ATS & Changeover Panel Diagnosis

Automatic transfer switch and changeover panel faults — why a switch refuses to transfer, how to separate a control decision from a mechanical failure, and the interlock rules that exist to stop utility and generator being connected together.

What this covers

• ▪Failure to transfer on mains loss — ATS Not Changing Over
• ▪Failure to return to utility — Generator Will Not Transfer Back to Mains
• ▪Sensing, thresholds and timer settings — ATS Not Changing Over, Generator Will Not Transfer Back to Mains
• ▪Contactor, motor operator and interlock faults — ATS Contactor, Motor Operator and Interlock Faults
• ▪Position indication and auxiliary contacts — ATS Position Indication and Auxiliary Contacts

Diagnosis guides

• ATS Not Changing Over — Automatic Transfer Switch Diagnosis

  Contactor-based and motorised automatic transfer switches, single- and three-phase, controlling utility and generator supplies

  8 diagnostic steps · advanced · qualified electrician

• Generator Will Not Transfer Back to Mains

  Contactor-based and motorised automatic transfer switches on utility and generator supplies, single- and three-phase

  7 diagnostic steps · intermediate · qualified electrician

• ATS Contactor, Motor Operator and Interlock Faults — When the Switch Itself Fails

  Contactor-based, motorised breaker and motor-operated changeover switches, single and three phase, with mechanical and electrical interlocking

  8 diagnostic steps · advanced · qualified electrician

• ATS Position Indication and Auxiliary Contacts — When the Panel Lies About Itself

  Contactor-based, motorised breaker and motor-operated changeover switches with auxiliary contact position feedback to a controller or BMS

  8 diagnostic steps · intermediate · qualified electrician

Related categories

• Generator Repair & Troubleshooting
• Controller Diagnostics
• UPS Repair & Troubleshooting