How To Look At A House

McGarry and Madsen's home inspection blog for buyers of  

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What are the busbars at electrical panels made of?

Tuesday, May 11, 2021

Busbars for residential electrical panels are made of either aluminum or copper. They can also be brass, although we have never seen a home panel that utilized brass. Copper has higher conductivity than aluminum and a lower coefficient of thermal expansion, but aluminum has the advantage of being less expensive. 

    Both metals can oxidize (corrode) over time, especially at outdoor panels. But the difference here is that copper’s surface oxidation is conductive, while the aluminum oxidation is an insulator. To learn more, see our blog post How dangerous is rust and corrosion inside an electrical panel? 

    Also, we recommend Why is spray paint on the bus bars of an electric panel a safety defect? and What is a "bus stab" in an electric panel? and What does maximum sum of breaker ratings per stab mean in an electrical panel?

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Here’s links to a collection of our other blog posts about ELECTRIC PANELS:

What causes copper wires to turn green or black in an electric panel?  

What is the maximum number of circuit breakers allowed in an electric panel?

When should a corroded or damaged electric panel cabinet or disconnect box be replaced? 

What is a tandem circuit breaker? 

When did arc fault circuit interrupter (AFCI) breakers first become required?

Can an electric panel be located in a closet? 

Can an electric panel be located in a bathroom? 

Can you add circuit breakers by different manufacturers to an electric panel if they fit?

My circuit breaker won't reset. What's wrong?  

What is a split bus electric panel?

How do I identify a combination AFCI (CAFCI) circuit breaker? 

What does a circuit breaker with a yellow or white test button indicate? 

What is the maximum gap allowed between the front of a recessed electric panel box and the wall surface surrounding it? 

What are the requirements for NM-cables entering an electric panel box?

Why is a fuse box/panel an insurance problem for homebuyers? 

Why is bundled wiring in an electric panel a defect?

What is the difference between GFCI and AFCI circuit breakers? 

Why are old electrical components not always "grandfathered" as acceptable by home inspectors?

What happens when you press the "TEST" button on a circuit breaker in an electric panel?

What is a Dual Function Circuit Interrupter (DFCI)? 

What is the difference between a Combination Arc Fault Circuit Interrupter (CAFCI) and an Arc Fault Circuit Interrupter (AFCI) circuit breaker?  

What is the difference between "grounded" and "grounding" electrical conductors? 

What does it mean when a wire is "overstripped" at a circuit breaker?

Why is an old fuse panel dangerous?  

Who is the manufacturer of those "bad" electric panels?

   Visit our ELECTRIC PANELS page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.

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