Somewhat newbie to 3 phase.

[Virtualflyer]

Hi all,

I hope someone can help/clear up some 3 phase circuit design problems i'm having.

I'm soon to be wiring up a new car garage and they are having some 3 phase heaters installed. They are 4500W each. I have an app that does electrical calculations and its saying its around 7 amps. I'm assuming thats 7 amps per phase? So i'm just a bit confused about what breaker i should use and then hence what cable i should be using?

If anyone could help i'd be very grateful.

 

[Andy™]

well something greater than 7a would probably be best...

 

[apprentice87]

Yes, it is 6.49 amps per phase. How many are there?? The problem is not finding a cable rated for the current, it is finding a cable that satisfies volt drop and EFLI requirements, so get your calculator out..

Never mind what breaker, how are you going to arrange switching so the customer can turn them on and off?? That is where the fun will start.. What if they want thermostatic control??

john..

 

[Geoff1946]

Wow that's going to cost a bit to run! Garage I use has a special oil heater that burns waste engine oil.