I will shortly be installing 2 water features on a 230volt supply from a c/u in my shed... Is it ok to use a 10Amp mcb?....or should i rate higher due to starting surge (pumps) firstly, and is it ok to parallel the pumps through a 20amp Double pole switch?.......Lastly is 1.5mm2 supply cable sufficient as i'm led to believe 1 pump has a 3amp running rating....??
Hi and thank you for using Just answer.
Per your question, you need to look at the pump. On every electric device there is an AMP rating. In your case there should be two. 1] a "start up" 2] continuance run. To find out how many amps you'll need, use the "wattage" number. In your case use the "higher" of the two. For example it might have a 2000 watt start-up or surge but it might have a 1400 watt continuance running. Take the 2000 watt and divide that into the voltage you are using. In this case we are talking 230 volts. That answer would be 8.69565217. So since they don't make 9 amp breakers, you would up-size to a 10 amp. As for the wire size, you would have to look at the wire it's self. A solid strand carries less amps than a braided wire would. Every wire is rated for the max load it is design to carry and it states right on the wire it's self. If you are saying that a 10 amp breaker would work, then the combined wattage of the motor should be no more than 2300 watts. Just remember copper out does aluminum any day.
I hopes this helps. If you have any other follow up questions, please ask. I wish you the best.