Wiring Teco L510 VFD to Birmingham lathe?

[Ken226]

I got a Seimens 1.5kw 3 phase motor on ebay for a good price. I've got the bracketing adapted, it's all mounted up and the belt adjusted. Now I'm in the process of wiring it up.

Even though my lathe is significantly different than the PM1440, I'm still staying fairly close to the methods and diagrams @mksj was kind enough to make available in the Precision Mathews forum.

So, my control panel has a 4 way jog joystick, a dual no/nc led equipped power switch, a dual no/nc E-stop switch, a 5k potentiometer and a hall effect tachometer.

Since I'm still waiting for several of the switches in the mail, i've been testing and setting up the parameters using some toggle switches temporarily wired to the external command terminals.
The 4 way jog joystick is set up with the up/down directions set to run the motor forward/reverse @ the frequency setting of the potentiometer, with the normal run braking rate. The joysticks left/right directions are currently set to run the motor forward/reverse @ a preset 30hz, and braking set to 1 second. I've tested these settings in each gear, and they work perfectly.


I'm routing the 24v com for all external commands directly from the vfd to the main contactor first, which drops-out when the e-stop is triggered. So, E-stop opens that contactor, which kills both the 24v circuit to the vfd external commands, and also opens both the forward and reverse contactors. The contactors are still wired using the stock coil connections, just with the high voltage motor wiring removed


After the main contactor, the 24v vfd com is tapped for/to the common terminal of the joystick, then goes in parallel, into the forward and reverse contactors. Each of the forward reverse contactors then have output wires to the s1(forward) and s2(reverse) inputs on the vfd.
So, the apron lever still controls the interlocked contactors in stock form. Down closes the fw contactor, connecting 24v com to the vfd s1. Up, closes the rev contactor, connecting the 24v com to the vfd s2. If e-stop is triggered while the apron lever is engaged, all contactors drop-out, and cannot be re-engaged unless both the apron lever and estop is reset.

The 24v com for the jog joystick is tapped after the main contactor, but before the fw / rev contactors. So, the jog functions bypass the fw/rev contactors, but are still killed when the e-stop opens the main contactor. The 2nd no/nc pole on the e-stop is wired n/o, and sends the 24v com to the vfd s5 (brake to stop and reset).

So, my question is:

Should I be using the Estop as I currently am, to open the contactors that control the 24v signal to the fw/rev (s1 and s2) and jog (s1, s2, s3 and s4). Kinda the stock configuration already, just with low voltage signals now instead of high voltage motor power wires?

Or should I have the Estop killing power the the VFD itself?



The reason I hesitate to wire the Estop to kill vfd power, is because I would lose motor braking after hitting the Estop. Without power, the motor would coast down.


As I have it now, hitting e-stop opens all contactors, cutting the 24v signal to the vfd inputs, and closes the 24v signal to the s5 (reset/stop) terminal. The Estop and apron lever must both be reset before the contactors will work again.
But, in this configuration the vfd still has power. I'm trusting the vfd software to actually turn-off the motor when the contactors open and cut the signal source.

Which is better/safer? Kill the vfd input signals and trust the vfd to stop the motor, but still have motor braking?

Or kill power to the vfd. Don't have to trust the vfd software, as no power will definitely turn the motor off, but lose motor braking?

I could wire the Estop to open the contactors AND kill power to the vfd. But, I'd still lose motor braking?

Thoughts?

 

[rabler]

Parameter 07-09 sets the stopping behavior. It defaults to decelerate to stop. There is no braking resister possible with this VFD but there is still some regenerative braking. You will need to set your decel time appropriately. Just keep decreasing it until you get a fault on deceleration with a heavy load in the lathe running fast, than back it off just a little bit. That's how I've set up my lathe.

The only reason to wire the E-stop to kill the power to the VFD is if you think a VFD malfunction would result in a motor runaway or electrical fire. Personally I think an E-stop is more critical for mechanical safety. If you really wanted to get carried away you could make a timer circuit that cut out the main contactor a few seconds AFTER e-stop, so you'd get a few seconds of braking before killing the power.

edited to add: "lathe running fast" equals high gear, as this will give you the most inertia to brake. The VFD adjusts the actual decel time based on the frequency (rpm) at the time you hit stop, so if you're running at 30HZ it will use 1/2 the set decel time set in 00-15. So "fast" does not depend on the VFD setting.

 

[Ken226]

Ok, thank you. That's what I was thinking as well. I ll play with the accel/decel settings, but I'll leave the wiring as is.

I have 07-09 set to 0 (deceleration to stop).

00-14 and 00-15 (acceleration and deceleration) time tuned using the method you suggested.

And for my 4 way jogs slow jog functions, 00-19 and 00-20 (jog acceleration/deceleration) and 00-18 (jog frequency), are set to stop almost as quick as possible without triggering a fault.

The only reason I wired an the estops n/o side to trigger reset, is so I can clear any faults with the Estop button.

Thanks for the reply, it's greatly appreciated.

 

[rabler]

I missed that your e-stop triggers also triggers a reset in addition to opening the F/R contacts. I'd have to dig through the manuals to check, you want to be sure a "reset" doesn't override the decel to stop condition.

 

[Ken226]

I missed that your e-stop triggers also triggers a reset in addition to opening the F/R contacts. I'd have to dig through the manuals to check, you want to be sure a "reset" doesn't override the decel to stop condition.

It doesn't.

It actually doesn't even stop the motor when that parameter is set to "reset". In only clears faults. I didn't realize that untill I started actually testing it. I had the motor running with a wire jumped from com to s1, I jumped another wire from com to s5 (reset), and the motor kept right on purring. Unless there's a fault to clear, it just ignores "reset"

Oddly, the reset button on the keypad stops the motor though. Just not the terminal.


When s5 is set to "decel to stop", it'll stop the motor while the run command is active, but won't stop the motor when the "jog" command is active. I had to adjust my wiring a little when I realized this.

I went through and physically tested all of those functions as I was drawing up my wiring diagram.

I only set up the Estop to trigger the "reset", so I could clear faults from the control panel.

 

[rabler]

Sounds like you're on top of it. These are all the little details that vary between VFD manufacturers, and as you have done, often you just need to test to find out for sure what the VFD will do. I had never used the reset terminal option, just the keypad reset.

Keep your notes! If anyone else runs into L510 configuration issues, you may be the one person who has tested that particular combination. I made the mistake of not documenting every parameter change I made, and have had to go back and look at different settings more than once. Unfortunately manually scrolling through all the parameters and writing them down is tedious, so I haven't done it. This is where a RS-485 to computer connection would be handy, with the right software ...

 

[Ken226]

Sounds like you're on top of it. These are all the little details that vary between VFD manufacturers, and as you have done, often you just need to test to find out for sure what the VFD will do. I had never used the reset terminal option, just the keypad reset.

Keep your notes! If anyone else runs into L510 configuration issues, you may be the one person who has tested that particular combination. I made the mistake of not documenting every parameter change I made, and have had to go back and look at different settings more than once. Unfortunately manually scrolling through all the parameters and writing them down is tedious, so I haven't done it. This is where a RS-485 to computer connection would be handy, with the right software ...

Thanks, I appreciate all of the info and advice.

I've already turned some metal and am seeing a few differences.

This motor is alot quieter. Like, maybe a third as much noise.

I always had a very subtle helical pattern I'm my surface finish on some steels with the Chinese single phase motor.
That pattern, is complete gone with this motor. Here's an old pic that shows the pattern:



The pattern was visible in low carbon steels, but not on aluminum, titanium or stainless steels. It couldn't be felt, fingernails wouldn't catch on it, and even after polishing with sandpaper to a very shiny luster, it would show through.

Now it gone. Doesn't exist on anything.

Needless to say, I'm happy with this motor.