimal risk of shock.

So, disconnect and this morning take it apart to see what went pear shaped. No major smoke smell, so the mains filter itself has not gone up in flames, which is good, otherwise I would have to find a replacement to shoehorn in there. But the MOV (250V) is not looking too healthy any more.

Look closer, and it has definitely decided it is tired, blowing the one leg off, and with a little smoke damage on the surface and cracks along the side.

So, replace with another, funny enough, used in a HP laser in the middle of the machine as a static limiter in the paper path, but it will work here fine. Added a little PTFE sleeving to the leads and put the lot back together and it was done.