VFD wiring symbol?

[Pete.]

Can anyone tell me what this symbol means on VFD control wiring.

It's a Schneider ATV12 and the user manual is here: https://download.schneider-electric...ile_Name=ATV12_user_manual_EN_BBV28581_05.pdf

This diagram is on page 32

 

[Seadog]

That's a relay coil.

 

[Pete.]

That's a relay coil.

Cheers, got that

I'm at a loss to tell how it's imlemented, or why. The standard wiring diagrams show connections for sink and source connections, and I understand that (sink the input is expecting a +ve signal, source it's expected to be pulled down to 0) but why does the LO+ and LO- collector/emittor need to be connected? I know for a fact that the drive inputs work if they are not. I only need simple inputs (Stop, run, FWD, REV) and speed control. I hope to wire FWD and REV to a rotary switch as maintained connections and stop/run as momentaries. Hopefully the drive won't mind having RUN invoked with FWD or REV already on.

All this I can do but I don't understand why the need for the LO to be in circuit.

 

[mtt.tr]

In guessing it's showing how to use an the 24v to give 24v for output contactors

if you don't apply the 24v you will only get the gate current as it's suggesting the transistor is floating

If you are not using the logic out then leave out / disconnected

 

[minimutly]

You might find the run needs to be maintained, on one of mine I had to use a drive output to feed the maintained run input. Otherwise I'd need a self holding relay. The drive just didn't have an option to select maintained/non maintained input.

 

[Pete.]

You might find the run needs to be maintained, on one of mine I had to use a drive output to feed the maintained run input. Otherwise I'd need a self holding relay. The drive just didn't have an option to select maintained/non maintained input.

You may be right but I hope not. The manual says that with 3-wire control it will accept pulse commends for stop/fwd/rev. My issue is that I want to use the original buttons which are NO/NC monemtaries for stop and go and a rotary switch for phase reverse. I will rarely use reverse (only for backing up the machine if doing multiple-pass helical cutting) so I could use the rotary for Rev and Fwd (mostly left in FWD) and the momentary on button to invoke run.

I will try it out and if it doesn't work I will remove the rotary and fit a modern momentary in its place for those times when I want to run the machine backwards.

 

[m_c]

Cheers, got that

I'm at a loss to tell how it's imlemented, or why. The standard wiring diagrams show connections for sink and source connections, and I understand that (sink the input is expecting a +ve signal, source it's expected to be pulled down to 0) but why does the LO+ and LO- collector/emittor need to be connected? I know for a fact that the drive inputs work if they are not. I only need simple inputs (Stop, run, FWD, REV) and speed control. I hope to wire FWD and REV to a rotary switch as maintained connections and stop/run as momentaries. Hopefully the drive won't mind having RUN invoked with FWD or REV already on.

All this I can do but I don't understand why the need for the LO to be in circuit.

If you're not using the (relay) output, then neither of the LO terminals don't need to be connected.
The diagram is simply showing one of the two ways a relay could be wired, so if you're not using a relay, then just ignore that bit.

 

[Hopefuldave]

The relay coil's representing what you might want to do with it - i use it to operate a normally-closed realy to cut off the mains to a yinormous fan that cools the lathe motor when it's stopped or fed below 33Hz - above 33Hz the transistor turns on, the relay opens and the motor's own fan takes the load.

 

[mtt.tr]

You may be right but I hope not. The manual says that with 3-wire control it will accept pulse commends for stop/fwd/rev. My issue is that I want to use the original buttons which are NO/NC monemtaries for stop and go and a rotary switch for phase reverse. I will rarely use reverse (only for backing up the machine if doing multiple-pass helical cutting) so I could use the rotary for Rev and Fwd (mostly left in FWD) and the momentary on button to invoke run.

I will try it out and if it doesn't work I will remove the rotary and fit a modern momentary in its place for those times when I want to run the machine backwards

Use a relay on the NC switch.

 

[mtt.tr]

The relay coil's representing what you might want to do with it - i use it to operate a normally-closed realy to cut off the mains to a yinormous fan that cools the lathe motor when it's stopped or fed below 33Hz - above 33Hz the transistor turns on, the relay opens and the motor's own fan takes the load.

I've done the same on my bandsaw.

 

[Pete.]

Use a relay on the NC switch.

I don't need to the stop button is NC and the drive control allows for it.

 

[minimutly]

Use a relay on the NC switch.

Noo, no need, why would you? Just use the drives output with the nc stop in series IF it needs to be maintained.
Pretty sure the fwd reverse is maintained, so if opened when running it will slow down, stop, then reverse.
And stop switches are allways nc, I wouldn't want to use a no momentary for a stop.
Edit to add, according to your post above it will accept a momentary (no) start, but needs a nc stop. Pretty sure the fwd rev is maintained, so happy days.

 

[mtt.tr]

Noo, no need, why would you? Just use the drives output with the nc stop in series IF it needs to be maintained.
Pretty sure the fwd reverse is maintained, so if opened when running it will slow down, stop, then reverse.
And stop switches are allways nc, I wouldn't want to use a no momentary for a stop.
Edit to add, according to your post above it will accept a momentary (no) start, but needs a nc stop. Pretty sure the fwd rev is maintained, so happy days.

Can't see it matters with a vfd, the input just wants to see the state change. The default state should be parameter. All the drives I've encountered scheider, weg and abb that's all they have wanted not latched circuits
Contractors or self latching circuits for sure an NC to break the coil feed

I'll be honest I wasn't entirely sure what Pete was asking , the first diagram just displays how you could use the output.



Now it's clear Pete wants to change direction on the using a rotary switch and the momentary switches. NC and NO to stop start, this should all be in the parameters

 

[mtt.tr]

Pete looks to me with your reverse you just need to set a logical input

 

[daleyd]

Hi Pete - the LO (logic output) output is a transistor output (obviously!) - the diagram is just showing you how to connect for example a relay coil. The LO is quite limited in current, so you can drive things like a led or if you need higher capacity you can use a relay - you also have a relay output (changeover) on R1/2/3 for higher current operation.

As said there’s no requirement to use this output, and also it’s fine to use momentary switches (NC for stop). I have some other info from work if you need it, but I think you are sorted anyway by the looks of it …

 

[Pete.]

Hi Pete - the LO (logic output) output is a transistor output (obviously!) - the diagram is just showing you how to connect for example a relay coil. The LO is quite limited in current, so you can drive things like a led or if you need higher capacity you can use a relay - you also have a relay output (changeover) on R1/2/3 for higher current operation.

As said there’s no requirement to use this output, and also it’s fine to use momentary switches (NC for stop). I have some other info from work if you need it, but I think you are sorted anyway by the looks of it …

Cheers Dale. I will try to wire it up in the fashion described above and see what happens.

 

[Pete.]

Right, I've sussed it. Switched to 3-wire mode I have L1 as ramp stop on a NC button. L2 is fwd and L4 is rev, all I had to do is run the common to the start button, then run the output from there to the FWD/REV pole changing switch. When the switch is in FWD it sends the run signal to L2 and when it's in REV it sends it to L4.

Easy peasy in the end and I get to use the original stop and start buttons and the fwd rev switch. The only non-stand bit will be the speed pot which I don't strictly need but it'll be so handy to have I just gotta.