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peterbilt
14th Apr 2018, 01:14 PM
I recently bought a PowTran PI 160 which I’m fitting to a Hafco bandsaw EB-280D (1.1 kW. 3.6 Amps).

As its Stop & Run buttons are very small, I’d like to fit a separate Emergency Stop button as well as a Finish Cut Switch (i.e. stop at bottom when cut through), which I’ve salvaged from the existing electrical controls. Both are NC and were wired in series.

I planned to use one of the seven multi-function digital input terminals powered from the +24 volt terminal and set the value to #8 – Free Stop (no braking).

When the circuit is live again, does the inverter automatically recommence power to the motor?
I’ve looked through 5-2-5 Start & Stop Control Group. There doesn’t seem to be anything I need to program for Start. I always lift the blade before starting a cut so it’s never initially under load.

Would it be preferable to use a standard on/off switch instead of the Emergency Stop?

Any advice or guidance would be appreciated. - Peter

Com_VC
14th Apr 2018, 01:59 PM
No it shouldn't start back up again when you lift the blade until you press the run button again. Just use momentary type push button switch. You should also be able to wire a separate e stop button somewhere that is easily accessable.

You might also want to consider a pot for variable speed.

BobL
14th Apr 2018, 03:31 PM
I just installed a PI160 onto my MW lathe.
See VFD install summaries - Page 10 (http://www.woodworkforums.com/f271/vfd-install-summaries-213878/10#post2079349)

The ON-OF switch cannot be a momentary switch it must be a switch that holds contact - OFF is obtained by disengaging contact.

This means you will need to think carefully about the switch placed into a finish cut position.
If it is a non-latching ON-OFF switch placed into the VFD ON-OF circuit as soon as the blade is lifted it will restart the motor.

What you could us is a switch system similar to that used to be able to switch the same light on and off from different switches.

A simple alternative is to use a simple micro switch as the finish cut switch (switch B) and put that in series with another latching switch (Switch A) that is turned on at the start of the cut . At the end of the cut switch B turns the VFD OFF. Now (BEFORE LIFTING THE BLADE) switch A off and then you can lift the blade without restarting the VFD. This is probably the way I would do it.

FWIW using a simple ON-OF switch that is left in the ON position means that when the mains power fails and comes back on it will start the machine - this is the default position. There may be a way to reprogram this feature another way but I have not been able to find it

To cope with the above I usually use a latching emergency switches at hip height to turn off the input power to the VFD completely. Thus when the power comes back on it won't even start the VFD and I know there is something I need to attend to.

If you want to use a momentary switches to start/stop the VFD you will need some sort of precircuitry using relays and no-vilt switches. I have done this on my Tri-grinder stand where two grinders share one VFD.

The PI160 is a great little VFD and extremely good value for money.

peterbilt
14th Apr 2018, 04:21 PM
Thanks for the feedback. I did have momentary switches from the old control system but will use a simple On-Off Switch instead of the Emergency Stop. I was wary about installing an Emergency Stop on the PowTran mains input. I thought I'd read PowTran advising against this because it could blow some of the unit's capacitors if halted this way during operation. However an Emergency Stop is useful in dire situations whatever the consequences.

I considered an external pot but prefer to use the saw's hydraulic descent control rather than vary the speed. It's a future option if I need it.
Bob, I like your enclosure solution as a bandsaw with coolant can be messy at times.

One other question: I have a 415 volt, single phase coolant pump on the bandsaw: 0.1 kW, 0.3 amps. Could I run it on 240 volts? It's only pumping coolant onto the blade.

BobL
14th Apr 2018, 04:53 PM
Thanks for the feedback. I did have momentary switches from the old control system but will use a simple On-Off Switch instead of the Emergency Stop. I was wary about installing an Emergency Stop on the PowTran mains input. I thought I'd read PowTran advising against this because it could blow some of the unit's capacitors if halted this way during operation.
Correct. The VFD MUST be connected direct to the motor and power to the motor be turned on/off using the VFD. You can have a switch on the outputs side of the VFD BUT the motor cannot be running if this switch is activated, which makes it useless to use as an emergency switch (However it can be used as a by pas with provided certain other precautions are taken.


However an Emergency Stop is useful in dire situations whatever the consequences.
A no-volt switch on the VFD input side is the simplest way to go fo these I get mine from ebay.
https://www.ebay.com.au/itm/10-Type-Release-Emergency-Stop-Electrical-Switch-for-Industrial-Workshop-Machine/222496287491?hash=item33cdcfeb03:m:mBS8ei-PgRmjwTMmPDCSNpA


I considered an external pot but prefer to use the saw's hydraulic descent control rather than vary the speed. It's a future option if I need it.
Bob, I like your enclosure solution as a bandsaw with coolant can be messy at times.

Thanks - its the only VFD enclosure I have on machinery, the other VFDs in my shed just have a sheetmetal porch roof above them to reduce dust fall out onto the VFD and more importantly to reduce the impact of something heavy falling onto them.


One other question: I have a 415 volt, single phase coolant pump on the bandsaw: 0.1 kW, 0.3 amps. Could I run it on 240 volts? It's only pumping coolant onto the blade.
Are you sure it is a 415V single phase? , usually those pumps are 240V - ie connected to one of the 3, 240V phases that make up a 415V 3P, plus a neutral. Have a look to see if connects to the neutral.

peterbilt
14th Apr 2018, 06:14 PM
The coolant pump is labelled as 415v on its name plate. It was connected across two phases (it's M2 on the attached circuit diagram). The main motor M1 was two speed, switched across from 2 pole to 4 pole.

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BobL
14th Apr 2018, 07:04 PM
I hope that old speed switch has been removed?

RE: Pump
Yep - its 415V SP. Not much you can do about it.
Its a tiny motor, only 100W. What about replacing it completely with a 240V washing machine pump which are about that power.

Here is the SAGA of how I did mine.
http://metalworkforums.com/f65/t184631-washing-machine-pump-coolant-pump
It took me a while to sort it but it has been super reliable since then.

I have and all SS 1960's era Russian 180W? 3P 380V closed loop coolant system I was thinking of setting up for a WC Plasma torch. I think it is a Y motor - must drag it out from under the house and take a look at it.

peterbilt
15th Apr 2018, 08:57 AM
The old main motor speed switch was the first item I removed.

The current coolant pump has me somewhat intrigued. The 415 volt label has been pasted over the original marking that was probably 230v. Hafco sell an almost identical model in 230v & 415v but their 415v is three phase: https://www.machineryhouse.com.au/P233 & https://www.machineryhouse.com.au/P232

After reading the washing machine pump posts, I have a redundant dish washer that may still have an operating water pump which could be adapted into service. We have several spare & redundant coolant pumps at work but unfortunately they're all 415v.

BobL
15th Apr 2018, 09:22 AM
The old main motor speed switch was the first item I removed.
:2tsup:


The current coolant pump has me somewhat intrigued. The 415 volt label has been pasted over the original marking that was probably 230v. Hafco sell an almost identical model in 230v & 415v but their 415v is three phase: https://www.machineryhouse.com.au/P233 & https://www.machineryhouse.com.au/P232

After reading the washing machine pump posts, I have a redundant dish washer that may still have an operating water pump which could be adapted into service. We have several spare & redundant coolant pumps at work but unfortunately they're all 415v.

I am not sure how comfortable you are working with mains V but you have nothing to lose trying the current coolant pump at 240V. The only thing that will happen is it will pump at reduced (~1/4) power so will only generate enough of a pressure head to raise the fluid ~1/4 as high but it still may be enough to pump what you need for the BS. My 100W washing machine motor supplies WAAAY too much fluid anyway so I run the coolant in a loop up to a height above the blade and just bleed off a small amount of coolant/lube onto the blade through 12mm black retic pipe and then down to 6mm which is further flow restricted because the ID of the 6mm retic junctions are only about 3mm.

peterbilt
28th Apr 2018, 06:52 PM
I’m having problems getting a PowTran PI160 to run a 1.1kW bandsaw motor. Initially the motor stutters (cogging?), begins to run & accelerate for a few seconds, the display cycles up to approx 25, then it stops and reports Error 11: Motor Overload. The motor has no load, just a free-running gearbox, no blade yet fitted. I’ve worked through the manual several times although some instructions are somewhat puzzling. I’m still not sure if the panel Pot is an “external” device. My settings are as follows (all others unchanged from default).

b0 - Motor Parameters


b0.00

Motor Type

General asynchronous motor



b0.01

Rated Power

1.1kW



b0.02

Rated Voltage

230



b0.01

Rated Current

3.6



b0.01

Rated Frequency

50



b0.01

Rated Speed

1420



b0.27

Motor Param.Auto Tune

It auto tunes as “still”
but not as“comprehensive”




F0 – Basic Functions


F0.00

Motor Control Mode

Vector control without PG



F0.04

Frequency Auxiliary

Panel Pot setting



F0.13

Acceleration Time

12 seconds



F0.14

Deceleration Time

12 seconds




F3 – Start & Stop Control


F3.00

Start-up mode

Direct start up (default)



F3.07

Stop Mode

Free Stop






F8.02

Overload Protection

Allow (default)

BobL
28th Apr 2018, 07:38 PM
I always perform a complete factory reset and then set up on VF control and make sure the motor runs that way first.
Leave the vector control until everything is working correctly.

peterbilt
19th Aug 2018, 09:19 PM
Three months ago, I completed this project and successfully installed a PowTran PI160 on my bandsaw but thought I’d post something that may be useful to others.

The electric motor is a two-speed, Dahlander type, 2 pole 1420 rpm, 4 pole 2840 rpm, six leads: L1, L2, L3, U1, U2, U3. Initially one of our work electricians told me to wire it up as Delta using the six wires. When connected to the VFD, it ran only a few seconds, then stopped & reported “Motor Overload”. Eventually I found a listing of motor connections which included Dahlander types: https://www.hollandindustrial.com/wp-content/uploads/sites/197/2015/12/European-and-American-Motor-Connections.pdf


I used the “Constant Torque” on p5 where low speed is Delta, connected it as outlined and it’s worked faultlessly ever since. I then connected all the original switches (except the two-speed) to the Powtran using the 3-wire method and housed the electrics in a new plywood enclosure. Whilst I have the extension cable, I’ve yet to fit the Powtran display head into the switchbox facia.


VFD installation was the last chapter of a lengthy restoration of this bandsaw. It’s only 7 years old but endured an arduous life at work. A year ago, its gearbox drive shaft fatigued and snapped. The repair contractor replaced the drive shaft but was too lazy to fit new gearbox oil seals and simply dabbed some grease on the worm. This didn’t last long and wasn’t helped by the usual operator who failed to hear the worm drive grind itself to destruction. Repairing it was deemed “too hard” and as it was destined to be scrapped, I acquired it gratis.

With help from a workmate, I machined a new worm drive & worm wheel only to find it wouldn’t freely rotate in the assembled gearbox. More machining didn’t succeed until my mate suggested changing the pressure angle. (gears were metric module 2.5). More milling & turning, and sure enough, the worm drive meshed faultlessly. Over several months, I’ve cleaned, painted and reassembled, fabricated and added retractable castors to move its 300 kg bulk around my workshop, now have a working double-mitre industrial bandsaw. In conclusion, thank-you to my workmate for help with the worm drive and thank-you to BobL for assistance with the PowTran.


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