Zinsco Electric Panels
Zinsco Electric Panels (some labeled Sylvania / Zinsco) have not been manufactured in many years. Zinsco began manufacturing electric panels in 1943 and was then sold to GTE-Sylvania in 1973. GTE / Sylvania manufactured the panels and components for a few more years. Currently the line is discontinued. Most of them are “split-panels” and do not have a single main service disconnect. This feature alone should warrant a panel and possible service upgrade.
At first look, the panels appear to be functioning properly; however the circuit breakers (which may have been overheating for a long time) may have bonded to the hot bus bar. The aluminum used in the breakers and the hot bus bar may have melted into the plastic components. Unfortunately this dangerous condition may not be visible during a normal home inspection because the damaged area is behind the circuit breaker.
Zinsco electrical equipment is considered obsolete and possibly dangerous. The design flaw, which may cause the connection between the breaker and the hot bus bar to become loose, could cause arcing and overheating. The breaker may become welded to the bus bar and unable to be removed. There are replacement parts available, however most electricians recommend the electric panel is replaced. Even though a breaker has tripped and appears to be off it may still be sending electricity because of bonded and melted internal parts. This is obviously a dangerous condition.
So what should a home inspector be looking for?
- Any electric panel or sub-panel labeled “Zinsco” or “Sylvania-Zinsco” or “GTE Sylvania” or “Kearney” should be closely examined for overheating / arcing damage
- Look specifically where the breaker is connected to the hot bus. This is where many of the failures have taken place.
- Never try to move a breaker, it may fall apart.
- Recommend to your client that these electric panels may experience problems and should be evaluated and upgraded as necessary by a licensed electrician.
- Use extreme caution because breakers that appear to be off, may in fact have current flowing through them. You should definitely inform your clients of this potentially dangerous condition.
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