Variable Frequency Drive

[Dirtychuck]

I'd like to convert my current basic high pressure pump setup and add a VFD and pressure transducer to control pump pressure. I'm running Cat 310 pumps w/ 5 hp 3 ph motor controled by a simple motor starter contactor.

Has anyone done this? Is there any issues or things that I need to look out for?

Any advice is greatly appreciated.

 

[mac]

There are several manufacturers that offer this on new setups, but I don't see what you would gain if everything is working now. You would just spend a few dollars and a lot of time for something that most likely your customer would not notice.

 

[Dirtychuck]

I want to do this to mailnly protect the pump. I just had a bay freeze and ruined a pump due to overheating. This has happened twice this year and I am tired of throwing money away on pump parts.

I already have one VFD to use as a test, so first one won't cost anything but my time.

 

[jjw]

It's a lot cheaper to use a thermo relief valve in the loop. Bypass water temp goes up to 160 deg. the valve opens just like your thermostat on your car engine, and vents hot water to drain or if your open tank setup just dump it back into the tank. This brings in fresh water that's lower in temp to protect your pump. That it, simple. jjw

 

[thoffmanjr]

We use a GE AF-300 Mini with a pressure transducer. You would also gain by running your pump almost half the speed. If the bay frozeWe use a GE AF-300 Mini (made by Fuji) with a pressure transducer. Check with www.gexpro.com to buy them. You would also gain by running your pump almost half the speed. Our pumps run at 33hz while delivering 1000psi. There is also energy savings since we are not pumping extra water through the pressure relief valve. Mechanically your pump life should also increase since it spins almost half as much. If the bay froze the pump would probably run at less than 1hz and would protect the pump from burning up. That would only work if your unloader or pressure relief valve where set higher than your desired pressure setting on the VFD. Some states or power companies may also offer incentives to install them.

 

[jimbeaux]

Hi Thoffmanjr. I was wondering if you also run your larger pumps like the Cat 3535 with the vfd's. If you do, did you retrofit them or can you order them with the vfd's? Thanks, Jimbeaux

 

[thoffmanjr]

Yes we do. We have a couple of CAT 3545 feeding multiple functions. Top rinse, side rinse and mirror rinse. As the Springer Coax valves open and close the transducer/VFD combination varies the speed of the pump. We have also done it with Hydrocell pumps. To answer your question, we did our own controls work. Usually when you order a pumping system from one of the suppliers the motor controls aren't included and you are on your own. You could buy the VFD controls from a supplier with the experience and there are at least a couple in our industry that do a great job. I recommend GE or Fuji because with over 150 installed since '04 still batting 100% with not a single failure.