The National Electrical Code currently bans the Federal Pacific Panel Breaker model. This means it's illegal to use this type of system in new homes or businesses, but you could still have one in your home that was installed years ago.
These systems also lack a ground wire which can be very dangerous if there are other electrical issues on your property. Not only that, but they're not capable of handling surges in power and will end up overheating after being used about 15 times. The fuses inside these panels blow out quickly and put you at risk for fires or shock when using them regularly because they don't meet current safety standards.