Blog Posts About Electric Panels and Distribution:

  1. My circuit breaker won’t reset. What’s wrong?

  2. What is the life expectancy of a circuit breaker?

  3. What are the most common homeowner wiring mistakes?

  4. Is the electric panel big enough for this house?

  5. What is a double tap at a circuit breaker?

  6. The electric panel is marked “Trilliant” and it’s all grey plastic. Is it alright?

  7. Why does that wall plug have push-buttons in the middle?

  8. How do the new tamper-resistant electric receptacles work?

  9. How come my generator hookup got tagged as defective by the home inspector?

  10. How dangerous is old electrical wiring?

  11. What is a three-way switch?

  12. Does this place have one of those “bad” electric panels I’ve heard about?

  13. I heard that aluminum wiring is bad. Do you check for it?

  14. How far apart should the electrical receptacles be placed?

  15. Is an ungrounded receptacle/outlet dangerous?

  16. What is reversed polarity at an outlet/receptacle? Why is it dangerous?

  17. Why does the bedroom have a light switch but there is no light in the ceiling?

  18. How far apart should kitchen counter receptacles be placed?

  19. What is the switch on the wall with only two pushbuttons for?

  20. What are those strange looking wall switches in houses from the 1950s and 1960s?

  21. How far apart should electric receptacle outlets be placed in a garage?

  22. What is a lock device on a circuit breaker for?

  23. Will the electric company remove branches rubbing against the overhead service lines to my home?

  24. Can multiple neutral or ground wires be secured under the same terminal in an electric panel?

  25. Why are Zinsco and Sylvania-Zinsco electric panels a problem?

  26. Can wiremold be used at an exterior location?

  27. What is the life expectancy of electrical wiring in a house?

  28. How can adding wood paneling or a wainscot create an electrical safety hazard?

  29. What is a false ground, bootleg ground, or cheated ground receptacle?

  30. What are the most common electrical defects found in a home inspection?

  31. What is an open electrical splice?

  32. Why is an old fuse panel dangerous?

  33. What does it mean when a wire is “overstripped” at a circuit breaker?

  34. What is the difference between “grounded” and “grounding” electrical conductors?

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

  36. How can I tell if a receptacle/outlet is tamper resistant?

  37. What is a Dual Function Circuit Interrupter (DFCI)?

  38. Will a GFCI receptacle that is not grounded still function properly?

  39. Does a home inspector remove the electric panel cover plate and examine the inside of the panel?

  40. Can an electric panel be located over stairs?

  41. Is a house required to have outdoor electric receptacles?

  42. What are the code requirements for NM-cable (nonmetallic-sheathed cable or Romex®) in an attic?

  43. How can I change a 240V circuit to a 120V circuit?

  44. Can old electrical wiring go bad inside a wall?

  45. What could cause an extremely high electric bill?

  46. How do I trace and identify each circuit breaker in my electric panel to make a circuit directory?

  47. Why are extension cords dangerous?

  48. What problems does having too many electrical outlets on a single circuit cause?

  49. How can I find out the size of the electric service to a house?

  50. What happens when you press the “TEST” button on a circuit breaker in an electric panel?

  51. How many electric receptacles (outlets) are required in a hallway?

  52. Why does painting an electric receptacle (outlet) make it unsafe?

  53. When were GFCI receptacle outlets first required?

  54. What is the difference between GFCI and AFCI circuit breakers?

  55. Why is bundled wiring in an electric panel a defect?

  56. Why are some electric receptacles/outlets upside down (ground slot up) in a house?

  57. Why is undersize electric wiring in a house dangerous?

  58. Why is a fuse box an insurance problem for homebuyers?

  59. What is a “backstab” receptacle outlet?

  60. What electrical hazards does a Ground Fault Circuit Interrupter (GFCI) not protect against?

  61. What are the right words for talking about a house electrical system?

  62. What does “listed” and “labeled” mean for an electrical component?

  63. What does it mean when I find buried yellow "CAUTION" tape when digging a hole in the yard?

  64. How far away should a sink be from an electric panel?

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

  66. How can I tell if the electrical service is 3 phase or single phase?

  67. What is the building code requirement for receptacle outlets at stairs and stair landings?

  68. Can a home surge protector be installed loose in the bottom of an electric panel box?

  69. Can a bare bulb “lampholder” light fixture be installed outdoors?

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

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

  72. What is the difference between an electrical receptacle, an outlet, and a plug?

  73. Should I buy a house near a high-voltage power line?

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Welcome to our blog!
We want you to be an informed homebuyer, and each blog post is a question that we have answered for our friends and customers over the years. Hope they help you make a good choice for your next home.

  To read about issues related to homes of an specific era or type of house, visit one of these blog posts:

What are the common problems to look for when buying a 1950s house?

  1. What are the common problems to look for when buying a 1960s home?

  2. What are the common problems to look for when buying a 1970s home?

  3. What are the common problems to look for when buying a 1980s house?

  4. What problems should I look for when buying a country house or rural property?

  5. What problems should I look when when buying a house that has been moved?

  6. What problems should I look for when buying a house that has been vacant or abandoned?

  7. What are the most common problems with older mobile homes?

  8. What should I look for when buying a “flipper” house?

  9. What should I look for when buying a former rental house?

While we hope you find this series of articles about home inspection helpful, they should not be considered an alternative to an actual home inspection by a local inspector. Also, construction standards vary in different parts of the country and it is possible that important issues related to your area may not be covered here.
©2015 - McGarry and Madsen Inspection. -

   Here’s the same panel with the mains, a total of four in this case, boxed
in red:

   Note the tiny stickers between them that say “MAIN BREAKER.” To understand a little better how this panel design works, lets look at the same panel with the deadfront cover plate removed:

   The red rectangle shows the one main breaker that controls all the bottom breakers (enclosed in blue), and the white lines show the route of the wires that go behind the top 240-volt breakers to electrify the bottom bus bars.

   The defects we commonly see with split bus panels that are still in service and now 40 to 60 years old are:

  1. Not all the main breakers are clearly marked. The little stickers have fallen off over time.

  2. A panel with six main breakers, each of which is 240-volt, has had a 240-volt breaker changed out for two 120-volt breakers, pushing up the number of necessary switch-throws in the top cluster to shut off all power to more than the maximum six allowed.

   Also, all of the original circuit breakers are now past the their estimated 40 year functional lifespan. So, if you have a split bus panel in your home and are not planning on replacing it anytime soon, consider at least replacing the original breakers as a safety upgrade. Arc Fault Circuit Interrupter (AFCI) breakers are now code-required for most replacement circuits, and will provide an extra level of fire protection—which is especially important in a home with older wiring. They detect any arcing or sparking in wiring that become frayed, damaged, or deteriorated, and trip to cut off the circuit—on top of the normal circuit breaker duty of tripping when too much current is flowing through the wires.

    The manufacture of split bus panels was discontinued in the mid-1980s and they are now just an interesting bit of electric wiring history. Up to six main disconnects grouped together in the same main panel are allowed, but we rarely see more than two.


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