Federal Pacific and Zinsco panels: should you replace yours?

If you live in a home built between the 1950s and the 1980s, there is a chance your electrical panel was made by Federal Pacific Electric (FPE) or Zinsco. Both brands were installed in millions of homes. Both are now known for breakers that may not shut off power when they should.

How to tell if you have one

• Federal Pacific: look for "Federal Pacific Electric" or "FPE" on the panel door or label, and breakers marked "Stab-Lok". The breakers are usually thin with red or black handles.
• Zinsco: look for "Zinsco" or "GTE-Sylvania" on the label. Zinsco breakers often have colorful handles in blue, red, green, or brown.
• If the label is missing or painted over, a home inspector or electrician can identify the panel by its breakers.

Note that today's "Federal Pacific" name is used by an unrelated company that makes commercial equipment. The concern is with the residential Federal Pacific Stab-Lok panels from the original company.

What's wrong with these panels?

A breaker's main job is to trip when a circuit is overloaded or shorted. Independent testing of Federal Pacific Stab-Lok breakers found that a significant share failed to trip under those conditions. A breaker that stays on lets the wire overheat, which can start a fire. Some Stab-Lok breakers also fit loosely in the panel, which can cause arcing where the breaker connects.

Zinsco panels have a different problem. Their breakers attach to aluminum bus bars, and over time the connection can overheat, arc, and even melt the breaker onto the bus bar. A breaker fused to the bus bar cannot trip, and it can't be removed or replaced.

Warning signs to watch for

• Breakers that feel warm or hot, or a panel cover that's warm to the touch
• Burn marks, melted plastic, or a burning smell near the panel
• Breakers that won't stay on, or that don't trip when a circuit is overloaded
• Flickering or dimming lights across the house
• Buzzing or crackling from the panel

If you notice any of these, call an electrician soon. Don't open the panel cover yourself.

Insurance and selling your home

Many insurance companies ask about the electrical panel, and some will not write or renew a policy on a home with a Federal Pacific or Zinsco panel. Home inspectors routinely flag them, so a buyer may ask for a replacement or a credit before closing. Replacing the panel before you sell can remove a common obstacle.

Can you just replace the breakers?

Replacement breakers are sold online for both brands, but swapping breakers doesn't fix the underlying problems with the panel design, bus bars, or aging connections. Most electricians recommend replacing the whole panel.

What replacing a panel involves

A panel replacement usually takes a day. The electrician coordinates the power shutoff with the utility, removes the old panel, installs a new panel and breakers, reconnects each circuit, labels the directory, and arranges the city inspection. It's also a good time to add capacity if you're planning an EV charger, a generator, or a remodel, and to add whole-house surge protection, which current code requires when a home's service is replaced.

Cost depends on the size of the panel, whether your service needs to be upgraded, and the condition of the wiring. Koryente will look at your panel and give you a written price. You can also get a rough idea with our electrical cost estimator or learn more about panel upgrades. The labeled panel pictured above is from Koryente's work at Monarch Crossing Office Park in Fort Worth.