Federal Pacific Electric Stab-Lok Service Panels & Breakers:
Federal Pacific Electric “Stab-Lok” service panels and breakers are a latent hazard and FPE circuit breakers can fail to trip in response to over-current, leading to electrical fires. The breakers may also fail to shut off internally even if the toggle is switched to “off.” Some double-pole (240-Volt) FPE circuit breakers and single-pole FPE Stab-Lok circuit breakers simply do not work safely.
There are other FPE panel-defects independent of the breaker problems, panel, and panel-bus fires and arcing failures in some equipment. The failure rates for these circuit breakers were and still are significant. In some cases, failure to trip occurs 60% of the time – a serious fire and electrical shock hazard.
Zinsco Panels & Breakers:
Zinsco and Zinsco-Sylvania panels and circuit breakers do not offer the level of over-current and fire protection provided by most other electrical panels and circuit breakers. Homes with this equipment may be at greater risk of fire or another electrical hazard.
Limited test result reported by J. Aronstein indicate that the central Zinsco electrical panel and circuit breaker failure problem appears to be burn-ups at the clip-to-bus connection. A circuit breaker whose bus connection burns can lead to overheating damage to the circuit breaker itself, rendering it non-functional.