When it comes to home safety, electrical panels are the first things that need to be inspected. With regular maintenance, the electrical panels we have today can be expected to work properly for at least a few decades.
However, just because an electrical panel seems to work properly today doesn’t mean it will protect you from an electrical fault or overcurrent tomorrow.
Some older electrical panel brands have been known to fail consistently at higher rates than what can be considered safe.
One of these electrical panels is known as Zinsco.
Zinsco breaker panels are dangerous and no longer considered safe to use. Zinsco breaker panels are known to not trip in the presence of overcurrent or short circuits. Due to the type of aluminum used, Zinsco breakers can melt and fuse to the bus bar. If this happens, the breakers will not be able to trip and can cause electrical fires.
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People don’t really talk about Zinsco’s electrical panels as much as they do for some other types of panels. I feel like every homeowner needs to be aware of what a Zinsco panel is, its problems, and what that would mean for them as a future homeowner.
Let’s begin with a brief story of how Zinsco came to be in the first place and what happened that led them to manufacture their panels and breakers the way they did.
What Is a Zinsco Electrical Panel?
In 1943 Zinsco was established.
The electrical panels sold by Zinsco were prevalent between the 1960s and 1970s. They were installed in many buildings and home properties in North America.
Today they can still be found in some of the older houses.
A few years later, in 1963, Zinsco started manufacturing a new kind of breaker. Their new breaker was the only product that was a 240 volts twin circuit breaker that could make contact on both bus bars. As a result, this made their breakers extremely popular.
Later in 1973, Zinsco was sold to GTE Sylvania. The production of these panels continued until the late 1970s until 1981, when Zinsco panels production stopped. However, the electrical panels that were already produced were still installed in buildings for a few more years.
Today Zinsco panels are deemed outdated and a significant electrical hazard.
How Electrical Panels Provide Safety?
Electrical panels are among the most important, if not the most important, safety devices in any building. Electrical panels receive and then distribute the electricity throughout the circuits in our home through electrical breakers.
Electrical breakers serve as a gatekeeper protecting our electrical circuits from power surges and short circuits. If they detect a potentially hazardous situation, they will immediately shut down the electrical supply, thus preventing any electrical shocks or fires from happening.
If the electrical panel or its breakers don’t work properly or don’t trip, this can lead to serious electrical hazards, electrical shocks, fires, etc.
In the case of an overcurrent happening, if the breakers don’t trip, there will be extremely high amounts of electricity allowed to go through the wiring in the building. The danger comes from the high temperature that is generated by electricity. Eventually, this will melt the wiring, breakers, and the electrical panel and start an electrical fire.
2. Short Circuit
There are different kinds of short circuits. If a short circuit happens, this means that the electricity travels through a different path not intended for it.
This is extremely dangerous as it can lead to electrical shocks and even electrocution.
Are Zinsco Electrical Panels Dangerous?
It will not necessarily be easy to spot if there is a problem with your Zinsco panel. They may appear to work correctly for many years without failing. Even if you try and remove the cover, this is not going to help.
Zinsco electrical panels are considered dangerous by electricians and industry experts. Zinsco breakers melt and fuse to the aluminum bus bar causing failure in about 25% of the panels inspected.
1. What Makes Zinsco Electrical Panels Dangerous?
In the beginning, Zinsco panels were manufactured with copper bus bars. The clips on their breakers were copper too. During this period of time, only three types of material were allowed to be used as an electrical conductor: gold, silver, and copper. Copper was the preferred material.
During WWII and the Korean war and up to the 1960s, the U.S. was going through some major copper shortages.
The severe copper shortage led to some NEC (National Electric Code) changes, which allowed aluminum to be used in the manufacturing process of electrical panels and breakers.
Some manufacturers continued to use copper, but others had to use aluminum, and Zinsco was one of them.
Although aluminum is being used today in some electrical panels, the one used back then was of a different alloy with slightly different properties.
The aluminum used for the Zinsco panels was not of the best quality. It was prone to oxidation, and oxidized aluminum has an insulating property, not conducting one. The results were numerous burn-outs and electrical fires.
Because of that, there are several significant reasons why Zinsco panels are not safe:
- The circuit breakers can melt and, as a result, fuse to the electrical panel’s main bus bar. In doing so, this prevents the breaker from ever being able to trip. The circuit will stay closed, and electricity will pass regardless of how bad the power surge or the short circuit is. Eventually, the panel, breakers, and wiring will overheat and catch fire.
- The poor quality of the aluminum used.
- The breakers might not connect to the bus bar in a proper way. If the breakers are connected loosely to the bus bars, this may cause arcing. Arcing produces tremendous heat that may set the whole panel on fire.
- The bus bars tend to corrode easily.
- Even though the breakers may appear to be off, they may not have cut out the power and still allow for electrical current to pass.
- It is believed that Zinsco panels might not pass today’s UL requirements. If they cannot pass the safety requirements, they will not be sold on the market.
- In some cases, they could be set up as a two-wire system without a ground.
2. What Are the Signs of a Bad Electrical Breaker or Panel?
Several small signs can point towards a problematic breaker or panel. Keeping an eye for these might prove of great value.
If you spot anything that may raise your concerns, always make sure to consult a certified electrician to have the panels and breakers thoroughly inspected.
- If you notice any burning smell coming from the breaker or the panel.
- If there are any burned areas of the panel or breaker, damaged wiring, or other wear and tear types.
- No buzzing noises coming from the panel.
- Any flickering lights in the building.
I want to add that not always a problem will be visible to the naked eye. And just because we might not see any signs of burned areas doesn’t necessarily mean the breakers are working fine.
This is especially true with Zinsco and FPE electrical breakers, where even a more in-depth inspection might not be able to uncover a soon to fail breaker.
3. How to Test If the Electrical Panel and Breakers Work?
One of the frequent questions I receive regarding any of the potentially dangerous breakers is whether we can test them to see if they work.
That sounds good on paper; however, it is more difficult than expected in reality.
Both the FPE breakers and Zinsco breakers share a vary bad characteristic. Even if tested, we may never know if they will work properly or not in the future.
Visually inspecting the breakers, manually switching them off and on, or seeing if they are connected securely to the bus bars might not give us any clues if they are working correctly or if they will work properly.
In fact, manually tripping them and resetting them could even be a reason for them to fail in the future.
What Is the Official Stance from the Government Agencies?
If Zinsco electrical panels are so widely considered a fire hazard, there should be some official data on this.
Well, not necessarily. Zinsco panels fall in a very tricky category.
Just like the infamous Federal Pacific panels, they too are officially considered okay. There is no official support or evidence from any government or regulatory agency that confirms their lack of adequate protection.
- So, on the one hand, we can consider them legal to be used.
- On the other hand, however, many home inspectors and electricians have reported the numerous times they are failing.
Like the FPE panels, Zinsco is considered unsafe and a serious fire hazard despite not being officially recognized as such by any government agencies.
There have never been any official recalls of the Zinsco panels either.
Every home inspector or certified electrician knows that when they find a Zinsco panel, they find themselves in a difficult situation. Since there is no official data, a homeowner may feel like an electrician who advises them on an electrical panel upgrade when no damage may be exaggerating the severity of the condition.
However, both home inspectors and electricians are responsible for what we do and our client’s safety. Being aware of the inherent fire risk Zinsco provides, there is no way that we would not recognize the risk for our clients.
Zinsco panel is always recognized as a serious hazard. Thus we are obliged to inform our clients of the possible future dangers.
How to Recognize a Zinsco Breaker Panel?
Since Zinsco panels are no longer manufactured, you will not find them in newer buildings. However, they can still be found in older homes and properties built before 1990.
- There usually is going to be a label with the Zinsco logo on the panel.
- Zinsco panels were frequently labeled with the name Magnatrip.
- Other labels that may indicate you have a Zinsco panel or Zinsco rebranded panel include Sylvania, Sylvana-Zinsco, and GTE-Sylvania-Zinsco.
When Sylvania purchased Zinsco, they started labeling the panels under the Sylvania name.
However, these don’t seem to be any different than the original Zinsco panels. In fact, they may be the same design with a different sticker on top.
So they should be treated as basically the same electrical panel with the same weaknesses.
What Happens During a Home Inspection of a Zinsco Panel?
Although many areas are going to be covered, some things are not included in a home inspection. So it is essential to know what is and what isn’t included in a home inspection.
1. What Does a Home Inspection Cover?
The home inspector’s responsibility is to evaluate any accessible and visible parts of a home and identify any points of concern.
Future health and safety of the property and the owners are our primary focus as home inspectors.
After the home inspection is finished, the homeowner is presented with a home inspection report. The report will find detailed information about the status and condition of the different elements of the property, including any potential hazards and recommendations.
During any home inspection, the electrical panels are the first things to be inspected and assessed.
However, not everything can be thoroughly evaluated, and in some cases, they need to be check by an electrician. For example, a home inspector may remove the cover of the panel but will not remove breakers to inspect the bus bar’s connection. This is beyond the home inspector Standards of Practice.
Since home inspectors are required to inspect only visible and readily accessible parts of the building, inspectors cannot remove the panel breakers.
As a Certified Master Inspector in the field, I make decisions daily based on the information in front of me. Some inspectors will open these panels, for one do not, and there are reasons for that:
- For safety, the main disconnect needs to be turned off to remove and inspect the panel safely. Many older homes do not have a main disconnect installed, preventing cutting power off to the breaker box for internal inspection.
- Most obsolete electrical panels can’t be repaired. You can’t run down to the local hardware store and purchase new parts to fix them. You’ll often see replacement parts sold on eBay or in salvage yards, but this should never be recommended.
- The only safe repair for an obsolete electrical panel is a full replacement of the entire electrical panel. If I see an electrical panel that is unsafe or obsolete, I document the panel is present and refer it for replacement by a licensed electrician.
2. Will a Zinsco Electrical Panel Pass Home Inspection?
Zinsco panels and breakers have proven to be less reliable than other similar products.
When they are evaluated during a home inspection, they are considered dangerous and a latent fire risk. Even though they may be working today, there is no guarantee that they will not fail tomorrow or a few weeks from now.
Zinsco panels are grandfathered into the electrical code, but that doesn’t mean they are safe to use. They were legal during the period they were installed, and they are still regarded as legal now by building code standards. In addition to that, there is no specific information and stance from the Consumer Product Safety Commission (or CPSC). And there have never been any recalls initiated on the Zinsco panels.
So from a legal standpoint, they are considered okay.
However, no home inspector will be able to ignore the numerous cases of Zinsco’s breakers going bad. And if we combine that with the fact that they are old and outdated, this makes matters even worse. Even the “newer” ones are going to be at least 40 years old.
Of course, even the newer panels and breakers we have today can fail. Given that these panels are obsolete and have known problems, home inspectors are in a tough spot.
Despite the lack of any authoritative standpoint, a Zinsco panel should always be classified as a safety concern and a latent fire hazard upon a home inspection. As such, your home inspector will advise on hiring a certified specialist to check the condition of the panel, wiring, and breakers.
3. The Limitations of a Home Inspection
A home inspector can not easily inspect the problems Zinsco panels and breakers have as we cannot remove or tinker with the panel or the breakers. This needs to be done by a licensed electrician.
Based on the history of Zinsco, home inspectors can only recommend that an electrician evaluate the panel and breakers. If the electrician finds no defects, we cannot enforce a Zinsco panel to be changed.
Home buyers are recommended to do some research on their own. That way, they can make a well-educated decision on what to do. Usually, it is up to the client to decide what would be best for them.
Purchasing a Home with a Zinsco Panel
There is a lot of conflicting information on the Zinsco topic.
For some future homeowners, a property with an already installed Zinsco might raise some concerns. It can even be a deal-breaker in some cases.
1. Negotiating a Home Inspection Contingency
As a home inspector, I feel like it is essential to stress always having a home inspection contingency when buying a new home. To be in full effect, it needs to be signed by both the seller and the buyer, as this will make both parties legally bound.
A home contingency is a specific set of requirements that need to be met for the contract to move further. There can be many different types of contingencies. In the case of a home inspection contingency, the property needs to pass the home inspection.
If there are points of concern or serious hazards discovered by the home inspector, the buyer will be protected by the home inspection contingency. They will have a few options:
- The buyer can negotiate repairs or a reduction in the price.
- Back off the deal with his earnest money.
- Even if the property you are interested in buying doesn’t have a Zinsco panel, there might be other serious hazards or details that the seller never mentioned. A home inspection contingency will have you protected in such cases.
2. What Is the Cost of Replacing a Zinsco Electrical Panel?
If you are considering purchasing an old house with an obsolete electrical panel comes with risks and uncertainty.
Replacing a faulty electrical panel can cost big money, in some cases, several thousand dollars.
The average cost of replacing a Zinsco electrical panel is between $1,500 to $2,000. Depending on the panel’s amperage (150A or 200A panels will cost more), any extra labor or any materials used for repairs and reforming. The costs may go up to $2,500 and more in some cases.
Some other factors that will affect the price for replacing a Zinsco panel are:
- Your area and municipality.
- The total amount of labor.
- Any demolition work.
- The condition of the wiring.
- The presence of any obsolete wiring.
- The size of the electrical panel.
Depending on the condition of all of these and other factors, even newer wiring might need to be installed.
3. How Zinsco Panels Affect Home Insurance?
Insurance companies and even lenders (if you are looking for a mortgage) know the inherent risk of insuring properties with older and outdated electrical panels.
If you have a property with a Zinsco panel installed, this might lead to your insurance coverage being canceled. Or you might receive a grace period during which you need to change your whole panel.
Insurance companies have become increasingly cautious when having to sign insurance for older properties with FPE or Zinsco panels installed. They have been receiving more claims related to such homes, so they are listed as a possible liability.
Many, if not all, insurance companies can even refuse to insure a property with a Zinsco panel due to their documented and proven fire hazard.
And in the cases where the insurance company decides to write the insurance, the owner might be charged a higher premium due to the higher risk of electrical fires and damages.
What to Do If You Have a Zinsco Panel?
First and foremost, do not try to remove the Zinsco electrical breakers by yourself as there is a risk of electrical shock due to their unsafety. Have a licensed electrician inspect the electrical panel and its breakers.
One of the most concerning decisions every homeowner has to take when faced with a Zinsco panel is the right thing to do.
Is it necessary to completely replace the Zinsco panel and the breakers? Or we can replace the breakers. After all, there are some replacement Zinsco breakers and retrofitted models that are being sold.
1. Do You Have to Replace a Zinsco Panel?
If you have a Zinsco panel, the first option is to replace the whole electrical panel, including the breakers.
This is the most costly option. However, the most frequently recommended and the best course of action safety-wise.
Replacing the Zinsco panel and breakers with a newer product from a reputable manufacturer is the best way to make sure your home and family are safe.
As we have just discussed, replacing an electrical panel can frequently come as an unexpected expense that might be a few thousand dollars in total. And that should always be considered during the purchase of a home.
2. Do You Have to Replace the Zinsco Breakers?
Another option some homeowners might entertain is just replacing the Zinsco breakers. However, replacing the breakers is not recommended as this will not remove the inherent danger.
Even “newer” units can malfunction, and there is no known proof that they will be more reliable and safe than the older models.
Not just that, but there are inherent problems in the bus bars of the panel and the materials used for their manufacturing. Even if you replace the breakers, the risk that stems from the panel itself will still be present.
3. Can You Choose Not to Change the Panel and the Breakers?
As home inspectors, we are responsible for pointing out any potential future hazards that may occur. We cannot ignore the possible dangers of having a Zinsco panel.
Even though it is recommended for any Zinsco panel to be changed, nobody can enforce that change.
So if it appears to work normally, we will note that in the inspection report. But I will still recommend having the electrical panel inspected by a certified electrician for further advice.
Electricians, too, usually recommend the service panel to be changed due to the inherent risks. However, the final decision is up to the homeowner.
Are There Other Electrical Panels Considered Unsafe?
There are other types of electrical panels considered unsafe and hazardous or just plain outdated and should always be upgraded to a better panel.
Just like Zinsco panels, they have some critical issues that can put our home and family in danger.
Federal Pacific panels are the most commonly found electrical panel in older homes that are also considered extremely unsafe. You can read our article Are Federal Pacific Electric Breaker Panels Safe? Dangers & Cost to Replace here.
FPE panels have shown poor reliability and extremely high rates of failing to trip in the presence of electrical overcurrent. As a result, a high risk of starting electrical fires and electrocution.
How Much Does it Cost to Replace a Zinsco Electrical Breaker Panel?
Replacing a Zinsco panel will vary depending on its size, amperage, and location.
So, how much does it cost to replace a Zinsco breaker panel? Replacement of a Zinsco breaker panel costs about $1500-$2000. However, the replacement of the panel often is accompanied by other repairs to meet current electrical codes.
- Relocation to an area of the house that meets clearance requirements for local electrical codes.
- Installation of arc fault and ground fault breakers.
- Wiring upgrades for some or all branch circuits.
- Installation of the main service disconnect.
- Upgrading the 3 phase main service entrance wire from the meter base to the panel to 4 phase wiring.
There are additional costs to consider when replacing a Zinsco electrical breaker panel. To meet current local electrical building codes in your area, most Zinsco breaker panel replacements will require:
- Moving the electrical panel to an area of the house that meets clearance requirements for local electrical codes.
- Installation of arc fault and ground fault breakers, which are more expensive.
- Electrical wiring upgrades for some or all of the house’s electrical circuits. Complete re-wiring of a home can cost $10,000 or more.
- Installation of the main service disconnect. Many old houses do not have a main disconnect.
- Upgrading the 3 phase main service entrance wire from the meter base to the panel to 4 phase wiring.
- Extending the service mast and weather head above the roofline or moving the service feed underground.
Unfortunately, the high cost for changing a Zinsco panel often discourages homeowners from replacing the panel, but so can be the cost for not doing it.
Many fly-by-night electricians or DIY homeowners installed replacement installations with short cuts to save money that result in more electrical safety problems than they started with.
If you have a Zinsco panel and want to replace it, you need to consult with a licensed electrician to get a quote.
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