Grundfos MLE 132E speed control

[Earmic]

We have a Grundfos for a domestic water booster application. Everything is set up for constant pressure, discharge pressure sensing and all appears okay, except we cant get the motor to run in "auto". We can run in manual at a constant speed, okay. But we try and go to control, the pump will stop. DI1 is set up as "stop". Now I've tried ground on DI1 as suggested, no change. 5V on DI1, still no change. We have discharge pressure reading, setpoint higher than pressure. Am I missing something simple?

 

[Earmic]

Presume constant pressure control is available in all versions of the above?.

Its an MLE132E with display. We also have one like the photo, but that is next.

 

[ShaunCorbs]

I see on the pump you should be able to see a pressure when it’s running correct ?

 

[Earmic]

I see on the pump you should be able to see a pressure when it’s running correct ?

Yes we can see monitored (controlled, discharge) pressure, setpoint, speed, etc. but the pump wont run when started.

 

[ShaunCorbs]

Are these figures on 0 when not running / off ?

 

[Earmic]

Are these figures on 0 when not running / off ?

What figures?

 

[ShaunCorbs]

Discharge / pressure/ flow ?

 

[Earmic]

Discharge / pressure/ flow ?

discharge pressure doesn't move except building use. The green eye is not turning, the motor is not turning. Setpoint is 90psi discharge pressure is around 65psi.

 

[ShaunCorbs]

Sounds like maybe the pressure sensor is blocked or broken as when off should rear 0mh / 0 psi

 

[John.g]

The discharge pressure changes with water usage?, does it change when running the pump in constant speed.

 

[Earmic]

Sounds like maybe the pressure sensor is blocked or broken as when off should rear 0mh / 0 psi

Discharge pressure is in discharge line, reading outlet pressure continuously. It is the controlled parameter. This pump will run in manual at a set speed. but when switched to normal it just stops. We are beginning to think there is an issue with the electronics in the controller itself since nothing we can do will make it run in auto (normal) to control, pressure. Unless we are missing something, which is one reason I am here. Several Grundfos techs have looked at it to no avail. My next step is to rip the vfd and control out and put in an ABB580. Will this motor run on a 580? I wonder if there is some priority wiring to look for?

 

[Earmic]

Discharge pressure is in discharge line, reading outlet pressure continuously. It is the controlled parameter. This pump will run in manual at a set speed. but when switched to normal it just stops. We are beginning to think there is an issue with the electronics in the controller itself since nothing we can do will make it run in auto (normal) to control, pressure. Unless we are missing something, which is one reason I am here. Several Grundfos techs have looked at it to no avail. My next step is to rip the vfd and control out and put in an ABB580. Will this motor run on a 580? I wonder if there is some priority wiring to look for?

Monday I will try again (since I can now get normal mode) to swap AI1 with AI2 and swap all control parameters to reflect new psi input. Also will try AI1 reading feet as in a tank level control. Change setpoint to a feet level. I‘ll update as time allows. After this if it doesn’t work, out comes the blue blade….