Delaval 78 max rpm?

[Woodsymiles]

Heard from a parts place for these pump that max rpm is 1150, but tag on pump plate lists a 10hp motor will give 1270 rpm...anyone know what the safe rpm is? Trying to size the proper pulley on motor to get a good safe rpm.

[pls009]

Please let me make the disclaimer that I am new to this and most likely don't know what I'm doing but feel like I should respond because I have this same pump body and just getting my feet wet. My tag says the same thing as yours. Hopefully, Breezy will chime in on this because he has the knowledge. My current set up has a 5hp motor and the tag says 800 rpm. From my limited testing, I have dialed my pump rpm down (3phase motor with VFD) to what I think is between 400-500 rpm's and am flooding it with quite a bit of oil and am achieving a vac of 27" and my pump is staying cool - maybe too cool though. I only mention my situation because I have wondered if I would really gain anything by running my pump at any higher rpms. I don't seem to gain any vac by running it at higher rpms. I'm guessing a lot of rpm versus vac levels has to do with how much oil you are giving the pump. My assumption is that what the parts place told you is a good starting point to see how it runs for you.

[pls009]

This website lists info for your pump too http://hambydairysupply.com/xcart/product.php?productid=17805 - they list a 6.5 inch pulley on the 10hp motor for max rpm of 1250

[Woodsymiles]

With getting 27" with the pump what's your specs? I'll be using a 5hp with the 1750 rpm from motor. A 6" pulley on the motor will give something around 1167 pump rpms.

[pls009]

I'm using a 5 hp 3 phase 460 volt motor that is 1725rpm, 60hz with a 4.1 inch pulley and the original 9 inch pulley on the pump. I'm flooding all 3 current ports where drippers were and also added an oil intake on the vac intake pipe. I have my VFD dialed back from 60 Hz to around 42 Hz. I'm not sure what my actual rpms are at but guessing lower than 800.

[BreezyHill]

Your rpm will depend on what your system needs to over come leaks. One vfd I used the Hz was directly releated to rpm...if 60 was 1250 then 42 would be 875; but another was dependent on torque and Hz and rpm were not relative.

1250 is fine for the pump, slower is just less friction heat and less cfm. If you don't need more cfms then run slower. I have a 75 spinning at 850 to pull 27. I can change the pulley in about 4 minutes if I need but it is easer to just plug in another pump. Yesterday we had a tree blow down in the storms the night b 4. Gauge was a little low so my son plugged in #2 pump and went leak searching. Found the tree had pulled of a drop on two taps.

IMO I would not flood bearings on a pump. The excess oil can lead to failures. Flood the inlet is fine as long as the feeder pipe is sized right.

[Woodsymiles]

Pls009 what do you have for taps and is land all level?

We have around 1000 and have an area with three sap ladders, a double 1" main line with 5 mains coming off from that. Below the sap ladders is three mains coming in. Most of the lines run up hill on a pretty steep grade so sap flows down hill for the most part.

Thanks Breezyhill for the info.

[pls009]

Sorry for the delay - been away from the computer.

We have 700 taps with expansion opportunities in the future. We have good slope. No sap ladders yet but hope to experiment with that in the future. This pump is currently more than I need (CFM) and that is why I had been running it at a lower rpm and it has also helped keep the pump cool.

Thanks for giving your advice on this Breezyhill.

[Woodsymiles]

Ok, thanks pls009 for that info, I don't have any vac gauges yet, coming in mail....but I have an rpm tester reading around 1100 on pump with the 6" pulley on the motor and it's getting wicked hot, I have blown a couple fuses and tripped the breaker once running it today, also the reclaimer does not have any hoses coming from it, there is a bung on bottom that I'm thinking of finding one that's got a hose barn on it and attracting one to the current oil system but not sure how that is going to work. I'm thinking the pulley on the motor is maybe too big and pump is getting over worked heating up causing it to bog down and bog down motor and causing fuses to blow....

[pls009]

I just put on a 2.6 inch pulley on my 5Hp motor this weekend and I think I'm around 500 rpm now with my electric motor running full speed at 60Hz. I bought a digital temp reader from Harbor Freight after Breezy recommended it - that is handy. My pump body is running around 140 degrees. I'm guessing that you need to get more oil into it somehow.

[BreezyHill]

140 is a nice cool temp but keep an eye on the condensation from the reclaimer. Drain daily.

I like to have a few spare pulleys of different sizes around. If My gauge is lower than I want I just put on a larger pulley on the motor. This increases the CFMs. Smaller reduces the CFMs. Run as slow as you need.

Today mine are running around 176-184. Warm but the ambient temp is 53.

Good Luck Guys!

[Woodsymiles]

I must be running too big of a pulley on the motor, it's 6" and pump will get so hot that it will burn your hand, it runs good for awhile than bogs down than blows fuses.. I increased oil flow and had oil coming out the top of the reclaimer, got vac gauge in mail and at releaser I'm pulling 22" or so, but still blowing fuses, even after increasing oil feed, thinking it's time to change to smaller pulley, sucks...because that 6"er with bushing cost $100, but smaller pulley will be cheaper and hoping will be able to reuse bushing on it.

[BreezyHill]

You need to find your local TEMPCO dealer. They have many farm size pulleys and they also have hubs that you can weld on the pulley size you want. I use them all the time with the feed mill. Slower moving augers move feed more efficiently than fast moving. Trick is to size the motor to the auger.

12" pulley and hub last year was around $30. At granger it was way more.

Also get a can of Never Seize...it is a silver lubricant to use on shafts and many other things. clean up the shaft with supper fine sand cloth or paper and put a coating of the Never Seize. Then you can slip the hub on and off a lot easier. No more pullers.

I would get a temp gun...hot to hand is only 125 to 135. 180 is like scalding water. This way you can see if you have a bearing heating up and stalling the motor.

Good for many other things too.

I would try a 4" and see what she does. You could be having the pump spinning so fast she is just making friction heat and this is heating the motor up and poping the breaker.

[Woodsymiles]

I'll see about Tempco, that would be a good idea on the heat gun and never seize, we use it at work so easy to find some of that. Yeah...have to figure this out before the season is over!

[Woodsymiles]

Doesn't look like we have a TEMPCO place around anywhere but I got a contact number online.