Mike Dolt Enterprises
Mike Dolt Enterprises
User: erickench, Location: Brooklyn, NY
Asked on: Thursday, April 14, 2011 at 7:33 pm EDT
Answered on: Tuesday, May 14, 2024 at 4:13 am EDT
Question: Look at this question and the answer as given by the answer key.A panelboard has four bus-bars and a nameplate with the information 3-phase, 4-wire A.C. 208/120V. If a lamp test set is to be used to determine which of the bus-bars is the neutral, you should for safety reasons, useA. one 120-volt lampB. two 120-volt lampC. one 120-volt, 300-watt lampD. two 120-volt lamps connected in seriesThe answer as given by the answer key is 'D' two 120-volt lamps connected in series. I assume that this so because you may have to test across two phases at 208 volts and a single 120 volt lamp would not be able withstand that.
Yes, that is correct. The reason why the answer is 'D' is because you may have to test across two phases at 208 volts and a single 120 volt lamp would not be able withstand that. By connecting two 120 volt lamps in series, you create a 240 volt lamp which can safely test across two phases at 208 volts Flag for review