ATO and triple sensor challenge

[Schrute66]

I had an ATO output set up using the Hydros diaphragm pump and the triple level sensor, backed up by an additional level sensor higher in the sump/return chamber of my small AIO tank. I found that there seemed to be a lag between the triple sensor going wet and the pump turning off, so much so that the backup sump-high sensor would also go wet before the pump turned off. I chalked this up to the volume of my AIO return chamber being relatively small, the output of the diaphragm pump relatively high, and perhaps some inherent delay in the signal and response between the triple level sensor and the pump. So, I switched to using a Hydros simple dosing pump with its much lower flow rate. This pump uses a different cable and different drive port (on the same Launch). Unfortunately, this hasn't solved the problem. Instead of the diaphragm pump running for about 20 seconds, the dosing pump runs for a couple of minutes, but it still over-fills the chamber past the triple sensor wet level, and past the triple sensor overflow level as well, before the pump is turned off. I was just sure that the slower fill rate of the dosing pump would allow the triple level wet state to reach the control and turn off the pump in a timelier fashion. Anybody have thoughts on this?

 

[Danny]

Does the backup sensor go wet also or just the triple level overfull. There is very little difference in the wet level sensor and the overfull on the triple level sensor. The compartment may be small enough that the delay between the wet signal and turning the pump off is enough to trigger the overfull also. In that case there is not much you can do other than disable the overfull on the triple level sensor. You can set a maximum run time on the ATO output and set run past max on time to off and set a alert level and it will send an alert if it runs to max on time and stops so if there is an issue with the ATO full sensor the ATO pump will only run for that long then stop and send you an alert so you can check into the issue.

 

[Schrute66]

Thanks Danny. I've moved the backup sensor around a bit but yes, it sometimes does also go wet before the pump turns off. I have some room to play with, so I've been moving it up a little higher in the chamber. About that max on time setting, it seems that if we hit that and it turns the pump off, it will never turn it back on again until we toggle the output to off and then back to auto. Is that your understanding?

 

[Danny]

Thanks Danny. I've moved the backup sensor around a bit but yes, it sometimes does also go wet before the pump turns off. I have some room to play with, so I've been moving it up a little higher in the chamber. About that max on time setting, it seems that if we hit that and it turns the pump off, it will never turn it back on again until we toggle the output to off and then back to auto. Is that your understanding?

Yes either the sensor has to go wet or you would have to use the override to turn it off and back to auto. Unless you are at the tank and can stop it another way I would not override it to on and then auto since if there is a communications issue once it is on you would not be able to get it back off without unplugging it.

 

[Jamie]

I have the same problem, and I think you are right about the cause. I'm running this set up on an AIO, so the return pump chamber where I am sending the top-off water is quite small. The pump turns off when the triple optical sensor is in the middle...but the bit of water that was already moving through the tube is almost always enough to then send it all the way up to the top sensor and read WET. Didn't take me long to disable all the messages it was sending me, I went ahead and ordered an additional single level sensor that I'll mount a little higher up and use that as a backup to prevent my ATO pump getting stuck ON.