Driving a VFD with another VFD?

[metiz]

I hooked up my spindle motor and configured the VFD with some very conservative settings...and it works! best €4 I ever spend haha. Thanks for all your help

[mactec54]

I hooked up my spindle motor and configured the VFD with some very conservative settings...and it works! best €4 I ever spend haha. Thanks for all your help

If the VFD can only be programed to 120Hz max then you will burn smoke your 400Hz spindle so don't run it to long or your cheap drive will be an expensive drive when you have to replace your spindle motor as well

[metiz]

How does a low frequency burn a motor? The inverter I got with the spindle motor (as a set) can be set with a pot from 0 to 400hz. I also set the drive for a low current and voltage

[mactec54]

How does a low frequency burn a motor? The inverter I got with the spindle motor (as a set) can be set with a pot from 0 to 400hz. I also set the drive for a low current and voltage

I guess you will find out the VFD Drive Parameters must be set to the 400Hz or the motor spec's for the spindle to survive

[metiz]

I recently found another VFD and I didn't want to spam another thread so I'm posting in this one. It's a Parker 650 series. Just as before I want to test this using my cnc spindle motor, but I have some questions...
The drive has an input rating of 380-460VAC, 3 phase. Can I do the same trick again and hook it up to single phase from L1 and L2?
I only have 230VAC at my disposal, but I have a stupid idea: Can I rewire a MOT, lets say 10 windings primary, 18 secondary, for 418VAC? According to the drive specifications, it has a built in filter.

[Al_The_Man]

How does a low frequency burn a motor? The inverter I got with the spindle motor (as a set) can be set with a pot from 0 to 400hz. I also set the drive for a low current and voltage

Due to their smaller diameter and iron content, The high speed spindles have very low inductive reactance at their minimum frequency and lower, going too low can cause too high current into a low inductive load.
The MOT will step up the voltage, but still single phase. You may want to puch the magnetic shunt out of the Tfmr if it has one.
Al.

[metiz]

Thanks for your reply. I was not aware. Are you saying that, if I want to use my spindle w/o load to test the drive, it's better to increase the frequency a bit? There is also a current limiter setting on the drive itself. For the MOT, Can I assume that, if I expect to draw x Amps of current, I can use a wire rated for that Amperage for the windings and be ok? Somehow I feel like I'm overlooking something. I could do a 4 and 7 winding primary/ secondary and get the right voltage range, but does that mess with the transformer function/ cause it to overheat etc?

[mactec54]

Thanks for your reply. I was not aware. Are you saying that, if I want to use my spindle w/o load to test the drive, it's better to increase the frequency a bit? There is also a current limiter setting on the drive itself. For the MOT, Can I assume that, if I expect to draw x Amps of current, I can use a wire rated for that Amperage for the windings and be ok? Somehow I feel like I'm overlooking something. I could do a 4 and 7 winding primary/ secondary and get the right voltage range, but does that mess with the transformer function/ cause it to overheat etc?

You have to set the frequency in the VFD Drive to suit the motor Frequency and other motor spec's like voltage Amps and RPM

[metiz]

You have to set the frequency in the VFD Drive to suit the motor Frequency and other motor spec's like voltage Amps and RPM

That's what I did last time

[mactec54]

That's what I did last time

So why the question ( Are you saying that, if I want to use my spindle w/o load to test the drive, it's better to increase the frequency a bit? )

[Muzzer]

Well, I suspect he was confused by your post #22.

As long as you correctly program the motor nameplate values for the voltage, current and frequency, it will set the correct V/f, max phase current (power limit) and max frequency. At that stage, you should be in no danger of burning out the motor, regardless of what you do unless you run it at very low or zero speed and high torque so it overheats.

I have a couple of these Xtraverts - mine are both 5.5kW. Made in NZ of all places but work fine despite that.

There's no missing phase detection on these. It's quite unusual on low power VFDs. The input circuit is just a 6 diode bridge rectifier, so you could connect the L & N to any randomly chosen 2 of the 3 inputs. You could connect two of them together to share the current a bit more evenly.

As for running one VFD from another, you could do it if you had to, but you'd want to fit a three phase inductor between the output of one and the input of the other. Alternatively you could use three individual inductors if you don't have a proper three phase inductor. I wouldn't recommend it if you don't know how to select the right inductor values but the question was asked.....

[mactec54]

Well, I suspect he was confused by your post #22.

As long as you correctly program the motor nameplate values for the voltage, current and frequency, it will set the correct V/f, max phase current (power limit) and max frequency. At that stage, you should be in no danger of burning out the motor, regardless of what you do unless you run it at very low or zero speed and high torque so it overheats.

I have a couple of these Xtraverts - mine are both 5.5kW. Made in NZ of all places but work fine despite that.

There's no missing phase detection on these. It's quite unusual on low power VFDs. The input circuit is just a 6 diode bridge rectifier, so you could connect the L & N to any randomly chosen 2 of the 3 inputs. You could connect two of them together to share the current a bit more evenly.

As for running one VFD from another, you could do it if you had to, but you'd want to fit a three phase inductor between the output of one and the input of the other. Alternatively you could use three individual inductors if you don't have a proper three phase inductor. I wouldn't recommend it if you don't know how to select the right inductor values but the question was asked.....

It has nothing to do with post 22 it would help if you new what you are talking about, what you have posted here is mostly incorrect