Masport M5 max motor size?

[mrnorthshore]

I have 2 Masport M5 vac pumps. One is a 3 hp and the other is a 5 hp electric. (both pumps are the same)
I was wondering if anyone has ever put a 7.5 hp or a 10 hp motor on a M5?
Would it give me more CFM, Or are these pumps maxed out on motor size right now?
Thanks

[BreezyHill]

The M5 has a 5 hp in standard setup It could be spun faster to achieve slightly more CFMs but there is a point of diminishing returns where the pump is spinning faster than the air can come into the pump.

On a Variable Frequency Drive setup a pump is usually spun at 120% of normal speed to evacuated the system from zero to 15" and then the transducer that senses the vac level signals the unit to slow down and maintain the desired vac level.

End of spring I was checking out a customers new dairy vac system on a vfd and it was running at 37% speed to maintain just under 14". The pump was warm to the touch. I don't like my maple pumps to go below 165 or over 210. If over then more oil or a fan is used to cool the pump. Fans work better as I try to give as much oil to get the best vac level and find that to much oil can lead to the pump heating more as it works to move the excess oil.

The best way to add more capacity to your pump is to maintain your system as leak free as possible. Last season my standby pump became the primary for a couple days when a dripper plugged and the primary pump cooked. I ran 737 taps on a 5-6 cfm pump and maintained 24-25". It would have been higher had I found a drop that had pulled off a spout on the back side of a tree on a brook bank. The rest of the system was in great shape as I spent nearly all season looking for this leak and repaired nearly every leak in the system including double clamping several mainline joints that had tiny bubbles added to the sap flow.

IMO there would be no benefit to using a larger motor and over speeding the M5. I like to have a smaller pump on the system that can maintain the system when the system is evacuated. Large pump is for times when the system is first fired up and if the small unit cant keep up...like a leak is formed, or during heavy flow times.

It does take more Hp to run high vac but the motor specked out on these pumps is usually plenty to run at the max the pump can produce. I have a M3 that runs a 3 Hp that will be going on line next season. Late summer I will have tuned it to make all she will and I can tell you what the max amps she will need to spin her at max vac level.

Good Luck!

Ben

[mrnorthshore]

Thanks the the reply Ben. I kind of thought that it might be close to maxing out the pump with the 5 hp.
We have ours converted to a flood system so its working pretty good but we were going to add 1500-1700 more taps this summer for a total of 3000-3200.
Might be time to start looking at getting a bigger vac pump.
Thanks
Paul

[BreezyHill]

if you got another pump hook them to a manifold and you got their combined total.