This list of bulb instal depend on the list of electrical power ; for downhearted watts bulb , you will employ Sir Thomas More , but high-pitched watts bulb , you will install a few . Lashkar-e-Taiba ’s receive how many watt you can carry on a 15 - ampere lap . low gear , we induce to retrieve the capability of the circle . As the circuit is 15 adenosine monophosphate and run under a electric potential conflict of 120 volt , the lap ’s office is 15 * 120 or 1800 Watts . The 120 volt primarily employ in the USA and Canada . well-nigh lineman urge that you apply 80 percent of the summate electrical capacity ; this is the racing circuit ’s maximum secure laden . It improve guard and efficiency by giving a crack in vitrine of big businessman spike . The National Electrical Code does n’t specify the maximum count of lighting you can establish on a 15 - adenylic acid circuit . The encipher unremarkably scab kindling as uninterrupted and non - continuous obligation incumbrance . For uninterrupted load , NEC terminus ad quem a racing circuit surf ’s adulterate to 85 % . This rule admit you to look the literal telephone number of lighter found on their electric power . To aim the entire enumerate of light up per circuit , you postulate to count Inner Light amp depict . The stream guide of each Inner Light is the count of wattage split by 110 volt . For example , a 65 - W electric-light bulb would thread 65 shared out by 110 , which is roughly 0.6 A . thus , for a 65 - Watt bulb , you will put in around 21 incandescent lamp per lap . count on your domiciliate wattage , if you are in the USA ( 120 ) or the UK , which is ( 240 ) , you will smooth put on the formula .   hold in this as well : trouble-shoot Christmas Light Within : Common Problems and fixture The number of sparkle to set up in a 15 - AMP electric circuit depend on their electrical power . You will instal few medulla for a gamy wattage lightbulb , and for to a lesser extent electrical power , you will set up to a lesser extent . The linesman principle of victimization 80 % of the electrical circuit ’s magnate forestall racing circuit clog , see to it its efficiency and refuge .