Local Mixer Speed Control

[Martindag]

Heya,

For one of my projet i building a control panel for 4 industrial mixer

i got 2 mixer that run on the same speed so its no big deal, simple ON/OFF control.

But the 2 other got VFD and the operator need to adjust the speed infront these mixer and need something like a potentiometer to decide which 0-100% speed suit the best for his mix.

Im planning to have possibly a Micrologix 1400 PLC on my panel,

Do you have any recommendation on what could be the best option
for this type of local input speed that would directly

So far i was looking to simulate a potentiometer into 4-20ma using resistor but still i was looking around if there could be other option more plug and play...

 

[sparkie]

I wouldn't think you "need" a PLC for this task. You can use the VFD's control wiring. Rather than "simulate" you could use an actual pot you mount in a KO on the cabinet door and varies the 4-20mA straight to the drive.

This would cut down on cost to the customer as well. The only exception would be if the PLC is a customer requirement or if there is some advanced monitoring/tracking/control you need to do with one.

 

[Cow]

I agree with Sparkie. If it's possible I would just run a cable back to each drive for the potentiometer. I don't see any reason to include the PLC in this unless there's something I'm missing??

 

[Martindag]

the problem my cabinet is a little far and my operator specificly asked to have the analog control on the mixer directly to see himself the batch and the speed he need.

i searched a little bit, adding on my tiny local control box a pot connected to these OMEGA TX802P Potentiometer Transmitter. could do the job ?

 

[Martindag]

ohhhh... ok i get it yeah... use a analog input on the drive directly that can take a pot
rather than going in my PLC and after that going to the drive. I guess it would be more simple and simply redistribute my speed into my PLC

 

[sparkie]

You would use something like this:
http://www.alliedelec.com/eaton-control-automation-10250t333/70058137/

You would want some oil/water resistant parts for the panel due to the fact it would be around water.

Are the drives mounted in a control cabinet or on a machine?

Your box should have a start button, a stop button and an Estop along with the pot.

How far away is "far away?"

 

[Martindag]

Good stuff yeah but will go with schneider product like XB4BD912R10K
most of my control are Schneider and Weidmuller stuff and i like them.

The drive will be mounted inside the cabinet yes

I will get a metal control box nema4 with a Start, Stop , E-Stop and the potentiometer

For the one without drive i will get a 3 button box instead of 4 i guess.

the closest mixer is like 5 feets away and the fartest is 35 feets from the main cabinet.

 

[sparkie]

Good stuff yeah but will go with schneider product like XB4BD912R10K
most of my control are Schneider and Weidmuller stuff and i like them.

The drive will be mounted inside the cabinet yes

I will get a metal control box nema4 with a Start, Stop , E-Stop and the potentiometer

For the one without drive i will get a 3 button box instead of 4 i guess.

the closest mixer is like 5 feets away and the fartest is 35 feets from the main cabinet.

35 feet is no big deal for a speed control. The manual will tell you what size pot to use for speed reference.

 

[Martindag]

Ah true, just saw my 2 drive seem to need a different Ohm good thing you mentioned it ! thanks !

Quick question, what if most of the Eaton and Schneider Potentiometer you can get water proof are 10k but my drive need a 20k ?

im guessing its gonna be more complicated than adding a 10k resistor ?

 

[sparkie]

Ah true, just saw my 2 drive seem to need a different Ohm good thing you mentioned it ! thanks !

Quick question, what if most of the Eaton and Schneider Potentiometer you can get water proof are 10k but my drive need a 20k ?

im guessing its gonna be more complicated than adding a 10k resistor ?

Are you trying to scale voltage or current? Voltage would be what you would want to scale.

You may have to go with a different manufacturer.

There are a lot of factors to consider with a job like this as well. Perhaps you may want to consult a local controls guy or electrician on this one.