How to Look

at a House

A blog with answers
to your questions about

More blog posts about electric service and distribution:

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

  2. How can I tell if the electric outlets are grounded?

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

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

  5. Why do you pay so much attention to electrical safety?

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

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

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

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

  10. What is knob-and-tube wiring?

  11. What is a split bus electric panel?

  12. What is the right electric wire size for a home?

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

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

  15. Is a bare bulb light in a closet alright?

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

  17. My bathroom electric receptacle/outlet is dead, and there is no tripped breaker in the electric panel. What’s wrong?

  18. What is a “missing twistout” at an electric panel?

  19. What is an “open junction box”?

  20. Is an ungrounded receptacle/outlet dangerous?

  21. Where are smoke alarms required to be located?

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

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

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

  25. What is the lock device on a circuit breaker for?

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

  27. Can wiremold be used at an exterior location?

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

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

  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. What are the most common defects with over-the-range microwaves?

  41. Can an electric panel be located over stairs?

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

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

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

  45. What could cause an extremely high electric bill?

  46. Why are extension cords dangerous?

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

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

  49. Why are electrical outlets and plugs polarized?

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

  51. When was the three slot (grounding) outlet/receptacle first required?

  52. When were GFCI receptacle outlets first required?

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

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

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

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

  57. What is a “backstab” receptacle outlet?

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

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

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

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

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

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

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

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

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

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

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

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

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.

    Many inspectors rely on a three-light tester for verifying that a receptacle is correctly wired. Unfortunately, there is a way to trick a three-light tester into confirming that a receptacle is grounded when it actually is not. It is termed a false ground, although electricians routinely call it a “bootleg ground” or “cheated ground.” When upgrading to a three-slot receptacle in a two-wire system without a ground wire, if you use a short “jumper” wire to connect the ground screw at the side of the receptacle to the adjacent neutral screw, the connection will deceive a three-light tester. This is because the tester can recognize that the new ground slot will accept the flow of electricity, but cannot determine if the ground and neutral are traveling along the same path.

    This wiring configuration can cause electrical shock, or damage equipment that utilizes a ground while operating. The electric shock potential is due to the fact that the ground prong in a cord is connected to the metal frame of the appliance. With a false ground, the frame becomes connected to the neutral instead, and any connection of the frame to a grounded object will result in current flow. If that connection is a person, there is the possibility of a fatal shock.

    Two different $300 plug-in receptacle circuit analyzers (Ideal Suretest 61-165 and  Amprobe INSP-3) will indicate the presence of a false ground. We prefer the Amprobe, shown below, but both are good. A simpler, although more time-consuming, test method is to open a couple of receptacles and check the wire connections for that jumper wire when examining three-slot receptacles in a pre-1960 house—after shutting off the breaker, of course.

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.


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