Jebao DC12000 problem

[Ron Reefman]

I’m having a problem with the Jebao DC12000 pump. It is is use as an in sump return pump and feeds a manifold that feeds the return to the tank and a chiller that is plumbed about 20 feet away out behind the house. When I start it up it runs fine for awhile and then slows down after some period of time. It seems that at the top flow rate or 2 it slows down after anywhere from 15 minutes to an hour or more. At the 3^rd or 4^th speed it has run from 2 hours to as long as 24 hours before slowing down.

When it slows down it seems like it’s running at 50% or even 33% of normal. If I turn the pump off for a minute or two and then turn it back on it goes through the normal slow start up and runs fine for whatever length of time and then slows down again.

I have a spare pump, so I left the power supply and controller and just swapped out the pump and nothing changed. So then I swapped the power supply and controller and it still does the same thing.

Any ideas what is happening?

 

[787will]

IMO you have very high head pressure (manifold and 20ft to the chiller plus return to the tank!) at the end of the day the jebao 12000 is still a relatively small pump for that job and you are simply overworking the pump and it can't handle the job. Just my .02c

 

[kschweer]

+1. 20' is too much head for that pump. This is their head loss chart for the jebao pumps

 

[redfishbluefish]

I'm following along because I've been kicking around the idea of switching over to a DC return.

The head loss chart above tells me that these pumps are not "pressure" pumps. First off their scaling is a bit funky, but the 12000 goes from 3200 gph to zero in under 16 feet. I'm assuming a vertical pipe of the diameter of the outlet of the pump. So it's fair to say these Jebaos are not pressure pumps. Being ignorant of these pumps, is the slow start-up designed into the electronics, or does it just happen because the drag on the motor can't get the shaft spinning at full right away?

It looks like you've got a lot going on with your setup. If I understand correctly, your chiller is 20 feet away....so a total of 40 foot of pipe. Even if this pipe is horizontal, the frictional losses, doing hand-waving approximations in my head, would easily be a 30% drop, and that is being generous. To add to that, again assuming, your sump is below your tank, so you now have that head loss as well.

I'm just thinking that these little DC motors can't take the back pressure well.

Again, following along to see what others who are in the know might have to contribute.

 

[mcarroll]

Headloss
First, I can't say I totally disagree with the too-much-headloss opinions, based on the description of the installation. But let's consider the situation.

A forty foot loop to a chiller combined with the vertical head to put the water back in the tank sounds like a killer for almost any pump, but....

Just roughing in some numbers to this calculator (sorry for the destination; also Mag 24 was the closest pump I could find to yours, which may be somewhat stronger...their list of pumps is very dated) I get about 13+' of head-pressure loss. It's a 2400gph pump and according to the calculator you should see about 800gph in your setup, with that pump.

FWIW.

I don't think this adds up to your pump simply being "too small to work".

Power Supply?
Just to throw out a different opinion based on evidence the OP provided....

The fact that the pump starts out alright, but then dies or performance goes flat tells me there could be an issue with the power supply. Maybe it's getting hot and/or otherwise failing?

$0.02

-Matt

P.S. I've never even heard of Jebao except on R2R "group buy" threads that seem like they should be against the rules, but if it's possible without speaking Chinese I'd call the manufacturer and ask their opinion. Could simply be a defect in a new, very cheap product.