SSR information

  • Found some interesting information on YouTube about SSR's. You can see when he disassemble a 40 Amps SSR and find that it is actually rated as 16 Amps.

    Youtube movie

    Found another one about a cheap SSR teared apart.
    YouTube movie 2

  • Cheap stuff is frequently junk. Surprise surprise!

  • So they seem to be running about:

    25/6 = 4.2

    40/16 = 2.5

    "Over rated".

    The data sheets DO NOT show this as legitimate... At the same time, the "absolute max current" on the datasheets is at 100C while bonded to 2oz copper on a PCB. The "Fotek" and similar are bonding to a quite large and thick piece of metal.

    Good data points all.

    It would be interesting to run a Fotek or similar at its labeled current for a couple of hours in a 22C room, and see what the back plate temperature is.

  • The only one of these I have on a heated bed at the moment is labeled "40A", which probably means it is 16.

    The bed is about 1400W, on 110/120V (US standard). So about 12A. Seems OK. Also, it has been in operative use for some months, and I've applied the highly scientific "put your hand on the case" temperature reading. It is never even warm, in an average room (about 21 to 22C).

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