air conditioning sea water cooling pump

[superboots]

I have a webasto air con unit and the cooling pump has been damaged from water in the bilge. Its rated 240 volt ac. Could I replace the pump with a 12volt unit? What are the issues involved? The ac branded pumps are expensive - would prefer a cheaper alternative providing no problems likely.

 

[Norman_E]

There is no reason why a 12 volt pump should not be used. Just get one that pumps at least as many litres per minute as the original. You need it to come on when required and to achieve that the solution I would choose is to connect the coil of a mains voltage relay where the existing pump is now connected, and use it to switch in the 12 volt pump. A relay like this may be OK http://www.maplin.co.uk/p/30a-spdt-power-relay-240vac-n24aw

I have no aircon but my fridge is water cooled and to achieve decent water flow without too much pump noise I acually use a 24 volt pump running on 12 volts which slows it a bit. Good flow is achieved by having pipework a size larger that originally fitted as it was the half inch bore pipework which originally reduced the flow rate. Now the biggest restriction is the cooling coil on the compressor. When I rewired my fridge I actually obtained very good quality contacters from a fridge specialist in Marmaris to switch both the mains compressor and the low voltage pump.

 

[rogerthebodger]

I have a own built air con on my boat and use a standard industrial circulating pump.

This gives the technical details of the webasto pumps and you should be able to get one from a local pump supplier.

http://www.webasto.com/fileadmin/we...alogues/marine-catalogue-extraction-pumps.pdf

 

[superboots]

Thanks for the advice. Noise form the pump is not an issue. To run the ac I need to have the generator on but there is a possibility of shore power ac when I suppose I could notice some noise in the saloon.