Digi Phase Converters, 3 phase motors etc, Anyone?

As above, definitely a 2-pole machine.

You said earlier that when you were running the motor without load, it was going faster than you thought it should be, is this still the case when you change the pole number setting to 2?

How are you setting the speed you want? Is it by setting an RPM figure, or Hz?

To me it sounds like one of the inverter parameters isn’t set correctly, and that you are trying to run with too low a voltage for a given speed.

Just checking here, if you run the motor unloaded, what does the inverter say it’s output voltage is at full speed? And then at half speed? (It’s probably best to run this without any intermediate boost etc)

With the two voltages, the first, full speed one, should be double the voltage of the second.

Cheekyboy – the 220/380 means that it can be set up as either a 220V delta wired motor, or a 380V star wired motor. In both of these circumstances you end up with 220V being placed across each coil, because as you rightly pointed out for a star connected system running at 380V gives 220V phase to neutral, which is what the star point is.

Just checked the manual, and the pole/rpm settings are for user info only, and don’t actually affect the running of the inverter.

I’d suggest doing a factory reset on the inverter in case you/somebody else had changed some setting that shouldn’t of been, then change only the settings that need changed, which should only be the motor current (PD142). All the other default settings should work fine to test things, and then the only ones I’d be changing would be to configure the start/stop inputs as needed.

As for checking speed, just go by the Hz reading on the display. You can configure the poles/plate RPM so you can see the RPM on the display, but as long as the Hz is at 50, then the motor should be running at the correct speed (squirrel cage motors speed is directly related to the input frequency, so unless the frequency is wrong, the motor speed won’t change).

Also, what happens to the current when you apply load to the machine?
How much does it increase, or does the inverter go into current limiting mode?

your motor plate states 220/380 this means phase to neutral = 220v
phase to phase = 380v
if the output from your inverter is 220 phase to phase you do not have sufficient volts

220 x 1.732=380 (root 3 x 220)

Utter tosh, its a 3 phase motor hence the voltage is quoted in 3 phase, the Neutral doesn’t even figure in it.

mc
where do you see that pole and rpm settings are for info only. i can certainly change them and when running, the display shows the max rpm i entered.
for that matter, where did you find the manual to look at?

i tried a factory reset and it didn’t seems to do it.

not woried about speed any more. it’s clearly going at the right speed.

funkynick: “To me it sounds like one of the inverter parameters isn’t set correctly, and that you are trying to run with too low a voltage for a given speed.”

it seems like that to me too, but still can’t figure it out.
i’ll go check current under load etc

Just on the off chance this, its not a braked motor is it ?

Does the motor just look like a motor or is there anything else bolted to it ?

Look for a torque boost parameter, I am not convinced it should be in V/F mode either more like constant torque but without seeing the exact application its a difficult one.

don’t think so. no add-ons.

is V/F a changeble thing? in constant mode does it just clunk on and ‘force’ the motor up to speed?

Link to manual – http://www.jinlantrade.com/ebay/invertermanual.pdf
Although the inverter should of came with a nice thick paper version.

Did you follow the correct instructions for a factory reset?
Go to the correct PD number then enter 08?

PD141 upwards are the motor name plate settings. On a basic inverter like this, the RPM/Poles is only used to display the RPM (and pretty much says that in the manual, although not in the clearest of ways). I’m pretty sure on more advanced inverters with motor sensing (which I’ve totally forgotten the correct name for right now!), the settings are needed for the detection to work correctly.

Might be worth checking the key voltage values, to ensure all the voltages are indeed set to 220V.

thanks mc
yes did that for reset

aye, i’ll triple check those things.

Utter tosh, its a 3 phase motor hence the voltage is quoted in 3 phase, the Neutral doesn’t even figure in it.

I never said it did ………..fool ! I was stating the fact that 220v in a 3 phase config gives you 380v across phases.

I never said it did ………..fool ! I was stating the fact that 220v in a 3 phase config gives you 380v across phases.

Thanks, just have a scroll up, that’s it, keep going, there you go, see your post now ?

your motor plate states 220/380 this means phase to neutral = 220v

See that word Neutral that you used, you tell me what’s that got to do with a 3 phase motor ? Nothing, that’s what.

Trying reading what the op originally refers to

i bought a digital 1ph 220V to 3ph 220V converter on ebay to run a dual voltage motor, ie one that can does 380v or 220v .

Its not a dual voltage motor though is it !

Or do you think it is 😆

well looks like i’ve got it working!

setting Pd145: Auto torque compensation
factory setting 2%, moved it up to 4% and jobsagoodun.
probably put it up a bit more cos it still struggles with rip-sawing.

intermediate voltage is still up a bit. form factory 15v. 24v i think.

speed is fine. just faster that i expected! old machine fro 1978 = quality but not super smooth!

anyway, all good. delta wiring on 220v seems to be fine as my understanding of it suggested it should be.

and stop being children! just try to put your points so celarly that there’s no room for misunderstanding.

anyway thanks everyone. i’ve learned a lot.
jimmer

oh, and what kind of switch should/could i wire in?
the big red shut-of switches that a lot of machines have on them, they have some kind of current to them right? or are they just mechanical cutting live/neut connection?

would be nice to have something chunky and obvious.
anyone post a link to something suitable?

also, can anyone digest the circuit diagram better than me and tell me which of the control circuit terminals are for switching? is it just FOR (forward) for go and and RST (reset) to stop?

Its not a dual voltage motor though is it !

Or do you think it is

Sigh, that’s EXACTLY what it is, hence the nameplate states 220/380, the delta winding being 220V the star being 380V, plenty of motors are wound like this, its used by machinery manufacturers so they can make one motor/machine for different markets.

And he hasn’t bought a converter, he bought a VSD (Variable Speed Drive) which happens to take 220V single phase in and push 220V 3 phase out.

Go and have read about motors before you try spouting electrical theory again.

Cheers

also, can anyone digest the circuit diagram better than me and tell me which of the control circuit terminals are for switching? is it just FOR (forward) for go and and RST (reset) to stop?

Depends on how its programmed, could be use the RUN terminal closed for run, open it to stop it, RST is for resetting a fault generally

You can use whatever you want to really, just google Inverter or VSD wiring, plenty of examples to get you on your way

RUN ? I meant FOR….

Jamie,

Glad to hear you got it sorted, and I’ve heard that even some of the guys at my work just end up playing with the settings to get things to work sometimes… although I am surprised that the setting you used makes any difference when the motor is at full speed… but who knows when a manual is written so badly!

Just a thought though, how long is the cable to the motor? If it is too long then this might be why it wasn’t working well, and that the extra voltage is enough to get it running.

As for an emergency stop button, we always use normally closed switches which break on operation of the big red mushroom, but looking at the circuit for this it doesn’t look like there are any contacts for one of those. Couldn’t see anything which gave a description of what the reset does either… so in this case I’d think about having an external e-stop which cut the power to the unit instead.

Cheekyboy, I was trying to explain earlier, but obviously not well enough…

The motor has 3 windings, which can be arranged in a star or delta configuration, and to get the motor to run at it’s rated speed and torque it requires 220V across these windings.

Now, in the delta configuration this simply gives us a phase-phase voltage of 220V, and this is the situation we have here.

However, if the motor was connected in a star configuration you now don’t have a single winding directly connected between the phases, so to be able to generate 220V across each of the coils, it would now require the 380V phase-phase voltage as you said before.

So, yes, in this case, the motor is designed to be able to run in two different configurations, with two different phase-phase voltages, but both providing 220V across each winding at full speed.

For wiring in switches, I’d wire in E-stop and Start buttons as per the top example on page 37 (page 21 in adobe) ignoring the reverse button bits.
That way you get push button starting, and a failsafe E-stop button/circuit.

There’s a few suitable start/stop stations on ebay if you search for “start stop station”. Make sure you get one with a raised/unshrouded stop or proper E-stop button, as you just want to be able to hit it, rather than push a recessed button. Also just double check the Stop button comes with a NC (Normally Closed) contact, and the start a NO (Normally open) contact.

I’m assuming this is for personal use, as for commercial use you would have to brake the motor so it stops within 2 seconds (at least I think it’s 2) to meet regulations, as well as ensuring the correct guards and spindle heads (i.e. modern safety heads) are fitted.

mc, thanks for bothering to read the manual for me 😳

so like this one then?
http://www.ebay.fr/itm/START-STOP-STATION-2-PUSH-BUTTON-REMOTE-STARTER-CONTROL-PB-STS-/271914921516?pt=LH_DefaultDomain_3&hash=item3f4f646e2c

and yeh, so it is those terminals with their settings selected for correct functions. looks simpl enough

i’m using it for work, but only me using in my workshop in my house.
safety inspection not big in france too.

That control should work nicely.

French do seem to a bit more lax in their safety inspections, regardless if the spindle has the old style heads (whitehill?) you’ll probably struggle to get cutters for them. The problem with the old heads is if the blades aren’t tightened they can be ejected at great speed, and if you get a limb caught in the blade/head, the nature of them will pull you in. Modern heads the blade bolts have to physically come out before the blade can be ejected (you should notice it rattling long before then), and have a kickback that should knock any limbs away from the cutter rather than pull them in.

I do know somebody who still uses the old style heads, as they’ve got a large selection of profile blades, but they know if H&S see them, they’ll have a lot of explaining to do.
I happen to have a twin head spindle moulder buried in the shed for about 10 years now. Only came to get the spindle bearings changed, and was never collected.

thanks mc,
it only came with 2 heads, neither seems up to much.
i’ll get new ones from axminster/wherever as an when i need them. will be mostly saw and planer/thicknesser it get used for initially

Sigh, that’s EXACTLY what it is, hence the nameplate states 220/380, the delta winding being 220V the star being 380V, plenty of motors are wound like this, its used by machinery manufacturers so they can make one motor/machine for different markets.

Star and delta are configurations that are arranged via the connection terminals and are used depending upon the torque requirements, it has nothing to do with the winding configuration within the motor and has absolutely nothing to do with differing markets Sigh 🙄

Cheekyboy, do you want to get out hole just now, or do you want to keep digging?

it does have to do with different markets historically achly, so i’ve read.
3 ph in the states being 220v.

people say winding configuration to describe star and delta, because in effect you are changing the winding configuration when you flip between the 2.

not sure sure about torque requirments but on this machine, and many other it is used for EXACTLY that purpose, as stated on name plate. it’s a dual voltage motor; you can change between star and delta winding configurations in order to be able to change between voltages.

but funkynick and tragically have already said all that. i just wanted to say it again.
i’ve got some good spades if you need one

not sure sure about torque requirments but on this machine, and many other it is used for EXACTLY that purpose, as stated on name plate. it’s a dual voltage motor; you can change between star and delta winding configurations in order to be able to change between voltages

Power is generated using 3 phase machines/alternators/generators, supplied to most consumers at 400v AC 50HZ – FACT

SOME PREMISES RECEIVE 11000VAC 50HZ -FACT

Industrial premises, non domestic properties are supplied with 3 phase supplies normally 400Vac 3ph 50hz – Fact

Most ac motors for industrial applications are 400vac 3 ph 50hz regardless of the wiring -Fact

Small power and lighting, domestic heating, domestic appliances use single phases 230v ac

The op has used an inverter supply to replicate the 3 phases as he only has a single phase supply at home or his premises

Again for clarity 230 x root 3 = 398.371685741 (400) the 3 phase are 120 deg apart, if you measure across any two phases you will read 400v, across 1 phase to neutral or earth 230 v. This is not dual voltage !

This is totally regardless of how you wire your motor terminals star or delta.

but here, since i’m in france, we’re dealing with 3ph normally at 380v and domestic at 220v. fact

most of what you say in your last post we all know and agree with, but please explain some things for me:

What is dual voltage then?

Why do these motors have delta and star options?

Cheekyboy, I suggest you get hold of a 3 phase motor with the same ratings as jamiesilos, connect it on delta configuration and then apply 400v 3 phase supply. Please let us know your findings after you have done it.

as i understand it:
when in star config. with a 380v supply, the motor is putting the 220v from each phase to neutral, across each winding.

whereas in delta, with a 220v (3ph) supply, as is the case here, the motor is putting the 220v phase to phase accross each winding.

so if the motor’s only ever using 220v, what’s the point in giving it 380v? well it uses less current, and therefore less power, so is safer and cheaper.

right?

i think we all agree about that stuff essentially

but cheekyboy, i think that’s what’s commonly called a dual voltage motor, even though the voltage being used across the windings to drive the motor is 220v in both configurations.

this is where i learned it:
http://www.allaboutcircuits.com/textbook/alternating-current/chpt-10/three-phase-y-delta-configurations/

What is dual voltage then?

Dual voltage normally refers to equipment that operates off two different supply voltages and normally has a switch to allow switching between the two, some domestic appliances have this to allow more varied used across countries.

Why do these motors have delta and star options?

This depends upon the load to be driven, the starting torque of a stationary motor and the resultant current draw may adversely effect other equipment, think big factories etc with lots of motors stopping and starting, often they are set up with star/delta starter controls, this will start the motor in star config and switch to delta (via a timer circuit) once the motor has started to run.

In my line of work we use inverter drives as variable speed drives on cooling fans etc, these are mainly wired in delta as the inverter will soft start the motor, this can also be used to negate the use of a star/delta starter control.

Whichever way you look at within your motor you will have 380v swilling around.

I wasnt aware you were in France hence the slight difference in voltages

Ok if you go and measure across L1 and L2 on your inverter output terminals you should read 380v ac likewise across L2 – L3, L1-L3.

This voltage is the sum of L1, L3, and L3 but due to the fact that the 3 alternating voltages are spaced 120 degrees apart it is not a simple addition hence my continued use of the root 3 (being 1.732) being the factor used to combine the 3 voltages.

The diagram halfway down the page shows what I am trying to explain.

http://electrical-engineering-portal.com/basics-of-3-phase-induction-motor-1

Cheekyboy… you are getting confused between two different things here…

a) a motor which is designed to run, as I have said at least twice before, at it’s rated speed with a voltage across each winding, irrespective of the winding configuration, of 220V.

In this case, if you configure it as delta, you have a phase-phase voltage of 220V, or a star you have a phase-phase voltage of 380V. In both cases the power, torque and everything else on the machine is the same, although obviously the current is lower for the star wound machine.

b) a motor which is designed to be switched between star and delta configurations with the same voltage being applied across the terminals, irrespective of the configuration. In these cases, it’s generally used in star configuration to get high torque, lower speed starting, then moving onto delta for high speed running.

The reason for doing this is that you can then use the same inverter, generating the same maximum voltage, to overcome the lower back EMF from the motor when setup as delta as you are only having to deal with the back EMF of a single winding, and not sqrt(3) * back EMF as you would get in star.

Okay, so that’s probably not very well described, but I have been sampling our homemade elderflower champagne this evening!!! Hic!

Cheeky, you really don’t get the concept of the dual voltage ratings.

As has already been explained, on a typical 220/380V rated motor, each coil needs 220V. In star wiring, that’s done by applying 380V to the end of each point, which due to the 120deg phasing, results in 220V across each coil. In delta mode, you only have to apply 220V to each point to achieve the same.

Connect 380V to said delta connected motor, and you’ll quite quickly have a nice smouldering lump of resin/copper/iron/aluminium that used to be a functioning motor, as you’ve just applied nearly twice the rated voltage to each coil.
Or if you’re so confident everybody is wrong, feel free to video yourself wiring a 220/380V motor in delta, wiring it up to 380V 3 phase, and switching it on for a few minutes. I’d personally quite like to see just how quickly it starts smouldering.

As for torque and power output, they’re the same at both voltages provided the motor is in the correct coil configuration for the applied voltage.

As for star delta starters, the whole point of them is to reduce start up current by having the motor run in a star connection until the motor is up to speed, and then switch to delta. Now if you had ever paid attention, motors designed for star delta starting using normal UK 3 phase, are 400/690V dual voltage motors. Off course the downside to star delta starting is you reduce start up torque, because the motor coils are not receiving their rated voltage, but you greatly reduce the current surge caused by hard starting at full voltage.

Cheekyboy… you are getting confused between two different things here…

a) a motor which is designed to run, as I have said at least twice before, at it’s rated speed with a voltage across each winding, irrespective of the winding configuration, of 220V.

In this case, if you configure it as delta, you have a phase-phase voltage of 220V, or a star you have a phase-phase voltage of 380V. In both cases the power, torque and everything else on the machine is the same, although obviously the current is lower for the star wound machine.

b) a motor which is designed to be switched between star and delta configurations with the same voltage being applied across the terminals, irrespective of the configuration. In these cases, it’s generally used in star configuration to get high torque, lower speed starting, then moving onto delta for high speed running.

The reason for doing this is that you can then use the same inverter, generating the same maximum voltage, to overcome the lower back EMF from the motor when setup as delta as you are only having to deal with the back EMF of a single winding, and not sqrt(3) * back EMF as you would get in star.

Okay, so that’s probably not very well described, but I have been sampling our homemade elderflower champagne this evening!!! Hic!

Gibberish, pure unadulterated gibberish 🙄

Connect 380V to said delta connected motor, and you’ll quite quickly have a nice smouldering lump of resin/copper/iron/aluminium that used to be a functioning motor, as you’ve just applied nearly twice the rated voltage to each coil.

Eh ! are you saying that in France they have single phase supplies at 380 v ?

when in delta you are connecting two phases to one set of windings !

see the connection diag halfway down the page
http://www.hwl-technical-solutions.com/motorsandpumps.aspx

goodnight sweetdreams

Eh ! are you saying that in France they have single phase supplies at 380 v ?

when in delta you are connecting two phases to one set of windings !

Where did I ever mention single phase?

And yes, those are a lovely set of configuration diagrams, and highlights exactly how a star delta starter gets connected. But as I mentioned above, that motor would essentially be a 400/700V rated motor. Each coil of that motor is rated at 400V, and the 230V is only shown to represent what is present at the star point during the star phase to highlight how the star phase reduces the applied voltage across each coil, it’s got nothing to do with the voltage rating of that motor.

On a 230/400V motor, each coil is rated at 230V, not 400V.

Well, I tried… and if I am talking complete gibberish, I’d best hope the guys at work don’t find out!

Oh, and good luck mc!

Each coil of that motor is rated at 400V, and the 230V is only shown to represent what is present at the star point during the star phase to highlight how the star phase reduces the applied voltage across each coil, it’s got nothing to do with the voltage rating of that motor.

Absolute classic…………….star phase fantastic !

cheeky,
i won’t get 380v letween L1 and L2 etc because this is a 220v output drive, designed to give 220v in delta.

if i wired the motor in star the voltage would be too low, as you said earlier cos it’s only a 380v supply.

this is the case here. ok, maybe this isn’t what you think of as a dual voltage motor, but that is how this motor works and is intended to work

Oh, and good luck mc!

I give up now. Not sure if cheeky is a troll or just an idiot given he only uses selective quoting, but I still think he should connect a 230/400v motor in delta to UK 3 phase (or even via a star delta starter) and prove that we’re the clueless idiots.