This article explains what to do and how to diagnose a shorted DC power Supply
Attached is the PDF Version with Pictures to aid in diagnosing
Case Number SC57337
Issue: DC power supply shorted
Description of problem:
Dc power supply shorted out / DC OK light not on
Things to check:
- Any incidents that happened shortly before problem first began?
- Check for 24 volts dc on DC Power Supply between + and – terminals
- If no power remove wires from all “+” terminalS and recheck for 24vdc if you have power after removing wires go to step 4 if not go to step 3
- Check power going into power supply should have 120 volts AC
- If you have power customer has a bad power supply
- If you don’t have power trace circuit back to confirm why. Double check the circuit breakers in the cabinet
- There is a short somewhere in the 24 volt circuit, at this point it is usually best that an electrician be called in: best practice for finding a short in the 24vdc circuit is by removing 1 wire at a time from the input terminals 24vdc+ (middle terminals) and watching if the DC OK light comes back on, if it does than you found the short and that circuit needs to be traced back to where it goes to find the issue.