Electrical Wiring in the Home/Power at light


Hi hope you can help i installed a small pull switch on a cfl light fitting fed from a photocell.When i put my tester to the incoming side it read 220 volts it should read zero in the daytime to prove my point i connected a small globe to the supply and it came on however the cfl fitting did not come on, that night the light did come on i am stumped as to why there is 220v everything is working fine any advice you could give give would be appreciated.
Kind regards

You can't just put a tester to one point and get a voltage reading. Voltage is the difference in potential between two points. What two points give you a voltage difference of 220 volts? South Africa uses the European model, probably based on a 230/400 volt WYE.

Also, be aware that if you are trying to learn electricity by reading info from the USA that we use a different voltage gradient in our residential distribution system. We also use a single phase distribution model to power residences.

Why would it read zero in the daytime?
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Electrical Wiring in the Home

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Robert Wilber


Licensed Philadelphia electrician serving Delaware, Chester, Montgomery and Philadelphia County in Pennsylvania. I install and repair residential, commercial and industrial wiring and lighting. Troubleshooting and repair of problems that stump other people is my favorite. I am willing to help people figure out why things don`t work. I understand motor controls, transformers and machine wiring. I do not teach basics to novices or do free design work.


Experience in the area I have 44 years experience in residential, commercial and industrial electrical construction and repair, 480 volts and below. This is not to be confused with one week repeated two thousand times.

44 years experience in residential, commercial and industrial electrical construction and repair

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