Electrical Panel Parts and Inspection

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We take a look at the parts of a typical electrical panel and what to look out for when assessing them for repair or replacement.

In our last blog, we examined how electricity moves from the utility lines into your home’s electrical panel.  Now we’ll take a look at the electrical panel itself.

An electrical panel is the heart of any building’s electrical system.  It helps safely distribute the electricity coming from the power lines outside.  An electrical panel also ties the many circuits in your home together in one central location.  Let’s take a quick look at some of the parts of an electrical panel.

Wiring a Breaker Box - Diagram

An electrical panel with its cover removed.

 

Photo credit: familyhandyman.com

Double Pole Service Disconnect

At the top of the electrical panel is a large switch.  This is commonly referred to as the “main” or “main breaker,” though its technical name is the double pole service disconnect.  This controls the electricity coming into your home via the two 120-volt wires from the electrical meter.  This switch turns all the power in your home off or back on.

Hot Bus Bars

From the double pole service disconnect, each of the 120-volt lines passes into its own bus.  A bus is essentially a metal bar.  Each hot bus runs vertically along each side of the electrical panel.

Neutral Bus

A third bus, called the neutral bus, receives electricity that comes back to the panel after it has flowed through your home’s grid and done its work.

Circuit Breakers

The familiar circuit breakers are set between the hot bus bars.  Each circuit has two hot wires and a neutral wire.  All of these exit the electrical panel and provide the electricity for their circuit.  Each switch is usually labeled with the name of the room or major appliances it runs to.  If there’s an overload, the circuit trips the switch and disconnects the current.

There are two main types of breakers.  Single pole breakers have one switch.  They can handle 120 volts and can be either 15 or 20 amps.  Double pole breakers, as you might expect, look like two switches joined together.  They can handle 240 volts with amperage ratings from 15 to 70.

Grounding Wire

Typically a bare copper wire, the grounding wire connects the neutral bus to a metal water pipe or metal rod buried in the earth.  Grounding prevents electricity from traveling to metal surfaces they weren’t intended to reach.  As you can imagine, this is a very important safety measure.

The electrical panel is, of course, an essential part of an electrical system’s operation and safety.  This means that keeping it in good repair is essential.

Most of us don’t think about the electrical panel unless something in the house stops working.  But like all the equipment in our homes, the electrical panel must also be inspected periodically.  Well-made electrical panels can last a long time without needing to be repaired or replaced.  That said, there are some signs that it might be time for you to do so.

  • The service-entrance cable (the line running between the structural mount on your home and the electrical panel) is damaged or loose.
  • Rust stains or chalky, white corrosion is evident on the electrical panel box or wiring.  If there is water on or near the electrical panel, stay away and call for professional help immediately.
  • Underpowered or overcrowded electrical panels can become a problem if you’re adding on to your home’s electrical grid.  An experienced electrician can help determine if you need more room or power for your needs.
  • Improper wiring or poor manufacturing can pose problems.  Again, these are issues that only a good electrician can really spot.

As the last two items show, it’s important to consult an electrician when dealing with your electrical panel.  While the electrical panel is not a very complex device, the components can be delicate.  Most importantly, electricity can be dangerous!  An experienced electrician knows how to safely handle these devices.

As we’ve mentioned in previous blogs, upgrading a portion of your home’s electrical grid – even one as important as the electrical panel – doesn’t mean rewiring your whole house.  The regulations governing electrical systems change around every three years.  It would be impossible to bring an entire system up to the current code every time a repair or replacement  is needed.   Because of this, electrical repairs must only meet the codes in effect at the time the house was built, not the codes currently in place.

Most of us certainly have no idea what these codes are now, much less what they were when our home was built!  A good electrician will be able to determine these and suggest only the rewiring or replacements you need.  As with any important purchase, it’s always best to get more than one price or estimate to make sure you’re getting your money’s worth!

If you think your electrical panel should be inspected by an experienced electrician, McCauley Electrical Service is just a call or email away.  Give us a call at 678-362-2881 to discuss your electrical panel or any other electrical need.