Zinsco Electric Panels

There is no question that electrical issues, especially those related to panels themselves, rank high on the list of home inspection findings. One problematic panel in particular, Zinsco, was widely installed as early as the 1950’s and through to the 1970’s. They were later manufactured for a time by Sylvania and are still commonly found in homes built even in the early 1980’s.

While many of these panels could be described as cheaply constructed, cramped and difficult to work on, the biggest issue relates to the breakers themselves.

While most all breakers are thermal/magnetic, Zinsco/Sylvania breakers are thermal only. This means they must get hot internally before they trip and therefore can be slow to react to overloads and short circuits. In some cases, the breaker may fail to trip altogether, causing wires, outlets and/or the breaker itself to overheat. For that reason, many experts consider these panels to be a latent fire hazard. While there was never any recall or class action lawsuit involving these panels, the wealth of anecdotal information from electricians clearly speaks to the issue.

One local electrician, Jim Simmons, has had extensive experience with these panels and has been active in educating consumers and home inspectors about the issues. He reports that 10% to 15% of the panels they inspect have serious damage. These damages include burned connections, arcing which has burned holes in the metal buss bars the breakers connect to and breakers which are so heat damaged they literally crumble apart when removed. Many of the older panels also lack a main shut off to kill all the power in the panel, thus creating serious shock hazards for anyone working on the panel.

Another concern indirectly related to the issue of breaker failure is the mentality of many who believe that because it has never been a problem, it never will be. The inherent flaw in that thinking makes two fatal assumptions: The first is that conditions never change and the second is that because something is not readily visible it is not an issue. In reality, overheated wiring or connections in light switches, outlets and junction boxes usually go undetected until something catastrophic happens. And overheating issues within the panel generally can only be seen if the breakers are removed, a task suited for a qualified electrician only. For the home inspector the facts are clear and it should be a routine recommendation that these panels be professionally evaluated for safety.

Larry Stamp AD, BS, RREI

Larry owns and operates Cameo Home Inspection Services and is a home inspection instructor at Kaplan Technical College. He can be reached at 360- 459-1632.