Reducing power on a heating element 1

[aboynamedclint]

I am the chief engineer on a 150+ foot yacht which has a Jacuzzi installed on the top deck for the owner to use at his liesure. The Electricity provided to the bus by the Gensets is 208Vac, 3 phase, and the Main breaker in control panel is 3 phase as well. There is a 12 kW (rated for 230/400 Vac) heating element in the water stream to warm the water, which keeps tripping the thermal overload protection every time it comes on. It is also distorting the schedule 80 PVC pipework causing it to sag and bend down stream. The element itself is wired delta with each phase connected to 3 of 6 legs, and each leg bridged to another. The ground is connected to the case. How do I re-wire the element in a wye configuration to reduce the voltage/ power though the element? As I understand it, the element will use less power and take longer to heat the water, but will not trip the thermal protection. I've read this thread (thread238-135327) and these guys seem to understand this a lot more than me, I hope you can help!

 

[Skogsgurra]

Less worried now - can sleep at night again. I also see where I got it wrong - didn't see the colours. Looks perfect now.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[rovineye]

Looks perfect except for the missing washer on one terminal. Might want to correct that to keep good contact with the lug.

 

[burnt2x]

rovineye,
Sharp pair of eyes or nice monitor you have there! Small things can be a cause of a big problem like loose contact if the nut turns!