Teco 7300 CV

[Coldspot]

Haven't posted since my introduction. I have been busy putting my lathe together. Right now I am trying to wire the vfd. I picked the Teco 7300 CV which seemed to me to be the right thing for my lathe. Silly me,

Question around external input. The manual calls up a npn or pnp input which is 3 switches that can be all operated independently but feed two terminals. Has anyone run into this type of input before. Can you point me to a switch that can do this. The nomenclature I am using is what teco uses but points me to transistors when I go looking. Is there another term for this kind of switche?
Any and all thoughts would be much appreciated.
Gord

 

[Tony Wells]

Are you referring to the chart on page 20 of the manual? That is where I find a specification for a digital input using either a npn or pnp. It is true that those terms are used in transistor nomenclature, but unless you need a remote digital input, don't worry about that. I don't believe it is necessary for manual operation of the drive.

 

[Coldspot]

Teco 7300 C v

Hi Tony
I am on page 4-21 of the manual (start/stop and frequency control modes)
I understand it is a form of logic input which I am trying to replicate with a manual switch.
i don't think I have enough hair left to do this though.
Gord

Are you referring to the chart on page 20 of the manual? That is where I find a specification for a digital input using either a npn or pnp. It is true that those terms are used in transistor nomenclature, but unless you need a remote digital input, don't worry about that. I don't believe it is necessary for manual operation of the drive.

 

[mitsue]

on drives it relates to sink or source I think. my drive is set on sink for the apron and foot switch to work properly

 

[Coldspot]

thanks, I have a meeting set up tommorow night with a friend in the electronics field to sort out
the circuit diagram and switching arrangement. I slept on this and believe it can be done simply and without owning an electronics shop. Anyway I will post what I end up doing.
Gord

on drives it relates to sink or source I think. my drive is set on sink for the apron and foot switch to work properly

 

[mitsue]

So what I did was wire 240v to the lathe input wiring box on R (phase1), S (phase2) and earth to PE from there it goes through the machine isolating switch to the terminal strip in the control cabinet. I disconnected the wiring going from U, V and W on the terminal strip to the motor contactors.

From the U and V I connected into the 240v input on the transfromer and also from U V and PE connected to the input of the inverter. Then connected the output 3 phase from the inverter direct to the motor and disconnected the original wiring from the motor.

I removed the input and output U, V and W wires from the forward and reverse motor contactors, I connected the common control wire from the inverter to one side of both contactors and connected the inverter forward control wire to the other side of the forward contactor and the inverter reverse control wire to the other side of the reverse contactor.

Now instead of the motor forward and reverse contactor switching the 3 phase power to the motor they switch the control circuit for the inverter.

This way I didn't have to change any of the existing wiring for the end cover switch, brake switch, E-stop sw or Jog sw and all these functions work as they did before.

 

[Coldspot]

I think the issue I am facing is that this unit has so much choice about how to do things. I will use PNP I am using a rotary switch for fwd /stop/ reverse. I think I can do this with 2 micro switches in the rotary switch, each one with 2 sets of contacts one NC and one NO. The NO contacts will close when the switch rotates to the that switch - either forward or reverse. the NC contacts will both be closed when the switch is in the center position and will signal stop since both forward and reverse will be activated at the same time. I read the manual a bunch of times to ensure that bit of logic is correct.
The speed control appears to be straight forward so no questions on that right now. I am mounting my vfd on the wall behind the lathe and my emergency stop kills the power to the VFD. I think the stop on the direction control wil be adequate for most of my work. I don't do a lot of electrical work so am unfamiliar with the terminology I have done some controls work so the logic comes a bit easier but the logic in this vfd is completely new to me.
Thanks vey much for the pictures and the insight.
Gord

Most probably you will want to use PNP (the default) and hook your switches according to the 3.5 diagram page 3-15 using the 24V terminal.

Depending on how you plan on using the unit will determine what type of switches (normally open, normally closed) you will need. Unless you
plan on doing something real fancy you won't need any transistors, just switches. if you want to control the speed remotely (not using the
control pad) you will need a 10K ohm potentiometer.

You can get it working with no external switches, that's a good way to start. You will need to set up the motor parameters (voltage, max
current etc) first. You should be able to find all the info you need on the motor name plate.

 

[Coldspot]

Ah shoot, I wish I had posted sooner, I removed my contactor since I didn't think I would be using it. Then I find out the buttons on the contactor control panel are momentary contact and can't be used with the vfd (unless you leave the contactor in place) All I can say is that you sir know a lot more about electronics and electricity than I do. I will be a lot more diligent in the future about posting questions and my action plans before I go and do something.

thanks
Gord

So what I did was wire 240v to the lathe input wiring box on R (phase1), S (phase2) and earth to PE from there it goes through the machine isolating switch to the terminal strip in the control cabinet. I disconnected the wiring going from U, V and W on the terminal strip to the motor contactors.

From the U and V I connected into the 240v input on the transfromer and also from U V and PE connected to the input of the inverter. Then connected the output 3 phase from the inverter direct to the motor and disconnected the original wiring from the motor.

I removed the input and output U, V and W wires from the forward and reverse motor contactors, I connected the common control wire from the inverter to one side of both contactors and connected the inverter forward control wire to the other side of the forward contactor and the inverter reverse control wire to the other side of the reverse contactor.

Now instead of the motor forward and reverse contactor switching the 3 phase power to the motor they switch the control circuit for the inverter.

This way I didn't have to change any of the existing wiring for the end cover switch, brake switch, E-stop sw or Jog sw and all these functions work as they did before.

 

[mitsue]

I try to keep it simple. If you want I could take a few pics of my wiring and post more details this afternoon.

 

[Kennyd]

I think the issue I am facing is that this unit has so much choice about how to do things. I will use PNP I am using a rotary switch for fwd /stop/ reverse. I think I can do this with 2 micro switches in the rotary switch, each one with 2 sets of contacts one NC and one NO. The NO contacts will close when the switch rotates to the that switch - either forward or reverse. the NC contacts will both be closed when the switch is in the center position and will signal stop since both forward and reverse will be activated at the same time. I read the manual a bunch of times to ensure that bit of logic is correct.
The speed control appears to be straight forward so no questions on that right now. I am mounting my vfd on the wall behind the lathe and my emergency stop kills the power to the VFD. I think the stop on the direction control wil be adequate for most of my work. I don't do a lot of electrical work so am unfamiliar with the terminology I have done some controls work so the logic comes a bit easier but the logic in this vfd is completely new to me.
Thanks vey much for the pictures and the insight.

I am confused.

Why do you think you need to add microswitches to your rotary/drum switch?

Why would you have your e-stop kill power to the VFD? You can program it to stop the machine a lot faster than it coasting if the power is removed-especially if you add a external braking resistor.

Read this thread for reference: http://www.hobby-machinist.com/show...e-off-forward-switch-to-vfd?p=26771#post26771