220 volts, not 200 volts ```Name: Vijay Status: Student Age: 20s Location: N/A Country: N/A Date: N/A ``` Question: Why do me measure ac voltage in 220/440 etc.,instead of 200 0r 400 volts ? Replies: Vijay, Electricity enters a house through the service entrance, consisting of two 120-volt lines and one neutral line which acts as a return path for electricity, completing its circuit. Voltage entering the house can vary by five percent (6 volts) from the norm of 120 volts, depending how close the house is to the electrical substation or the power generating plant. Thus, voltage may be listed as 115 or 125. This deviation is harmless, because appliances and lighting devices are designed to operate with up to 10 percent variation in voltage-12 volts for 120-volt service or 24 for 240-volt service. I hope that this answers your question. Sincerely, Bob Trach Click here to return to the Engineering Archives

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