Pro/Forums - View Single Post - How much pump is enough? How much is too much?

Cathar · 12-06-2004, 11:41 PM

Took some time to measure the PQ curve of RD-30 at 18.0v.

I arrived at the following curve. Everything above 6LPM is measured. The curve below 6LPM is what I extrapolated as I ran out of vertical height. I'll have to set up the tubing test outside the front of the house on the ground beside the main entrance stairwall landing and run tubing up to the roof peak (2-story house) in order to get more height and get a firm fix on the pump's peak dead-head, but I reckon somewhere between 7 to 8mH2O will be pretty close, and is not going to alter the graph in any dramatic fashion. I tried to measure peak dead head at 17.0v, but it was also above 6.0mH2O.

So yeah, 18.0v for the RD-30 is still very, very strong, but with a (relatively) lowly 28-30W power draw in the "typical" 6-10LPM range.

This is one heck of a pump, with every single desirable characteristic you want, except for the voltage requirement. Strong, wide PQ curve, able to service both high and low restriction blocks. Very quiet. Moderate power draw. Fairly small (marginally larger than a D4).

I will do an "inline heat dump" test when I next get some time to complete the analysis. Still, even if it were dumping 100% of its power draw into the water as heat, this would still make the pump near ideal for dual-fan radiators or anything larger.

12-06-2004, 11:41 PM	#153
Cathar Thermophile Join Date: Sep 2002 Location: Melbourne, Australia Posts: 2,538	Took some time to measure the PQ curve of RD-30 at 18.0v. I arrived at the following curve. Everything above 6LPM is measured. The curve below 6LPM is what I extrapolated as I ran out of vertical height. I'll have to set up the tubing test outside the front of the house on the ground beside the main entrance stairwall landing and run tubing up to the roof peak (2-story house) in order to get more height and get a firm fix on the pump's peak dead-head, but I reckon somewhere between 7 to 8mH2O will be pretty close, and is not going to alter the graph in any dramatic fashion. I tried to measure peak dead head at 17.0v, but it was also above 6.0mH2O. So yeah, 18.0v for the RD-30 is still very, very strong, but with a (relatively) lowly 28-30W power draw in the "typical" 6-10LPM range. This is one heck of a pump, with every single desirable characteristic you want, except for the voltage requirement. Strong, wide PQ curve, able to service both high and low restriction blocks. Very quiet. Moderate power draw. Fairly small (marginally larger than a D4). I will do an "inline heat dump" test when I next get some time to complete the analysis. Still, even if it were dumping 100% of its power draw into the water as heat, this would still make the pump near ideal for dual-fan radiators or anything larger.