Grundfos UPR 15- 60 X 18 - 'Re -Purposing' ?

Plumpplumber · Nov 28, 2019

I've got one of these pumps lying around which I liberated from a Keston Celsius boiler before consigning the rest to the tip. It's in excellent nick. My sister's CH pump (external to the boiler) has just give up the ghost so I thought I might fit the Grundfos and save a bit of cash - however - this Grundfos has no integral speed control so I'm guessing speed was controlled by the Keston PCB. The pump has the normal terminal block for Live. Neutral and Earth as well as a separate block which would have been connected to the Keston. Does anyone know how the speed of this pump would have been regulated? I was wondering if I could select speeds by means of appropriate 'switches' across the terminals - or is speed control more sophisticated? Seems a shame to bin a good pump for want of speed control.

Alternatively, could I simply buy the speed control part of a different model Grundfos pump and fit it?

Ric2013 · Nov 28, 2019

I'm not sure how old that boiler is, but I'm assuming it was a fixed speed pump with three speeds. Having taken an old Grundfos Selectric apart in my childhood, I can advise that it controlled the speed by running the current around the entire winding for the slowest speed, a small part of the winding (hence lower resistance/higher current) for top speed and somewhere in between for speed 2. There were three tappings coming off the windings which would connect to the selector switch. I cannot remember how the capacitor was connected, but suspect it is both relevant and needed for starting.

But this was the very old Selectric model. Yours may be different.

Good pumps they were. In fact I have a customer still running one!

garygvl · Nov 28, 2019

what model keston celsius was it off i'm assuming a c25 which had the dc input speed contol from the boiler electonics. tbh just buy a new pump its easier in the long run. the c45/55 pumps are a much bigger beast

Plumpplumber · Nov 29, 2019

Ric2013 said:
I'm not sure how old that boiler is, but I'm assuming it was a fixed speed pump with three speeds. Having taken an old Grundfos Selectric apart in my childhood, I can advise that it controlled the speed by running the current around the entire winding for the slowest speed, a small part of the winding (hence lower resistance/higher current) for top speed and somewhere in between for speed 2. There were three tappings coming off the windings which would connect to the selector switch. I cannot remember how the capacitor was connected, but suspect it is both relevant and needed for starting.

But this was the very old Selectric model. Yours may be different.View attachment 41664

Good pumps they were. In fact I have a customer still running one!

It would be a newer pump than the Selectric but very similar. The Keston C25 was installed 2003 - gave me nothing but grief for around six or seven years until I gave up on it and replaced it with a Worcester Bosch. Powering different windings would make sense - fridge compressors use a similar principle - kicking off on two windings and dropping to one once the motor's spinning (I think!) Googling a Grundfos UPR brings up very little - just Kestons - so it looks like it Grundfos supplied them with a stock pump minus speed control!
[automerge]1575014137[/automerge]

garygvl said:
what model keston celsius was it off i'm assuming a c25 which had the dc input speed contol from the boiler electonics. tbh just buy a new pump its easier in the long run. the c45/55 pumps are a much bigger beast

Ah! If there's DC input that might complicate things! There doesn't seem to be much in the way of 'gubbins' inside the terminal box - just the two terminal blocks and capacitor. I wondered if the Keston was supplying varying levels of AC current to control the speed but that would seem unlikely. Perhaps as Ric2013 suggests the Keston was simply accessing the different windings and switching between them according to demand?

garygvl · Nov 29, 2019

Plumpplumber said:
It would be a newer pump than the Selectric but very similar. The Keston C25 was installed 2003 - gave me nothing but grief for around six or seven years until I gave up on it and replaced it with a Worcester Bosch. Powering different windings would make sense - fridge compressors use a similar principle - kicking off on two windings and dropping to one once the motor's spinning (I think!) Googling a Grundfos UPR brings up very little - just Kestons - so it looks like it Grundfos supplied them with a stock pump minus speed control!
[automerge]1575014137[/automerge]

Ah! If there's DC input that might complicate things! There doesn't seem to be much in the way of 'gubbins' inside the terminal box - just the two terminal blocks and capacitor. I wondered if the Keston was supplying varying levels of AC current to control the speed but that would seem unlikely. Perhaps as Ric2013 suggests the Keston was simply accessing the different windings and switching between them according to demand?

edit. what i said last night was wrong . its the c45/55 pumps that have dc voltage control. the c25 pumps have their speeds changed automatically by the pcb putting ac voltage onto different windings as per Ric2013

Plumpplumber · Nov 29, 2019

garygvl said:
edit. what i said last night was wrong . its the c45/55 pumps that have dc voltage control. the c25 pumps have their speeds changed automatically by the pcb putting ac voltage onto different windings as per Ric2013

I phoned Grundfos and they said the pump is a 'special' they did for Keston and have no technical info on it (!!) - advised me to phone Keston (Ideal!) They said the speed was controlled by a resistor on the boiler PCB but if I put 240v across the pump it should run. Well, it doesn't. I pulled out the terminal blocks and underneath found what looks like the remains of a speed selector knob - a live switching to three separate points wired down into the windings. No knob fitted though! I thought I'd cracked it and tried powering it up to each point in succession. On one terminal the pump hummed but didn't move but that's all. The guy at Keston/ Ideal said the capacitor was purely for suppression (??) so I took it out of the equation - still nothing! Perhaps the pump is actually faulty, although I know for sure it was working when removed from the boiler and the shaft spins nicely. I've given up and will buy a new pump!

Thanks to all for help and advice. Just something that intrigued me!

John.g · Feb 21, 2020

garygvl said:
edit. what i said last night was wrong . its the c45/55 pumps that have dc voltage control. the c25 pumps have their speeds changed automatically by the pcb putting ac voltage onto different windings as per Ric2013

Neighbour has just got a Potterton Profile 18S system boiler installed and while browsing through his manuals I see it too has a Grundfos UPR 15-60 which it states is a two speed pump set to low but can be changed to high speed.
Just wondering do Grundfos make a three speed ONLY A rated pump without proportional and constant pressure control as a lot of users don't want these options even though obviously the fixed speed option can be push button selected. I have seen cheap three speed only pumps on offer but not from the more quality manufacturers.

Grundfos UPR 15- 60 X 18 - 'Re -Purposing' ?

Plumpplumber

Ric2013

Plumbers Arms member

garygvl

Plumpplumber

garygvl

Plumpplumber

John.g

Similar plumbing topics