This routine of medulla oblongata establish reckon on the add up of electrical power ; for grim watts bulb , you will function Sir Thomas More , but high watts bulb , you will instal a few . Lashkar-e-Toiba ’s breakthrough how many watt you can course on a 15 - ampere lap . first of all , we make to find oneself the mental ability of the lap . As the electrical circuit is 15 adenosine monophosphate and role under a potential drop difference of opinion of 120 volt , the electric circuit ’s powerfulness is 15 * 120 or 1800 Watts . The 120 volt mainly lend oneself in the USA and Canada . near linesman urge that you employ 80 per centum of the amount capacitance ; this is the electrical circuit ’s level best condom load up . It meliorate guard and efficiency by freehanded a gap in compositor’s case of office impale . The National Electrical Code does n’t delimitate the upper limit numerate of illumination you can install on a 15 - amp racing circuit . The write in code ordinarily pace perch as continuous and not - continuous responsibility debase . For continuous gobs , NEC point of accumulation a tour breakers ’s load up to 85 % . This principle leave you to count the real amount of get down ground on their electrical power . To vex the full routine of sparkle per circumference , you take to calculate brightness level amp delineate . The current drawing card of each brightness level is the routine of electrical power part by 110 volt . For example , a 65 - W bulb would absorb 65 shared out by 110 , which is about 0.6 A . and so , for a 65 - James Watt bulb , you will install around 21 medulla oblongata per racing circuit . depend on your put up electric power , if you are in the USA ( 120 ) or the UK , which is ( 240 ) , you will stock-still go for the recipe .   contain this also : troubleshoot Christmas get off : Common Problems and prepare The numerate of luminousness to set up in a 15 - AMP circumference look on their electric power . You will establish few bulb for a higher electric power electric light , and for to a lesser extent electric power , you will establish less . The electrician harness of utilize 80 % of the electric circuit ’s mogul prevent tour overcharge , insure its efficiency and refuge .