New to the GP Forums... I need help with a Pond Pump - Water Feature!

[SunnySeattle?]

I will try and keep this brief though as informative as possible! Hopefully someone can help.

We have a small pond with a pump which runs the water about 30' up a slight incline then comes out at the top of the water feature running back to the pond. Here is the problem:
The pond quit working.
Checked power, found the VFD - A/C Drive had a code showing a bad capacitor. I was able to turn it back on and run the pond for about 5 minutes with regular flow before the VFD would shut off.
I replaced the VFD (Telemechanic Avitar 31 Single Phase 1hp).
It was installed by my electrician. He programmed it to the settings per the panel and the pump.
Turned it on, water will not flow. Increased speed at the panel, still nothing.
I disconnected the 4" PVC at the elbow / junction near the pump. Turned the pump on and water flows. Pressure does not seem quite as strong as it was, though is still pretty heavy flow. Reconnected the PVC and still nothing flowing to the outlet. Took a wet/dry vac (small one) and was able to create suction at the outlet. Turned the pump on and left the pump pushing water the the vacuum sucking for approx 15 minutes. Still nothing.

Bottom line, pump is pumping water though the water is not flowing. No known blockage - it flowed fine before replacement, no cracks between pond and outlet as water level doesn't change after leaving pump running for hours.

What could it be?? How do I find the issue? Is there someone who knows these and could repair?

We are located in Bothell WA.


Thanks!

Thanks!

 

[Waterbug]

I couldn't really follow the symptoms. I didn't understand about removing the PVC. I'm not sure if you suspect the VFD or the pump. How long has the VFD been in place and working or did it never work?

All I can do is suggest general stuff. I'd first bypass the VFD completely. If the pump worked fine you'd know it was probably the VFD. You really have to test the current at every point you could to see what was actually going on. The electrician can do that or for $20-30 you can get an ohm meter. Takes some learning. Learn or pay, way of the world.

Or if the pump continued behaving badly when bypassed it'd be the pump.

There's a small chance it's a combination of the VFD and pump. A pump takes a lot of power to start. Because of how a VFD works, and your observations, it could have an issue with that initial load. And pumps (motors) can have a problem and cause even more of a load at start up, maybe more than the VFD can handle. Talking about a bad capacitor made me think this, but that was in the previous unit which isn't relevant to any of this? I'm a little confused.

The bottom line is this type of issue is really hard to track down with text. Really have to be on site.

I'm not a big fan of VFD. More stuff to breakdown. I'm a little surprised the GFI isn't also tripping with all this. I guess that means that half of the VFD is at least working well.

 

[SunnySeattle?]

The pump is submerged. The 4" PVC from the pump extends up above the water surface then angles back into the ground. I disconnected the PVC at the angle portion to see if the pump was actually pumping water... and it is. (Just not sure about the volume of water the pump is pushing).

The VFD had fail codes and was replaced yesterday. Since the replacement, the water has not flowed correctly.

It seems like the VFD and the pump are working. Just cannot get water to push / flow to the outlet which is a slight upgrade and approx 30' from the pump.

I was told I would not be able to bypass the VFD due to the type of pump I have. It appears the new VFD is working correctly though.

Would there be a check valve at either end that could be the issue? If so, how do I find it?

 

[Waterbug]

I understand much better.

If a check valve was installed just before all this started then yes it certainly should be checked. The wrong direction would cause a total block. Given the vac test (great idea) I'd say it was installed right and it doesn't sound like that run of pipe is new. When a check valve fails it may impede flow but not stop it completely. Normal failure would be it doesn't shut off water in the backwards direction. Also I wouldn't expect there to be a check value anywhere given my limited understanding of your setup. Well, maybe they didn't want the water in 30' of pipe running back into the pump. That is a lot of pipe. In that case the check valve should be right after the pump. They could have buried it in the ground which wouldn't be right, but possible. A check valve would look like a fitting but larger diameter. Like a snake that swallowed a rat type thing. There's normally an arrow pointing in the direction the water should flow.

I think I see why you suspect the pipe running from the pump to the outlet. But the shop vac test showed the pipe isn't blocked, or at least not totally blocked. So when the pump comes on water does flow that 2 or so feet to the surface. And because the pump comes on is why you say the VFD is working?

My current (no pun intended) guess is the VFD isn't actually sending enough power to the pump. A pump will only push water so high and that's a function of how hard the motor can push or in this case how fast the motor turns. At the surface you could see a lot of water, but a foot or two more and the pump could stall. That's what I call it, the impeller still turns but it only has enough power to keep water in the pipe to what ever level it can. Wired direct the pump has maximum power and can push to whatever head it's rated. But the VFD's job is to limited power so maybe it is, more than it should. Or the max values entered into the VFD were too low for the pump. My guess is the VFD wasn't installed correctly. My first guess would be a mistake entering the motor parameters into the VFD. Or a mistake in knowing what kind of pump you actually have or its ratings.

The electrician installed this and then left with it not working??? New guess, this was the first VFD they ever installed. After the settings the output of the VFD has to be checked. I'd read up on VFD a bit, just to get a few buzzwords. Then look over the electrician's shoulder and ask some questions. "I see you're using a digital meter, I thought only an analog meter could be used to test the frequency". "What's the frequency now?" See how they react. Calm and informative answer, even if you don't understand it, maybe they know what they're doing. Idiots hate questions or if you question their knowledge. Someone who knows what they're doing has no reason to be defensive. Always give them a chance to fix their work, but you may need to bring someone else in.

What kind of pump do you have? I haven't run into one yet that couldn't be direct wired.

 

[blessedfamily]

I love your landscaping,very well done.

 

[koiguy1969]

VERY NICE! BUT,Like many of us.. the nice stream and such just arent practical for me. ENJOY YOUR BEAUTIFUL YARD!

 

[j.w]

Hi neighbor, I'm up in sunny Arlington, Wa.

SunnySeattle?

Very pretty pond and property! Hope you figure out your pump problem.

 

[Waterbug]

Kioguy, why not have a stream?

SunnySeattle, I'm such a nerd...I didn't look at your pictures...yes, very beautiful. Hopefully you can post more pictures after the pump issue is over. For a lush landscape I have to live vicariously through others.

 

[taherrmann4]

Great looking pond and stream, your landscaping really pops.

 

[superdaft]

Welcome to the forum, lovely looking pond and surroundings. :goldfish:

 

[Becky]

Welcome to the forums! :wave:

 

[sissy]

welcome to the forum and wow that is some great looking pond and hope you post more pics of it .

 

[addy1]

Welcome to the group!