How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manfuactured and modular homes
Are wall light switches required be up for on and down for off?
Saturday, July 14, 2018
The building codes have requirements for where a light switch must be installed, but we know of no code citation that says a light switch must be installed so that the “up” position of the toggle energizes the circuit. However, it is customary to do it that way for single-pole switches in the United States.
The U.K. is opposite: you normally toggle down to turn on a light switch. The issue is further complicated by 3-way light switches—the kind that, for example, are used to control the lighting for a stairs from both the top and bottom—and simply toggle from on to off, or off to on, when the switch position is changed.
We don’t write up a single-pole light switch that is installed with the down position as “on” in our inspection report, but do mention it to a homebuyer for two reasons:
- When the switch is installed backwards from what is standard in the U.S., other than a 3-way switch, it means that a professional electrician did not do the wiring and there may be further unprofessional wiring hidden from view.
- Once a prospective homeowner knows about it, they can choose to live with it, since it is not a safety defect, or have it reversed.
There are also three-way light switches that are used in pairs to control lighting from the top and bottom of stairs or opposite ends of a long hallway. The position of the switch does not indicate either on or off. Go to our blog post How does a three-way switch work? to learn more.
Also see our blog post How can I figure out what a mystery wall switch does?
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Here’s links to a collection of our other blog posts about ELECTRICAL WIRING:
• Which house appliances need a dedicated electrical circuit?
• Can a short circuit cause a high electric bill?
• What is the maximum spacing requirement for securing NM-cable (nonmetallic-sheathed cable)?
• Is it alright to just put wire nuts on the end of unused or abandoned NM-cable or wiring?
• What causes copper wires to turn green or black in an electric panel?
• What are typical aluminum service entrance wire/cable sizes for the electrical service to a house?
• Why is it unsafe to bond neutral and ground wiring at subpanels?
• Should I get a lightning rod system to protect my house?
• Why is a strain relief clamp necessary for the cord connection to some electric appliances?
• Does a wire nut connection need to be wrapped with electrical tape?
• What is the minimum clearance of overhead electric service drop wires above a house roof?
• What are the requirements for NM-cables entering an electric panel box?
• What is the color code for NM cable (Romex®) sheathing?
• Why is undersize electric wiring in a house dangerous?
• What causes flickering or blinking lights in a house?
• Why are old electrical components not always "grandfathered" as acceptable by home inspectors?
• How can I find out the size of the electric service to a house?
• Can old electrical wiring go bad inside a wall?
• What is an open electrical splice?
• What are the most common electrical defects found in a home inspection?
• What is the life expectancy of electrical wiring in a house?
• What is an "open junction box"?
• How dangerous is old electrical wiring?
• I heard that aluminum wiring is bad. How do you check for aluminum wiring?
• What is "knob and tube" wiring?
• What is the code requirement for receptacle outlets in a closet?
Visit our ELECTRICAL 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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