problem with cycle sensor

[steveh]

I have 2 wells and so I ordered 2 cycle sensors. I hooked up the first sensor to my well. It rapidly flashes 0.00 with no response from any of the control buttons. The troubleshooting guide says this means the pump is not running.
I remove the cycle sensor and the pump runs just fine. I put the second cycle sensor in the circuit and everything is fine. I set up the sensor and it is working as advertised.

What is the problem with the first cycle sensor? I don't want to try to install it in my second well until I know what is wrong.

I understand that when the well runs dry there is a drop in the pumps amperage draw and that sends the sensor into DRY and shuts down the power. What kind of drop in amperage actually happens when the well goes dry if you are seeing 5.80 amps when running normally?

[Cary Austin]

It maybe just a bad unit. If you are not getting 240V from L1 out and L2 out after supplying 240V to L1 in and L2 in, then the unit may not be working.  Check the voltage on L1 and L2 out and if not 240V request a warranty replacement.  You can see how it is suppose to work from the other unit.

How much the amps drop depends on several things.  If you have a way of pumping the well dry or pulling the pump up out of the water you can test it.  Otherwise just set it just below and as close to the running amps as possible like 95% of full load.  But generally a pump will drop about 50% in amps when pumping dry, as that is how much it takes to spin the motor even when there is no pump attached.

[steveh]

Thanks for the input. There is no voltage out of the cycle sensor so I will return for replacement from Amazon.

I did cycle the system to DRY and the amperage it showed just before shutting off was 3.88 amps. Good information to have. The reason I asked is that the amperage rises as my 1500 gallon storage tank fills up. The pump started out drawing 5.29 amps and as the tank water level rises so does the amperage draw of the pump. With 400 gallons in the tank it is up to 5.90 amps. I have the DRY setting at 5.03 amps now.

[Cary Austin]

The amps will vary with the flow rate according to the pump curve.  Unusual to go up with an increase in tank fill, but every pump is different.  Doesn't hurt anything and it sounds like everything is working good. 
Thanks
Cary