1-ph to 3-ph converter

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aucklander

477 posts

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#303055 13-Jan-2023 10:40

Hi there,

I got one of these generic 3-ph converters from Aliexpress (750W capacity) and I was wondering if anyone knows more about what the various switches can do? I mean the ones labelled X0, X1, X2, X3 ?

I am looking to add a foot pedal which will act as a "dead man switch", the motor needs to stop if I lift my foot off the pedal, I need both hands for the intended operation of this system and a foot pedal would be the best approach to have an emergency stop rather than reaching for the stop button on the device faceplate. I could have the pedal wired to cut power to the system (the single-phase supply to the converter) but the electronics inside might not like this approach too much?

Is any of these switches able to provide this functionality? These switches are not addressed in any way through the manual received or on instructions I could find on internet - this is pretty generic product, front panel might vary but base functionality and programming varies very little between manufacturers. To add to the mystery, they call them "sensor" on the label but the symbol used is actually for a switch. Then X2 and X3 are also shown separately but with a different context, referring to "encoder input" - what is that?

Also (less important) - could one of these switches be used to provide feed-back about the real rpm, like a tachometer, and have the real RPM displayed instead of Hz or some RPM which is calculated by the device based on the parameters you enter initially (you need to set the motor nominal voltage, nominal Hz, nominal rpm, nominal amps, etc)? Is this what the "encoder input" might be intended to do?

https://www.aliexpress.com/item/1005003772734119.html

MikeAqua

7785 posts

Uber Geek

#3020786 13-Jan-2023 10:58

Generally X0 - X3 would be for binary sensors for example a limit or float switch. The analog input would be used for something like variable RPM, temperature, pressure etc.

Encoder can be something like a rotary switch used to set RPM or similar.

Disclaimer: I'm not by any means an expert in this stuff but I have dabbled.

Your foot pedal is not really an emergency stop. It's a safety device for sure. But an estop has some very particular characteristics, one of which is that if the estop is triggered it has to be actively reset before it will complete a circuit again.

Mike

aucklander

477 posts

Ultimate Geek

#3020791 13-Jan-2023 11:19

OK, thanks,

so it looks like I could just experiment with these inputs and see how the converter reacts, it should not do any damage if I "shortcut" one of the X pins to ground, as a float switch or a limit switch will do exactly the same?. I agree with the definition of the emergency stop, I will re-word my request: I am after a "remote on/off" switch, not an emergency stop.

The motor has a worm gear (30:1) on it and my goal is to create a setup allowing me to wind a wire onto that shaft. This is not for electric windings, coils, transformers - the wire will be 2-3mm galv wire or stainless. If it works OK I will try to increase thickness to use 4mm, 5mm, etc; The force needed to hold the wire will require me to use both hands also for better control of where the wire overlaps over the previous layer, this is why I need to find a way to move the start / stop to a foot pedal.

larknz

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#3020826 13-Jan-2023 13:05

What voltage is the output, the diagram doesn't say. What is the starting current of your motor? Will this device be able to handle it. What sort of harmonic filtering does it have? These sort of devices can play havoc on the power system. It is very unlikely that you can legally connect this device to the NZ power system.

larknz

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#3020827 13-Jan-2023 13:19

Looking further the output voltage is 220v which means you will have to run the motor in star configuration. However there doesn't appear to be a neutral output which makes that a bit difficult.
With the questions you are asking I wonder whether you should be playing with this.
It also says that you could get 1000watt output for a 750watt input. So it is a device that can make power from nothing.

gregmcc

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#3020916 13-Jan-2023 17:56

X's are digital inputs (switch inputs), what each one does is depending on how it has been programmed, for example, one may be programed to reverse the motor, one may be a jog function no way of telling without the manual.

the Y0 could be a analogue output, but again the manual will be required

aucklander:

Hi there,

I got one of these generic 3-ph converters from Aliexpress (750W capacity) and I was wondering if anyone knows more about what the various switches can do? I mean the ones labelled X0, X1, X2, X3 ?

I am looking to add a foot pedal which will act as a "dead man switch", the motor needs to stop if I lift my foot off the pedal, I need both hands for the intended operation of this system and a foot pedal would be the best approach to have an emergency stop rather than reaching for the stop button on the device faceplate. I could have the pedal wired to cut power to the system (the single-phase supply to the converter) but the electronics inside might not like this approach too much?

Is any of these switches able to provide this functionality? These switches are not addressed in any way through the manual received or on instructions I could find on internet - this is pretty generic product, front panel might vary but base functionality and programming varies very little between manufacturers. To add to the mystery, they call them "sensor" on the label but the symbol used is actually for a switch. Then X2 and X3 are also shown separately but with a different context, referring to "encoder input" - what is that?

Also (less important) - could one of these switches be used to provide feed-back about the real rpm, like a tachometer, and have the real RPM displayed instead of Hz or some RPM which is calculated by the device based on the parameters you enter initially (you need to set the motor nominal voltage, nominal Hz, nominal rpm, nominal amps, etc)? Is this what the "encoder input" might be intended to do?

https://www.aliexpress.com/item/1005003772734119.html

tweake

2398 posts

Uber Geek

#3021068 13-Jan-2023 18:38

aucklander:

Hi there,

I got one of these generic 3-ph converters from Aliexpress (750W capacity) and I was wondering if anyone knows more about what the various switches can do? I mean the ones labelled X0, X1, X2, X3 ?

I am looking to add a foot pedal which will act as a "dead man switch", the motor needs to stop if I lift my foot off the pedal, I need both hands for the intended operation of this system and a foot pedal would be the best approach to have an emergency stop rather than reaching for the stop button on the device faceplate. I could have the pedal wired to cut power to the system (the single-phase supply to the converter) but the electronics inside might not like this approach too much?

Is any of these switches able to provide this functionality? These switches are not addressed in any way through the manual received or on instructions I could find on internet - this is pretty generic product, front panel might vary but base functionality and programming varies very little between manufacturers. To add to the mystery, they call them "sensor" on the label but the symbol used is actually for a switch. Then X2 and X3 are also shown separately but with a different context, referring to "encoder input" - what is that?

Also (less important) - could one of these switches be used to provide feed-back about the real rpm, like a tachometer, and have the real RPM displayed instead of Hz or some RPM which is calculated by the device based on the parameters you enter initially (you need to set the motor nominal voltage, nominal Hz, nominal rpm, nominal amps, etc)? Is this what the "encoder input" might be intended to do?

https://www.aliexpress.com/item/1005003772734119.html

you really need to find the manual for it.

this sort of gear is very very common, but every manufacture does it differently. i have 5 different brands of these at work and they are all different.

switches (x0-x3 inputs) are programmable, typically on/off, fwd/rev. you have the pot connecting for speed control, but can be used with other inputs. some will have motor thermal overload setting. i've used that as an emergency stop before. yours seams to be missing the braking resistor terminals.

rpm display is calculated from the motor specs you put into it. but its still what it thinks the rpm is. however usually slip compensation is activated if rpm display is on, so its a bit more accurate afaik.

SomeoneSomewhere

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#3021302 14-Jan-2023 14:57

Yeah, this is 100% by configuration. Unfortunately the cheap chinesium drives often have very confusing manuals.

For your desired use case, I would look at a sewing-machine-style variable speed foot pedal. This will allow you to speed up and slow down as necessary, rather than simply being on or off.

For emergency stop, you really want to cut the incoming power. These cheap drives don't have any kind of safety rated switchoff and there are all kinds of faults that could lead to your e-stop unexpectedly no longer working.