Two speed pump humming only on one speed - Help

[Dagnabbit]

Hi,

I have a two speed Hayward Flo-Max XL pump hooked up to a solar panel. Yesterday I turned off the pump while on high speed and while the water was backflowing into the pump from the solar panel, I turned on the pump again. At this point, the pump would only make the humming/nngghh noise with no waterflow, but when I switched it to low speed it worked fine.

I tested both capacitors with a digital multimeter set to 2000 ohms and with the power to the pump off.

Run capacitor (Genteq 97F9613, 35UF):
For just a second the readings are high (a few hundred) and drops to 007 where it stays. When I unplug the two electrical wires from the capacitor, there is no readings on the multimeter.

Start capacitor:
I only tested this one with the electrical wires on (but power still off). This one also spiked at a few hundred and dropped within a second to 040 where it stayed.

I am not sure how to fix the problem as I'm puzzled low speed works fine while high speed doesn't. Would a broken capacitor cause this behavior or wouldn't low or high speed work at all if a capacitor was bad? Or could I have broken/jammed something inside the pump?

I'd appreciate any insight.
Michael

 

[mas985]

You can't test a capacitor while in circuit. Remove the leads short the terminals and test again. At first the resistance should be very low and then climb to infinite.

A start capacitor could cause the problem as well as the centrifugal switch.

 

[Dagnabbit]

I checked both capacitors with the multimeter set to 2k Ohms, removed the leads and shorted the terminals. There was no resistance measurable on either, so it sound like they both went bad?

Could the pump really work on low speed with both capacitors dead? That's what it seems like, unless I am measuring incorrectly, but it seems really straight-forward to measure.

 

[mas985]

So after your shorted the terminals and then removed the short, the meter should have read 0 ohms and then risen slowly to infinite ohms.

Are you saying the meter read 0 ohms or infinite ohms from the start? Did you wait long enough?

 

[Dagnabbit]

The meter showed a 1 in the display before I touched the terminals and remained at 1 when I touched them both. I tried multiple times for about 5 seconds every time and also shorted the terminals in between my attempts to nullify any built up. Hopefully that makes sense, otherwise let me know and I will try to explain it better.

 

[mas985]

A 1 or an I?

If you touch the leads of the meter together, they read 0 correct?

 

[Dagnabbit]

I think it looks like a 1, but I took a picture so you can see what it looks like. I appreciate your patience troubleshooting my experience with multi meters and capacitors .

When in "Idle" mode or when touching both terminals on the capacitor it looks like this:




When I touch the leads of the meter together it looks like this:

 

[mas985]

Ok, that could just be how that meter displays infinity. They all are a little different. So if you never see a 0 when you touch the capacitor leads, that means it is open circuit and not working. But to make sure try a little higher scale even the max scale.

 

[Dagnabbit]

I tried increasing the Ohms in increments all the way to full scale, and the display kept showing the 1/I digit in the photo above for both capacitors, so I went on a 45 minute drive to a pool shop with the right equipment. They measured the run capacitor as defective and the start capacitor at 63.75uF (it's rated at 64uF -0% +20%). They suggested replacing both capacitors, but since the start capacitor is so close to it's uF rating, I'm thinking I could try replacing the run capacitor first and if it works, I don't have to replace the start capacitor (it shouldn't break the new run capacitor even if the start capacitor is bad too?).

It's still weird that I don't get an Ohms reading on the start capacitor, so I might have to get better equipment to measure capacitors with in the future.

Mark, thank you for your time. You have been very helpful.

 

[mas985]

If the motor isn't starting then I would suspect the start capacitor too since the run capacitor does not kick in until the motor is started and if it were bad, the motor would still run. The terminals on the capacitor could be flaky and connect sometimes and disconnect others. If you don't mind two trips to the motor store, you could just try the run first.

 

[Dagnabbit]

I'll try the run first and see what happens. I'll leave note in there if I get it working again (and likely also if I don't ).

 

[Dagnabbit]

I just wanted to end this thread by saying that the pump works again.

I put in a new run capacitor and that fixed it (I didn't replace the starter capacitor). I tested the new capacitor with my multimeter, but the reading was exactly the same as before - an I/1 in the display with no other values before or after I touched the leads. Apparently with my multi meter the Ohms are just not showing, thus I can't use it to check capacitors.

I appreciate the help I got here.