The Home Inspection Book: A Guide for Professionals By Marcia Darvin Spada Copyright, Thomson/South-Western, 2003, Revised, 2006

Chapter 9 Inspecting the Electrical System 2 Chapter 9 Inspecting the Electrical System

Chapter 9 Inspecting the Electrical System 3 Chapter 9 Key Terms  Amperage  Branch circuit wiring  Bus bars  Circuit  Conductor  Electric current  Fuse  Ground fault circuit interrupter (GFCI)  Insulator  Junction box  Neutral bus bar  Ohm  Overcurrent protection devices

Chapter 9 Inspecting the Electrical System 4 Chapter 9 Key Terms  Raceway  Receptacle  Service drop  Service entrance  cable  Service lateral  Service lateral conductor  Switch  Transformer  Voltage

Chapter 9 Inspecting the Electrical System 5 Definitions Electricity Flow of electrons Conductors Wires Ohm Unit of electrical resistance Insulator Prevents shock Voltage Pressure through wires Transformer Reduces voltage Amperage Amount of current

Chapter 9 Inspecting the Electrical System 6 Above Ground and Underground Service

Chapter 9 Inspecting the Electrical System 7 Service Lateral

Chapter 9 Inspecting the Electrical System 8 Grounding  Electrical systems must be grounded  Connected to the earth to limit excess voltage from:  lightning  line surges  contact with higher voltage lines  Grounding ensures that overcurrent protection devices respond quickly to ground faults. Devices include:  main disconnect  circuit breakers  fuses

Chapter 9 Inspecting the Electrical System 9 Service drop system grounding

Chapter 9 Inspecting the Electrical System 10 Main Panel Board Main panel board Subpanels Grounding Bus bars Circuit breakers or fuses Main disconnect Branch circuit wiring

Chapter 9 Inspecting the Electrical System 11 Panel Board Circuit Schedule

Chapter 9 Inspecting the Electrical System 12 Main Panel Board with Circuit Breakers

Chapter 9 Inspecting the Electrical System 13 Commonly Used Fuses

Chapter 9 Inspecting the Electrical System 14 Inspecting the Main Panel Board, Main Disconnect, Fuses and Circuit Breakers  Inspection points:  Location of main and subpanels  Condition-rust, corrosion, cover, exposed wiring  Locate the grounding conductor  If grounded to metal water pipe, must be bonded  Note amperage service  If feasible, determine if service entrance cable is compatible with amperage rating  If main disconnect outside, check if watertight  If no main disconnect, determine if power disconnect with no more than 6 hand movements.  Check for proper fuse size

Chapter 9 Inspecting the Electrical System 15 Wiring Materials Wiring Materials CopperBX Cable Romex Cable Conduit Greenfield (flexible conduit) Aluminum

Chapter 9 Inspecting the Electrical System 16 Inspecting the Wiring  Inspection points:  Check that wires not hanging loose  Identify type of branch circuit wiring  Identify if aluminum wire connected to 15-amp breaker or fuses (safety hazard)  Note any knob and tube wiring as safety hazard  Note number of outlets; overloaded extension cords  Note any spliced wires in main panel board  Check if wiring size matches ampere rating in main panel board  Check for evidence of burnt wiring

Chapter 9 Inspecting the Electrical System 17 Junction Boxes and Outlets  Junction Box  Contains wiring and used for space for electrical connections  Outlet  Point on wiring system where current is taken to supply equipment  Receptacle  Connected to branch circuit wires that supply current to equipment  Switches  Open and close electrical circuits

Chapter 9 Inspecting the Electrical System 18 Junction Boxes and Outlets

Chapter 9 Inspecting the Electrical System 19 Ground Fault Circuit Interrupter GFCI shuts circuit Bathrooms Outdoors Kitchens Garages

Chapter 9 Inspecting the Electrical System 20 Inspecting Junction Boxes, Plugs, Switches and GFCIs  Inspection points:  Check visible boxes  Use circuit analyzer to check a number of outlets  Determine if plugs have adequate reading  Trip GFCI and check to see if in appropriate locations  Check receptacles to see if properly polarized  Check receptacle for open ground  Test wall switches  Note non working light fixtures  Check for electric heaters