Is Grundfos superseal output active during pressure modes?

[EHB]

Hi,

I am having difficulty getting an answer to this question (from Grundfos) and thought maybe someone already knew. They keep answering different questions.

The pump is a Grundfos UPM 3. It has 3 internal modes (constant flow, constant pressure and proportions, pressure) and one external (PWM)

There is a connector they sell called a mini superseal. It only has 3 wires.
1) INPUT PWM
2) GROUND
3) OUTPUT

You may note that although the pump has a pressure sensor this data is not made available. Hence I am thinking of using ONLY THE OUTPUT with the pump in constant pressure mode. This would allow me to monitor usage and alarms (ESP32 based controller).

My question is simply “in constant pressure mode is the OUTPUT active?” The manual does not answer this question as it assumes simultaneous use of both INPUT & OUTPUT.

I do have an alternative exit strategy if it doesn’t, which involves fitting my own pressure sensors before and after the pump (which is stupid as the pump already has sensors) but will post that in the projects category if that project becomes real.

 

[JonathanM]

What are you hoping to get from the OUTPUT and what will you use it for?

 

[EHB]

What are you hoping to get from the OUTPUT and what will you use it for?

1) energy usage of the pump
2) alarm 1 (dry I think)
3) alarm 2 (blocked I think)
Those are all transmitted on one wire as described in the manual. I would then send that data over WIFI to a Raspberry Pi, that is already running Home Assistant and hence notifications of alarms on my phone/watch. That aspect is actually quite simple as I already have a Rasperry Pi running Home Assistant.

 

[JonathanM]

1) energy usage of the pump
2) alarm 1 (dry I think)
3) alarm 2 (blocked I think)
Those are all transmitted on one wire as described in the manual. I would then send that data over WIFI to a Raspberry Pi, that is already running Home Assistant and hence notifications of alarms on my phone/watch. That aspect is actually quite simple as I already have a Rasperry Pi running Home Assistant.

Is there any way to test the OUTPUT terminal to see if it is sending a signal?

 

[EHB]

Not safely without buying a super-seal, which is £26. The sockets on the pump are female. I could theoretically stuck an oscilloscope probe in and feel around but it goes up to about 80V. Assume the current is tiny but if I accidentally short it I bet I kill the pump.

In mentions in the manual that if the INPUT PWM signal is too low it ignores it (goes to internal mode) and says nothing about turns no off sensing, so I think it probably is fine.

I’m tempted to have a bash, because even if it doesn’t work I can still probably make it work by buying my own industrial pressure sensor(s) from AliExpress. Just a lot more complicated. As well as 2 pressure sensors (in and out) I’d have to add a transistor because the ESP chips are 3.3V whilst the pump controller needs 4 to 24V and drill two holes for the pressure sensors and create threads. Then will the pipe and sensor expand with heat differently and fall out…