Are VFD required?

[Birster]

Hi, 

 

We have a VFD for our centrifugal pump and another one for the mixer in the still. Do we absolutely need VFD for the mixers on our fermenter and mashtun too? Is it only a crazy thought? 

 

Thanks, 

[Silk City Distillers]

Most VFD will give you:

Speed Control

Slow Start

Overcurrent Protection

Up to you if you need or want them.  Pumps are usually a no-brainer as the speed control is valuable.  We have one on the tun as well, helps to slow down the mixer when mashing smaller volumes.

 

[PeteB]

In my opinion, if the mixer in the still works well at 100% speed (60 Hz USA) then you don't need it.

 

A centrifugal pump flow rate can be reduced to almost zero with an inline valve on the discharge side, assuming there aren't particles to clog the valve if it is almost closed.

EDIT: I said above "almost zero" It is very important to keep some liquid moving through the pump otherwise the liquid will heat up and can boil. A friend of mine left a pump motor running for an hour or so with the outlet shut off. He opened the priming port and it shot boiling water in his face.

Since you already have them installed it is probably not worth removing them, as said above they give added protection.

[Birster]

Thank you for your inputs guys. For peace of mind we went ahead and purchased our 3 missing VFDs, we will try to cut expense on something else. Which is not an easy thing to find 😉

[adamOVD]

I bought a cheap 100$ Chinese VFD for my pump. hoping it would last a year, and figuring it couldn't hurt a pump. Right or wrong, I'm still using it 3 years later. Being able to reverse the pump flow (If you have a compatible pump type) comes In handy for me as well.

[MG Thermal Consulting]

You have to aware that the pump motor is non-overloading throughout the "operational range" you intend on using it.

Otherwise you could go off on motor overloads.

[Dehner Distillery]

Automation Direct is a great source for VFD's.

 

[barristerandbrewer]

I think VFDs (Lenze AC/Tech is our go-to), are absolutely necessary on everything you can put them on.

We use them for mash cooling pumps, reversible rolling lobe pumps, roller mill, agitators, you name it.

We have saved a motor that was improperly wired once because the VFD shut it down before it could fry the windings.

You can also use it as an easy way to add an emergency stop button away from your equipment.