Thread: Choosing a VFD

Just some comments that others may have covered.
The wiring diagram states the main motor is "2 speed 3 phase". If the high speed is twice the low speed, the motor is quite likely a dahlander (pole-changing) design, but if the speed ratio is anything other than 2 it is not a dahlander type.
A dahlander motor (and likely any other 2 speed type as well) should stopped from the vfd before using the original switch to change speeds, otherwise there is a risk of destroying the vfd.

Discussions on PM about vfd/dahlander systems seem to favour wiring up a dahlander motor to only one speed and using the VFD for all speed changes, but having two machines like that myself I am not convinced it is the best approach. So far I have not damaged anything, but with increasing age and decreasing memory, one of these days I am going to forget to hit the vfd stop button and just flick the speed switch. Consequently I have decided to add some extra switching to the speed selector to ensure that the vfd gets a stop signal before the motor speed switch contacts separate prior to snapping across to the other speed setting.

Bill

Just thinking a bit more about the safety contactor aspect.

My initial thought was the same as Bob said - the VFD won’t start the motor up after power loss.
That’s definitely correct out of the box where you’re starting the motor with the (momentary) run button on the VFD.
How it would actually behave once configured for external switching control using the original lathe rotary switch - I’m not 100% sure.
You’d definitely want to test, as it will depend on whether the VFD sees the external switching already being in run mode when it boots up as an error condition, or if it boots up and then sees it as a valid mode and starts the motor.

Possibly that’s logic that can be configured anyway.

Steve

WCD, the manual is mostly in German but I've figured out the speeds are 1400/2800. My interpretation of the speed selector has a delta connection in one position and wye in the other with all the neutrals tied together. So I reckon it is going to be a dahlander.

I'd be interested in your solution for the speed selector.

I may be on a bit of a journey with the controls but I quite enjoy working this type of thing out.

I have also just found the recent-ish thread on the Ecogoo.

Originally Posted by OxxAndBert

Just thinking a bit more about the safety contactor aspect.

My initial thought was the same as Bob said - the VFD won’t start the motor up after power loss.
That’s definitely correct out of the box where you’re starting the motor with the (momentary) run button on the VFD.
How it would actually behave once configured for external switching control using the original lathe rotary switch - I’m not 100% sure.
You’d definitely want to test, as it will depend on whether the VFD sees the external switching already being in run mode when it boots up as an error condition, or if it boots up and then sees it as a valid mode and starts the motor.

Possibly that’s logic that can be configured anyway.

The first thing everyone should do when they get even a new VFD is to perform a complete factory reset.
Any VFD worth its money will then reset the "start on power up" to 'off".
I haven't come across any that have a factory reset with "start on power up" set to ''on".
This should apply to external as well as internal VFD switching

About the 2nd or 3rd brand new HY VFD I installed and turned on tried to crank the motor up to 600Hz. It got up to about 180 Hz before the VFD tripped out by which time both the VFD and motor were making a real racket.. Definitely not a factory default frequency for these HYs. Not knowing what other parameters had been played with I did a factory reset and it then ran just fine.

Along similar lines, recently a mate of mine bought a brand new 240V VFD and it would not correctly power a basic motor - it ran, but it had so little power I could easily stop it with my hand at 50Hz . After e checked a few things like was it set up as 240V ∆, it turned out that someone had set the motor/base frequency to 400Hz, but with a frequency limit of 50Hz.

If I hook 240V up to the lathe's terminal box then I can use the LV circuit to provide power to the VSD via the safety contactor.

Otherwise, as Steve says, use contacts in the run/rev switch as digital inputs and wire the VFD direct to the motor.

I could do similar for the high/low switch. Not necessary but I like the idea of the switch working.

If the motor protection is entrusted to the VFD then I'm tempted to bypass the inbuilt thermal. If these fail open for some reason then I expect it cooks the VFD. But I need to trust the VFD to do its thing otherwise I risk cooking the motor.

Originally Posted by browny

If the motor protection is entrusted to the VFD then I'm tempted to bypass the inbuilt thermal. If these fail open for some reason then I expect it cooks the VFD. But I need to trust the VFD to do its thing otherwise I risk cooking the motor.

VFDs are very good at looking after themselves and motors. What cooks motors is excess current so if current parameters are correctly set they will prevent this. In non-VFD controller motors a current limiting contactor switch is normally employed rather than thermal switches. If you wanted to your thermal switch could be built into the normal VFD stop/start circuit without any problems.

Here's what everyone has been waiting for!

That is a double star motor, it would work perfectly as is on a 3 or 4kw Ecogoo 380 volt drive.

Before I pull the trigger, does anyone other than Ecogoo do 240 to 415 VFDs?

From the other threads I got the impression that some of the casings on these cheap drives are pretty lightweight. I have lots of little fingers that touch everything in my shed. Is the Ecogoo well sealed enough to deal with kids and dust? Or should I count on putting it in a box of some sort?

Originally Posted by browny

Before I pull the trigger, does anyone other than Ecogoo do 240 to 415 VFDs?

From the other threads I got the impression that some of the casings on these cheap drives are pretty lightweight. I have lots of little fingers that touch everything in my shed. Is the Ecogoo well sealed enough to deal with kids and dust? Or should I count on putting it in a box of some sort?

I wouldn't worry too much about dust on a lathe.
However, if the terminals are exposed, code would say it should be in a box.

I would be interested to know if the output voltage is dependent on the input voltage. I have seen 220 plus or minus 10% with output of 380 plus or minus 10%.

If I put 240 in (QLD) that is about a 9% increase. That would be a 414V output.

Can anyone clarify this for me.

Thanks

Steve

PS apparently QLD is 240V whilst most other states are 230V, please correct if I am wrong.

Another member here SiJ mentioned previously that he's used some Nflixin brand ones which seem to be pretty much the same as the Ecogoo.
I've no personal experience with the Nflixin myself.

The little Ecogoo's (0.75-2.2kw) aren't the best for terminal protection - this style: https://www.aliexpress.com/item/4000976186585.html
IMO they probably should be in an enclosure.

The bigger ones are fine https://www.aliexpress.com/item/1005003636021791.html
Interestingly, there's also a 2.2kw version in that range, but they are $200 instead of about $140 for the little cheapie model.
I assume you're planning on getting a 4kw so should be one of this style.

The fans only move air through the heatsink at the back, so not circulating it over the internal components. I haven't had any issues so far with dust etc, but you need to consider the possibility of swarf or bird crap etc getting in the air slots in the top and onto the circuit board as that would likely be terminal for the board.
The VFD on my mill (not an Ecogoo one) sits behind the main electrical cabinet but I still made up a little guard/duct that prevents anything falling in the top.

Steve

Originally Posted by Reidy41

I would be interested to know if the output voltage is dependent on the input voltage. I have seen 220 plus or minus 10% with output of 380 plus or minus 10%.

If I put 240 in (QLD) that is about a 9% increase. That would be a 414V output.

Can anyone clarify this for me.

apparently QLD is 240V whilst most other states are 230V, please correct if I am wrong.

Output is proportional to input.

WA has 240V and at times it goes as high as 250V.

I've been using VFDs since 2011 and currently have nine 240V VFDs in my shed, with a cumulative 65 years of run time experience.
In that time I've damaged one VFD beyond repair (It was second hand from china that I put on a grinder) . It was my fault for setting the wrong deceleration parameter and it turns out I could not have set an appropriate parameter (coast to stop) as that was not in teh instruction set.
I've also installed or been involved with about 2 dozen other VFDs here in WA so also 240V - as far as I know they are all still running fine.

Data plate of the motor says it’s nominal 415V, you will not have a problem

Ok Ecogoo is ordered, will see what turns up in a couple of weeks.