Sanity Check Time

JimDawson

JimDawson

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I designed and built the following circuit. It consists of a power supply, two Solid State Relays, two DPDT PRD relays and two small linear actuators.

The PRD relays RR1 and RR2 act as the reversing contactor, the SSRs are the power switch.

The problem is that I seem to have a dead short. Double checked that the wiring is per the drawing.

The lower schematic is an alternate configuration, but the same function.

I don't see a shorted path, maybe you can see something

1674939802518.png

1674939877635.png
 
Don't see a short path in the schematic.
I'd suggest disconnecting one of the power rails, either one really. But say you disconnect the SSR from the 12V on both, and see if both chains still read as a short independently. I assume you're checking for short with an ohmmeter, rather than just powering it up. Also, I'd double check the resistance of the actuators for reference.
 
That screwdriver is blocking just enough of the wire harness that I can not follow the wires to see if there is a miss wire. Are you sure that the screw driver is not touching those terminals?
 
rabler said:
Don't see a short path in the schematic.
Click to expand...
Good, then I'm not crazy. :confused 3:
rabler said:
I'd suggest disconnecting one of the power rails, either one really. But say you disconnect the SSR from the 12V on both, and see if both chains still read as a short independently.
Click to expand...
Good Plan.
rabler said:
I assume you're checking for short with an ohmmeter, rather than just powering it up.
Click to expand...
Nope, I powered it up, energized the one of the SSRs and the power supply instantly crowbarred. I actually blew up one power supply, and just installed another yesterday. The first one I had forgotten to switch it to 220V input, it actually had a voltage select switch on it.
rabler said:
Also, I'd double check the resistance of the actuators for reference.
Click to expand...
Good idea.

I haven't done much troubleshooting yet. I'll be going down there tomorrow.
 
Flyinfool said:
That screwdriver is blocking just enough of the wire harness that I can not follow the wires to see if there is a miss wire. Are you sure that the screw driver is not touching those terminals?
Click to expand...
That picture was taken during assembly. The panel is now installed in the machine enclosure.
 
Could a motor (or the wiring to it) be shorted?
Try replacing the motors with light bulbs..... it won't give you direction, but it could give you an "all-clear" for the control wiring and logic.

Brian
 
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