Grundfos Pump Domestic, Speed control

[notsure]

I'm making my own replacement for a boilermate 2000 controler. I need more electical information on the pump so I can work out how to control the speed on it. does anyone know where I can find detailed electical info for this not just "on off" it looks like the original controler used PWM to control the speed but I'm not sure how that is possible with a Induction motor.

 

[oz-plumber]

Don't thinks it possible with that pump, unless Grundfos make an actuator to switch between pump speed.
I doubt they would on a pump that size.

THe pump speeds on those pumps is manually selected.

 

[Deleted member 120897]

I don’t think that’s a pwm type, speed is set on the pump and not via the pcb?

 

[ShaunCorbs]

Nope fixed speed switch ontop of the pump with lines to identify 1-3

 

[Chuck]

It's been a while but I'm fairly sure that Boilermate 2000s just used on-off control for their pumps. I think they used solid-state rather than mechanical relays. You set the pumps to the appropriate 'high/medium/low' speed using the switch on the connector box on the side of the pumps to get the temperature deltas into the range specified in the installation manual.

Continuously variable speed controllers are available for induction motors. These so called 'constant V/f' controllers are quite complicated and hence expensive. I think that they would be overkill in this sort of system. TBH, the whole Boilermate system has always struck me as overkill...

 

[Basher]

It's been a while but I'm fairly sure that Boilermate 2000s just used on-off control for their pumps

It seems from the installation manual that 3 speed pumps were fitted, but a modulating pump for space heating could be fitted as an option - it's all in the bumf here:

https://www.heatingsparesltd.com/download/boiler_manuals/Gledhill/BoilerMate_A_Class_Design,_Installation_And_Servicing_Instructions.pdf

The modulating pump they used is a Grundfos UPR 15/50, which seems to have an extra wire for a control signal for the speed. I think that's an obsolete pump now?

Looking at current Grundfos info they seem to have migrated to low voltage pulse signalling, the detail of which is covered from page 17 onwards in the following link:

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwis8eCU26SAAxX0XEEAHQFDDx4QFnoECA8QAQ&url=https%3A%2F%2Fapi.grundfos.com%2Fliterature%2FGrundfosliterature-5439390.pdf&usg=AOvVaw0O5WOpNTbZ_0q7NF-UCUms&opi=89978449

So notsure - the control signals you were unsure about are defined in the German standard mentioned in the above, and for a proper solution you would need a modulating pump designed for the purpose, not try to control the mains frequency for an ordinary pump.