# 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.

### Electrical Technology

1. Anonymous says:

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 live007messenger@mail.com thanx in advance

1. Electrical Technology says:

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)

1. Electrical Technology says:

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)

2. Anonymous says:

How many are Fluorescent lamps &amp; incandescent lamps?

3. Electrical Technology says:

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. shams says:

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.

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