12v downlights

[i=p/u]

can you see any thing wrong with this telectrix, theres 33 downlights which will be switched from 4 switches and run off 2x 10A mcbs

20W / 12v = 1.6A x 33 = 55A am i lost here???

 

[telectrix]

if they are 20watt downlights, the total power is 33 x 20 =660 watts. at 230v that's 2.87A. ( you've worked out the total current at 12v)

 

[i=p/u]

so its well worth having these installed..... power price wise, these are all going to be dimmed aswell cheers, so you dont use the 12v in your calculation, thats just the transformer??

 

[telectrix]

you use your screen name, mate. I = P/U, or current = watts/volts.

 

[i=p/u]

so 12v has nothing to do with it

 

[telectrix]

it does if you want to know the current at 12v. each lamp is 20/12 = 1.667A at 12v. total current for 33 lamps is 1.667 x 33 = 55A, but thats at 12v. to convert this to current at 230 you get 55 x 12/230 = 2.87A

 

[i=p/u]

weird that one but thanks

 

[telectrix]

just to complicate it for you, in real life, it will be slightly higher than 2.87A to allow for losses in the transformers.