Clutch Pump Voltage

[stillbuilding]

I have a 2" Jabsco 12VDC electric clutch pump (from previous boat).
Can i use this pump with 24 VDC? I know many small motors are fine with both voltages but this is different animal. Expensive item to burn out.

[CharlieJ]

Nope.

[Lancerbye]

The speed of most DC pumps is determined by the voltage so your pump will run very fast for a short time. You could however determine the current required at 12 volts for your pump and place a high wattage resistor in series with it, to drop half the voltage. Sometimes a lamp will be used in series for this purpose. So you can run a 12 volt motor from a 24 volt source if you take the actions required to drop some of the voltage in the circuit.

[Tellie]

Perhaps stillbuilding has worded it wrong, an electric clutch pump itself is not electric driven but engine driven. If so he's refering to the clutch voltage. I beleive the field coil can be replaced with a 24VDC coil. But if it is what we suspect a 12volt motor driven pump then depending on what it is used for it should not be hard to wire it for 12VDC from the battery bank.

[bobconnie]

If you have 24 volt power you have 12 volt power!! ya just need to wire it properly! ya could if nessary, go direct from one 12 volt batt to the pump with a fuse , or use a Voltage drop, which would be better in some ways ! but as long as you have dc voltage of 12 24 or 36 volts you can get any thing ya want ! dc is dc, just needs to be properly distributed, just my 2 cents

[Cheechako]

I assume the clutch is 12v not the pump right? How about a big automotive ballast resistor to bring the voltage down.?

[tuberider]

i see people take 12v from a 24v battery setup all the time, but it will cause an unbalance in the charging system. the only true way to derive 12v from 24 volt system is with a battery equalizer. it will balance the batteries during discharge, and will provide for an equal charge to all of the batteries connected to it.

[Blue Stocking]

Heres a novel idea. Use a 24 to 12 reducer.
I use them all the time to operate 12v electric door locks fitted to 24v euro trucks.

[Florida Mike]

A couple ways of doing this. You can center tap your batteries, as said before a lot of people do this in a sense this is most probably not use often shouldn’t cause any significant problem. Another way is a little more complicated but basically you can start with a car headlight in series with the clutch and check the voltage across the clutch. Your car headlight generally has two elements in the (IE highbeam and lowbeam). By connecting them either in series or parallel or maybe even just one you can get a pretty big resistor is not to delicate. Just my two cents, Mike.

[stillbuilding]

Yup, it is the clutch which is 12V. The pump attaches to the main motor.
I understand that I can use a 24V - 12 V converter and indeed will have 12VDC available. Just trying to keep it simple and most of the boat is 24V.
Thanks for the ideas.

[Lancerbye]

Since it is a clutch the most common way to fix this would be to get a 24 volt replacement magnetic coil for your clutch. Nothing extra to worry about. Most electric clutches have replaceable coils available in 12 or 24 volts. Easy to replace.

[Blue Stocking]

Originally Posted by stillbuilding

Yup, it is the clutch which is 12V. The pump attaches to the main motor.
I understand that I can use a 24V - 12 V converter and indeed will have 12VDC available. Just trying to keep it simple and most of the boat is 24V.
Thanks for the ideas.

24 to 12 converters are readily available in most automotive stores, at quite reasonable prices, eg a 30amp 12vdc for less than $100.
Transpo/WAI build a whole range.

[stillbuilding]

Thanks for the feedback. Gives me good options.
Better to run thru 24v panel so will try changing the clutch voltage first and use converter if no success.