Breaking News
Home » Basic/Important Electrical Formulas » How to Determine the Number of Lamps in Final Sub Circuit?

How to Determine the Number of Lamps in Final Sub Circuit?

If it is decided the current rating and already cable installed according to the rating of final sub circuit. and we want to know that how many light point will be on this final sub circuit. 
Suppose for a normal lighting in a home,office or hall, the current rating of sub circuit or final sub circuit is 5Amp and supply Voltage is 220 Volts. then how many 100  Watt Lamps we can instal on that specific sub circuit.
 We can find the number of lamps  by using this formula.

 Related Search Terms:
How to Determine the Number of  Lamps in Final Sub Circuit?
How to Find/Calculate the Number of  Lamps in Final Sub Circuit?

JLCPCB - Prototype PCBs for $2 + Free Shipping on First Order
China's Largest PCB Prototype Manufacturer, with 290,000+ Customers & 8,000+ Orders Per Day
10 PCBs Price: $2 for 2-layer, $15 for 4-layer, $74 for 6-layer

About Electrical Technology

All about Electrical & Electronics Engineering & Technology. Follow , Facebook , Twitter , Instagram, Pinterest, YouTube, & Linkedin to get the latest updates or subscribe Here to get latest Engineering Articles in your mailbox.

Check Also

Introduction to Harmonics

Introduction to Harmonics – Effect of Harmonics on Power System

What are Harmonics and How to Filter and Eliminate it. (Manuel Bolotinha) Introduction to Harmonics …


  1. if we want to install both kind of lamps(florescent and incandescent) then what is the formula? and in case of florescent lamp why we multiply the ratings of lamps by 2??? plz feed back me at thanx in advance

    • if you want to instal both kind of lamps… Simply use ….<br />(Supply voltage * current rating of the sub circuit)/ ((2* power of fluorescent lamps)+ power of incandescent lamps)

    • How many are Fluorescent lamps &amp; incandescent lamps?

    • These are the minimum number of the different type of lamps which to be installed in your final sub circuit…. it is not important that how many will be florescent and incandescent lamps. because the above formula show the minimum number… So the above formula stat that you can install 4 lamps either florescent or incandescent…. but should be used both kinds of lamps….. mean this formula

  2. Pls can some one send a detailed wiring diagram of ring mains circuit for lighting points for me. Not power ring circuit but lighting ring mains.

Leave a Reply

Your email address will not be published. Required fields are marked *