WiremanWireman · Problem panel brands: what to look for: troubleshooting for electricians · 2023 NEC ·
Problem panel brands: what to look for
Federal Pacific Stab-Lok, Zinsco and other old panels: warning signs, what to inspect, and when to recommend replacement.
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How it works
Some panel lines have long, widely reported track records of trouble. Federal Pacific Electric (FPE) Stab-Lok breakers have been reported in independent testing and lawsuits to fail to trip on overloads, and to fit loosely on the bus. Zinsco and Sylvania-Zinsco panels are known for breakers that overheat at the aluminum bus and can fuse to it, so they can’t trip or be turned off. Not every one of these panels has failed, but a breaker that doesn’t trip gives no warning until something overheats.
Every question and answer in this guide. Tap “Step by step” to walk through it.
- What brand is on the panel label?
- Federal Pacific (FPE) or Stab-LokDo you find any of these warning signs?
- Yes, one or moreAn old or problem panel with signs of failure
- No visible problemsA Federal Pacific Stab-Lok panel
- Zinsco or Sylvania-ZinscoDo you find any of these warning signs?
- Yes, one or moreAn old or problem panel with signs of failure
- No visible problemsA Zinsco or Sylvania-Zinsco panel
- Another brand no longer madeCan you still get breakers listed or classified for it, and is it in good shape?
- Yes to bothTest: Inspect the panel with the cover off
- Heat, corrosion or burn marksAn old or problem panel with signs of failure
- Double taps or shared neutralsWiring mistakes in the panel
- Clean, tight and coolThe panel is in good condition
- No parts available, or it shows damageAn obsolete panel without good repair options
- Yes to bothTest: Inspect the panel with the cover off
- A current major brandAre all the breakers the panel’s brand, or listed or classified for it?
- YesTest: Inspect the panel with the cover off
- Heat, corrosion or burn marksAn old or problem panel with signs of failure
- Double taps or shared neutralsWiring mistakes in the panel
- Clean, tight and coolThe panel is in good condition
- Some are another brandBreakers not listed for the panel
- YesTest: Inspect the panel with the cover off
- Federal Pacific (FPE) or Stab-LokDo you find any of these warning signs?