Breakers or Fuses?

When you selling or buying a home does the fact the home contains a circuit breaker or fuse panel ever come up, do you think about it, and should you?

When in a home with a fuse panel, often times it may be stated that it will need to be replaced.  Is that an accurate statement?

Well, the insurance company may think so, but is that correct or are they overreacting?

 

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Well let's begin with a few important facts about fuses:

• a fuse will react more quickly than any breaker - hence fuses are still used today in all sensitive electronic circuit protection.
• a fuse can be sized smaller and more accurately than any breaker, hence the very small sizing available in electronic circuits - as low as 2/1000 of an amp are available.
• fuses stand up to vibrations more reliably and will not trip accidentally - hence why your automobile still uses fuses.
• regardless of age, fuses will maintain their accuracy and reliability.
• fuses are available in a wider variety of voltage and amperage increments.
• fuses will operate in a vast range of temperature, environmental, and atmospheric conditions. A fuse can be placed almost anywhere and they will provide the same degree of reliability.
• fuses are not impacted by moisture, dirt or other nasty environmental exposure.
• while not as critical for our house panel, fuses can be designed to act much faster.

Yes that is right.  Fuses are physically a carefully designed metallic strip, that when a specific quantity of electrons or current flow, it will heat - melt and open the circuit.  A breaker works in a mechanical nature, whereby the current flow creates a magnetic field, which when strong enough will trip the breaker. 

When we want to protect something and be absolutely certain of the results, there is no option other than a fuse.

 

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Having said that, why do many, including insurance companies think they are so bad?

Well, it is history.  While fuses will never fail, and breakers have been known to, a fuse can easily be bypassed by the occupant or over-sized.  Let's look at some of the risks of a fuse panel,

• oversizing of fuse - with a fuse that is a problem with frequent blowing - replacing with a larger size one - this can be a fire hazard as the conductor is now not properly sized for the current the fuse will allow to flow.
• bypassing completely - placing aluminum foil or a penny in the socket before screwing the fuse back in - essentially removing all protection completely.
• fuses are becoming more difficult to find - and you must have spares on hand - hopefully close to the panel.
• you need to have a flashlight on-hand near panel to replace fuses - in our house in the 1980's which had fuses, I installed a single light on a fuse all by itself at the panel.  As it was alone on fuse, no other overload would blow this fuse and put the light out.

What are some potential suggestions to make a panel safer?

• there two type of  inserts available:
  • the first is a plastic screw inserts - colored the same as the fuse - which screw in before the fuse.  They have holes in the center sized to match the center area of the plug fuse contact.  Smaller amperage fuses have smaller center areas, hence once in place these will not allow a larger fuse to be screwed into the panel and used.  These are very thin and colored to match the fuse, and can not be removed without a special tool.  The benefit of these is they allow any standard fuse sizing (type T)  to be used.
  • there are also rejection bases, but these do require specialized fuses to be used.  These will be Type S Fuses.
• use proper sized fuses in all sockets
• use slow blow or time delay on motor circuits such as furnace or air-conditioner or sump pump.  (it should be noted that a slow blow or time delay will only allow extra current to flow for a fraction of a second, and is rated the same as a regular fuse of the same ampacity for constant current flow)

There are however some definite advantages to breakers.

• they can easily be reset
• they can not be replaced easily with an incorrect or oversize protection device - essentially idiot proof
• they can be installed as GFCI or AFCI devices (with fuses you need to installed these at each receptacle)

The downside to breakers.

• you will find more double tapping on them due to the method of wire attachment
• they can, they do and they will fail (they are a mechanical device with moving parts - given time they all will eventually fail - some have failed to trip and have caused fires )

 

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So are fuses better ? 

Well, we had fuses in our home for around 20 years, and never blew a single fuse.  Having said that, I think I have only tripped one breaker and I was working on the circuit at the time.

But realistically, while fuses in theory are perhaps safer if used properly, I would say the best solution for the average homeowner is a breaker panel.  It takes no additional knowledge or understanding other than how to reset a tripped breaker.  It takes no preparation or planning to have a flashlight with batteries and spare fuses on hand.  They are pretty much idiot proof. 

And finally, your insurance company will feel more comfortable.  While there is really no solid reason other than mentioned above, insurance companies hate uncontrolled risks.

In closing - it is a good idea to operate your breakers occasionally, perhaps once a year.  Manufacturers indicate this can prolong the breakers lifespan.

The Consumer Product Safety Commission (CPSC) estimates a circuit breaker’s life expectancy at 30 to 40 years, and it is the same for GFCI, AFCI, and standard breakers. Because a breaker is a mechanical device, a humid outdoor location or the corrosive atmosphere of a room where pool chemicals are stored, for example, will shorten the lifespan.

 

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Wells Home Inspection Services