Jabsco Fresh Water Pump Motor Fail

[S/V_Surya]

I have looked through the archives and have not seen much information on the Jabsco 36900 series pumps.

My problem is the motor does not have enough power to reach the 40PSI shut off required. I have replaced the motor 3 times due to it sitting there running and drawing power but not turning and thus overheating. I now watch it to make sure it does not stall. These motors come from china and are not serviceable (cheap). My solution was to drop the pressure to about 35 lbs to make sure it does not stall but actually opens the pressure switch. I have complained to Jabsco and acually got a new motor from them under warranty. The actuator turns freely and is not binding. I do admit I had the belt to tight at one point.

Just looking for collective wisdom and experiences.

[HappyMdRSailor]

Pretty telling that you have gone through 3 motors....

You have got to have a source problem not providing enough juice for the pump.. Looks like these things run at 8A, so you need #12 wire for your run up to 25'... 10awg if longer... I would go up a size because the inrush current is larger... Another possibility is your breaker going bad, or bad connections to the house... Check for a splice or takeoff to another load...

Let us know what you find!

[S/V_Surya]

Thanks
My boat is used and I have had it for 5 years. The pump seemed to work fine till last year wires not changed. Will check wire sizes but unless there is corrosion may not be it. Breaker is 15 amps and seems ok. Not sure hold it is. The wire run is not more than 15 feet.

[donradcliffe]

Measure the voltage across the motor terminals when it is running.

[S/V_Surya]

Thanks that is a good idea. I do have ampmeter and voltmeter on the 12volt system. Ampmeter on system when initiating pressurization is normal and as it gets closer to shut off pressure climbs to 14 or so amps. But before reaching shut off pressure motor stops and amp gauge pegs. If I dont turn off breaker I get to buy a new motor. It is at that point I need to take a voltage reading at the pump.

[HappyMdRSailor]

Originally Posted by donradcliffe

Measure the voltage across the motor terminals when it is running.

Smarty Pants...

Originally Posted by S/V_Surya

Thanks that is a good idea. I do have ampmeter and voltmeter on the 12volt system. Ampmeter on system when initiating pressurization is normal and as it gets closer to shut off pressure climbs to 14 or so amps. But before reaching shut off pressure motor stops and amp gauge pegs. If I dont turn off breaker I get to buy a new motor. It is at that point I need to take a voltage reading at the pump.

All Righty... Now we're getting somewhere! Fantastic info to start with... great job...

Like Don said, measure the voltage right at the pump when running... We want something close to your house voltage... See if there's a difference between startup V, and just before "run and hit the breaker V"

If it's lower... You are pulling MORE amperage than the motor would be at the full operating voltage rating... You say "normal amperage" draw when starting... 8ish???

There's got to be a resistance in the path somewhere, as the original wire sized for the 15A breaker should be large enough...

Your turn!