Putting an inverter on a motor.

[snipe]

Wanting to slow the intake pit down on the drier, anybody know a bit about motors. we are running on 3 phase. I have attached a picture or the motor plate.

 

[sjt01]

Use one of these:

AC Inverter Drives (400V) filtered by Power: 2.2kW (Page 1 of 13)

Electric Motor Speed Controllers for 400V Three Phase Supply filtered by Power: 2.2kW (Page 1 of 13)

inverterdrive.com

In their selection box, there are choices for power, or fan/pump power. Take no notice of fan/pump power as this cannot cope with starting loads of a conveyor or auger. I would be tempted to go one size or more up, say 3 kW rather then 2.2. Wiring is simple, but the settings instructions can be quite obtuse.

 

[Always wandering]

You can buy inverters with enclosure and all it takes is the three phases in and the three phases out really simple to wire up and operate . Check out invertek drives probably cost you £3-400 but very simple to install and also weather proof. Contact Betech and ask for Ben very helpfull and great prices

 

[snipe]

Thanks for the info, as always.

 

[335d]

How much do you want to slow it down by? using an inverter motor to lower the frequency to slow down the Motor is all well and good, but there are limitations. I wouldn’t recommend trying to go less than 50% speed, as the motor can have issues cooling at full torque. The motor is cooled by the fan on the end of the shaft, so slower speed means less air. If you require less than 70% a gearbox is best. Some inverters increase the motor voltage at lower frequencies to increase torque etc.
First thing I would do is check the motor Temperature as it currently is when fully loaded. Conveyors tend to get extended over time, and any random motor stuck on. If it is currently running cool enough, then you can try an inverter.
if you don’t need to vary the speed, or need soft start, I would look out for a gearbox. Less to go wrong, and one less control box in a dusty environment.

 

[jon9000]

We have on revert inverter on ours it works really well with a nice soft start I would recommend upgrading your existing motor as you will be running at a lower frequency

 

[snipe]

At the moment the feed conveyer runs for 45 seconds then stops for a few minutes till the dryer requires more grain, so I was thinking if it ran for a couple of minutes then stopped for a couple of minutes over heating won’t be a problem,...........I hope. Having the soft start an inverter would provide would be a benefit on the chains too.

 

[jon9000]

Ours works the same. Turning on and off under load is much better with an inverter

 

[jd6820]

Like others have suggested, just make sure that the motor is able to cope with the load at lower speeds. I agree a soft start is a good way to proceed if you want a less aggressive start but often not used on such a small motor. You are probably already aware but spec the inverter accordingly you can get inverters that output 230V rather than 415V so the motor needs to be wired accordingly or ensure the inverter spec'd is 415V and the motor wired in Star config if the nameplate indicates.

 

[snipe]

How do you make sure the motor is able to cope with the load at lower speeds, is it just as simple as it not getting too hot.

 

[sjt01]

How do you make sure the motor is able to cope with the load at lower speeds, is it just as simple as it not getting too hot.

First, if the load decreases with lower speed, you will be OK. If not you will need an oversized motor and inverter, and possibly a constant speed cooling fan for the motor (you will see this on some potato hopper drives). Some motors have built in thermistors to sense excess temperature.

 

[Deutzdx3]

With in the inverter parameters, there are functions for ramping up the starting speed, you can set it to what ever you like, regards to the motor, there are specific inverter friendly motors that can run at 30hz and up to 100hz so maybe try looking at a motor and inverter combination. We run inverters on all our machines to reduce start up load and give flexibility especially on our spray booth, we can balance the inlet and outlet easily.

 

[sjt01]

With in the inverter parameters, there are functions for ramping up the starting speed, you can set it to what ever you like, regards to the motor, there are specific inverter friendly motors that can run at 30hz and up to 100hz so maybe try looking at a motor and inverter combination. We run inverters on all our machines to reduce start up load and give flexibility especially on our spray booth, we can balance the inlet and outlet easily.

Fans and pumps are the easy targets for inverters. It is things like conveyors, mixers and the like which have to start with a load of material on them that are difficult with inverters, generally having to seriously oversize the inverter.

 

[snipe]

Just spoke to motor manufacture, they are happy down to half speed.