pumps - direct drive vs. belt? & 3hp vs. 5hp motors?

[trs246810]

I currently use belt driven cat 310 pumps w/3hp motors, but I see direct drives out there...and I'm just wondering if there are any advantages? Also, where does the 5hp over the 3Hp really make a difference in a self serve setup? I purchased a used K O Manufacturing setup with 5hp direct drive cat pumps. I'm just wondering if it would make a good upgrade?...or if I should use the KO setup in a future application.? I know very little about K O's reputation. ~Justin

 

[MEP001]

The only advantage to direct drive is space. They're actually less reliable than belt drive because the pump has to spin at 1750 RPM instead of only 800-900.

If the requirements of your setup only necessitate 3HP motors, 5HP has no advantage. Most manufacturers upgrade to 5HP because the cost is minimal and it "looks" better because they're more powerful. In my 20 years of operating several and servicing many washes, I've seen no difference in the life expectancy of 3HP vs 5HP in a 3HP requirement. Some professionals in motor production will say that more HP than you need is bad, because the extra energy used is wasted as heat and shortens the life of the motor.

A direct drive Cat 310 pump (actually Cat 30) does require 5HP.

 

[trs246810]

Thanks

I really had no idea, but it does makes sense...thanks for your time Mep.

 

[galen]

?

Wrong on all counts. First a cat direct drive is a 340. Second, less reliable? I've had Cat 340's for 22 years. Third, mine are 3 hp motors.

 

[trs246810]

well...thanks

lol...well, thanks for not making me feel as bad for buying a couple 350 direct drives...and a couple 4SF45EL cat pumps...the 4SF45EL cat pumps look much diff than the pumps I'm used to seeing. I think this just goes to show how much I don't know...and still need to learn/experiment with. thanks, Justin

 

[Gabriel]

And now comes the million dollar question. I have often wondered--what Cat Pump is actually the best suited and most reliable pump for Self Serve Car Wash application. I know what I think, but the sad part is that I do not have that particular pump. What say you !!!!!!!!!!!!!!!!!!!! I pose this question just for information and educational purposes, not for WAR.

 

[trs246810]

You have to tell us what you think it is Gator?...yes, even if you don't have it!...although I'm wondering how you came to this conclusion if you don't have one.

 

[phred113]

It is hard to believe a direct drive pump would last as long as a belt drive, however there are stories of 30 year old belt drive pumps still operating, even though most of us are fixing or replacing pumps several times in that period. Given how long a motor lasts, paying extra for a 5 HP motor seems unnecessary.

 

[dreese]

Elect motor HP

Actually, motor HP is determined by the amount of output you want from your pump. (GPM x PSI) / 1460 = needed motor HP. Therefore, if you want to pump 4.0GPM @ 1200 psi ( 4800/1460 = 3.28) requires 3.28 HP.

 

[phred113]

Actually, the real formula is 4800/1714. The 1460 divisor is provided to cover inefficiencies in motor, pulley, and pump. Most washes do not use #07 nozzles or operate at 1200 PSI, so a 3 HP motor can run just fine with a little service factor useage. In my experience the pumps, usually Cats, are pully driven at a ratio to provide 3.5 gpm in reality - well below the 3 HP threshold.