DC pump controller issue

[treesprite]

I'm wondering if disconnecting the cable from the controller panel will allow the pump to work without being affected by the controller feature. That's what I just did, but I won't know for a while if it fixes the problem of the controller slowing down the pump on its own. It's a Reef Octopus pump, but I can't remember the model, something with a 3 and some zeros and an S at the end

 

The controller buttons never worked when I bought the skimmer used, but it was okay because the pump was running full speed at whatever setting it was stuck on. Several days ago I discovered the problem with the pump getting slowed down (runs, but not enough to make foam). 

 

If I disconnect the power then reconnect, the pump goes normally for a while, then at some point in the day slows down again. I'm not sure what is triggering the slow down. I read that some DC pumps will do that if they detect a big change in water level, but my water level doesn't really change due to ATO. 

 

Finally I decided to take the box apart. I thought there would be a way to use the control buttons from the inside, but the inside of the front panel is somehow just completely smooth, but with a cable sticking out of it. The cable connects to the circuit board just like any computer cable, so I just disconnected it, closed the box back up and connected the power. The pump is working full power right now. I don't know how long it has usually been lasting, since I haven't had an opportunity to sit around all day watching it - I  don't know if it is an hour or half a day or variable. If anyone wants to save me the trouble of having to watch and wait and worry, you can just tell me right now if disconnecting the cable will have solved the problem.

 

Any advice, suggestions, feedback, etc is appreciated. Thank you.

Edited February 21, 2020 by treesprite

[Origami]

I can't tell you whether or not it will address the slowing down problem, but kudos for taking it apart and trying something different. If the front panel was beginning to fail, perhaps separating the (membrane?) keyboard / control panel from the board will prevent sporadic signaling from commanding the pump to slow down (if that was the problem).

 

All you can do now is just wait and see if it fixes things.

[treesprite]

It didn't work as hoped. I'm not sure how many hours it went. I can't afford a new pump right now. Using my old skimmer would probably be no better than just re-starting the power on this one twice a day with some hours of down time. 

 

The controller boxes are  one piece except the ends come off and the board slides in. I would have to disconnect the two power lines to take the board out, otherwise I'd be able to see if there is anything else simple enough for me to do. Maybe if I look harder, I can find some random post about fixing this thing, or find out how I could bypass the controller.

Edited February 22, 2020 by treesprite

[Origami]

I doubt that you can bypass the controller. They're integral to the pump operation, closing a control loop.

[treesprite]

Well, I got the board out without disconnecting the wires. I'm wondering if anything can be removed that would prevent the automatic behavior.

 

 

Edited February 22, 2020 by treesprite

[Origami]

It may not be the controller. I don't know exactly how your pump is designed, but a lot of them incorporate sensors in the pump body that provide speed, temperature and other feedback to the controller. The controller uses that information to control operation (speed, startup, etc.) and to respond to ooerating anomalies. If, for example, the speed sensor is sending back jittery speed data, the controller might interpret that as impeller imbalance and automatically reduce speed to prevent damage to the pump. It's hard to know exactly why the speed is dropping back unless it's documented somewhere in a user or repair manual.

[treesprite]

31 minutes ago, Origami said:

It may not be the controller. I don't know exactly how your pump is designed, but a lot of them incorporate sensors in the pump body that provide speed, temperature and other feedback to the controller. The controller uses that information to control operation (speed, startup, etc.) and to respond to ooerating anomalies. If, for example, the speed sensor is sending back jittery speed data, the controller might interpret that as impeller imbalance and automatically reduce speed to prevent damage to the pump. It's hard to know exactly why the speed is dropping back unless it's documented somewhere in a user or repair manual.

 

I will take apart the pump and see if something is wrong there.

 

I think I would rather have a skimmer pump that doesn't require a controller.

[treesprite]

 

This tiny piece of black plastic was in the impeller (size reference is the square of toilet paper it's on). Going on Tom's point of an impeller imbalance, I'm hoping it was just this making the pump slow down.

[treesprite]

The pump is still acting normal. I'm not sure what the longest time has been between the slowing episodes, but the last one was maybe only a couple hours. 

[treesprite]

Still going normal power. I think the piece of plastic was the problem. I didn't see it when I just looked into the top of the impeller from the end of the pump, because it was down in the bottom of the teeth where I couldn't see it without take the impeller completely out of the pump.

 

Thanks for educating me, Tom. This is the first time I've had a pump with a controller - I thought it just work like a variable switch, and didn't realize that it would be sophisticated enough to take this kind of feedback from the pump. 

[Origami]

Fingers crossed!

[treesprite]

When I left the house at 3pm, the pump was still full power. I'm pretty sure the problem is solved at this point. I have no idea where the little piece of hard, black plastic came from; I don't recall anything breaking that is made from that material.