SSR Failure

[phxmark]

I had an SSR fail on me tonight.  It was hooked up to Aux1.  It somehow shorted the outputs (48 volts) internally to the negative terminal of of the SSR sending the full 48 volts to the negative terminal of Aux1.  Aux1 still works, but the ground trace on the back of the board that goes to the jumpers is burnt.

I have a fuse on the positive terminal but not on the negative terminal.  Aux1 still works, but I now I have to connect the negative of a new SSR to the common negative.

Anyone else ever have an SSR fail in this manner?  Now to find out how much it is going to cost to have it fixed.

[zoneblue]

What brand was it?

[boB]

It shorted the positive 48V line to the SSR's negative INPUT line ?  That is weird because they are
usually pretty well isolated.

boB

[phxmark]

Yup, 48v right to the ground.

I sent the old one back.  They want to examine it.  They are sending me an updated model that has better isolation.


My guess is the opto-isolator they used wasn't up to snuff.

I suggested to the tech that the put some pico fuses or other protection on the AUX outputs in the next Classic PCB version.

[zoneblue]

My guess it was a shitty ebay ssr...

[CDN-VT]

solid state relay ? is SSR
VT ?

[Halfcrazy]

Looking at this picture. I assume it is the SSR between the battery and the grid tie inverter with the suicide cord?

Couple thoughts would be. Is there a heat sink on that SSR? and I wonder what the battery side capacitance of that inverter is and if the inrush charging them is exceeding the rating of the SSR. I know A lot of inverters will trip a 80 or 100 amp breaker from the inrush.

If I wanted to do this I would switch the AC from the grid tie inverter myself.

Ryan

[boB]

I suggested to the tech that the put some pico fuses or other protection on the AUX outputs in the next Classic PCB version.

There is a PTC (resettable fuse) on the positive side of the Aux1 and Aux2 outputs for when the Aux output
shorts to negative.   Adding one for the ground could be done as well but that one would have to be rated
for high voltage because the smaller PTCs are only rated for 16 volts or so.  The larger PTC rated for
250 volts are too big to put on the PCB and we don't see this problem often at all.  I have heard of that
trace braking twice I think out of many thousands of Classics.

We will certainly discuss this for the next go around or next version of CC though.

Was it a Crydom SSR ?  Yes,  SSR = Solid State Relay.

Thanks,
boB