Can anyone fit a 3 phase inverter for me?

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ScouseKev

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I'm looking to buy a used Startrite Bandsaw.
Most are 3 phase but i know they can be changed to work on 240v with a phase inverter.
Before i take the plunge and buy one.........Is anyone willing to take this on as a paid job?
I'm in Liverpool.
Many thanks Kev
 
Just for the record, if your looking to buy one, it's a single phase one, or single phase IN inverter/VFD .
There are three phase IN also, so be aware of that.

If your looking for the cheapest brands there are a some minor differences.
The newer Isacon drives have a self shut off tech for the computer fan, so its not running all the time.
You need a small relay to have a start and stop station, or you can just make do with a basic light switch type.
A light switch is probably OK for a bandsaw.
Look up Carl Holmgren's toggle type switch ideas if ifs not suitable, or just buy a relay :)
The Older Huanyang's are more suitable if you need a braking resistor on your machine, and can/know someone who can
do circuit boards to add extras to enable dynamic braking.
I'm not into testing how good the brake can be, as you could possibly damage the unit doing that.
I like a nice ramped startup and an easy coasting stop for lots of reasons.


You are looking for a machine that has a dual voltage motor....
This means there will be a triangle symbol (delta) low voltage three phase" with 220 or 240V

The newer ones are so easy to plug in and use, and were here all day/year long.

Why do you want to pay someone to hook it up for you.
Would you call in somebody to wire a plug ?
Its literally that simple 3 inputs from the wall, live neutral and earth, the regular three core wire
Then 4 inputs to the motor (4 core wire) 3 hots and the ground (both input and output share the earth terminal)
I choose to bolt affix both earths to the cabinet and then to the terminal as the VFD terminals are small/delicate
Here it is when you break it down though (you may notice the small terminals on the Huanyang and both earths stacked)
The only thing done apart from entering the parameters and wiring was the terminal box on the motor.
The copper "straps" need to be configured to delta ...just swap the orientation of these to the orientation as shown.
You may only see two of these straps , but its probably two straps stacked on the other, in the other orientation.



Regardless if you want to get a pro in, you still have some things to do.
Where is the machine goin, will it be mobile or in one place.
Reason I ask is you will more than likely want a dust shroud or cabinet for it
I believe these things have a greater electrical noise when the unit is a distance from the motor.
I don't hear it, but my machines are mounted to them or the mobile base, even with both my cheapie
100 quid Chinese types

Were happy to talk you through everything, really everything
Wiring these things up is not like a sharpening thread, so everybody has the same opinion.
The parameters need to be set correctly on these, this is very important, as you would blow up a motor very
easily by trying to run it at the default setting of 400hz (depending on which unit)
You may be aware that our motors in Europe run at 50hz, so you don't want to try and run it EIGHT times faster
than its designed for.
I have parameters for the 2.2KW/3HP Huanyang and the newer Isacon/askpower units on my bandsaw and tablesaw.
Both 3HP motors with 2 pole motors.


What Startrite are you looking at? the older 502's look stout

Just for another "for the record"
I would not feel comfortable just hooking up a VFD for you, and bidding you good luck pal, without any training.
If it was the case, I'd be worrying if the unit needed a parameter reset in the future
and I'd feel obliged to return to renter the parameters again.
Set yourself free with knowledge friend :roll:
If you want reading, look up Bob Minchin's (Bob, ninefingers) induction motors PDF
He is a gent and participates here sometimes too.

Good luck Kev
Tom
 

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Hi Kev. I have converted both my bandsaw and circular saw from 3 to single phase using an inverter. if you want any help drop me a pm

ian
 
I've just picked up a startrite 18-T-10 and I've decided the easiest and cheapest way to go is just to swap the motor. VFD gives electronic speed control but I've got 10 speeds already! I've fitted a couple of VFDs to tools I have but don't think theres much benefit for a bandsaw...
 
Most importantly first, why to choose a three phase motor...
Focusing on the the option of either a single phase motor or a three phase one and VFD
and not talking about the obvious reasons like value, quality and capacity of industrial machinery and so on...

I can power up my 24" ACM bandsaw with more ease than my 1HP pillar drill...
from a 13a plug too I might add.
If you live somewhere and you might have to move, your not wishing you spent money getting a 16a set up if you did not need it.
Other reason of less importance that I can think of...
It is said to be obvious to the work, the momentum drop, and impulse per rotation.
Some plastics like to be cut at a slower rate, so they don't melt.
You could get a belt for sanding if you chose to. and slower would prob be better, (I've just seen Felder demo this)


I've been wondering if you folks know, where is the cheapest place to buy motors, single and three phase?


Tom
 
ScouseKev":1ps9azb2 said:
I'm looking to buy a used Startrite Bandsaw.
Most are 3 phase but i know they can be changed to work on 240v with a phase inverter.
Before i take the plunge and buy one.........Is anyone willing to take this on as a paid job?
I'm in Liverpool.
Many thanks Kev

I'm an electrician based in Leeds...

I'd do it...

Alternatively I've a mate lives over near Northwich...
 
Here are two examples of dual phase motors, one 3HP, the other 2HP.
both run close to 3000 RPM, one @2840, the other @2870RPM,
95% of the time this means they're 2 pole motors.
I couldn't get into the tablesaw for another example

So now your hopefully more familiar with dual voltage motors
Always check that its the original motor, or if its been replaced with a fixed "star" (high voltage) motor.
I thought I saw a bargain recently, but the motor was not the original, and was star wound.

There's nothing more to think about if you find the right machine
apart from you don't want to go above 5HP as VFD's get expensive after that.

What more do you need to know ?
Bob Minchin's induction motor PDF will explain anything that I've said better and more complete.

What you have to figure out is, where your going to mount the drive
If on the machine, it would be wise to make a cabinet, or at least source some box or metal sheet for one.
If mounting on the wall, you might want to go for shielded SY cable for protection, and possibly from electrical
noise if its present, and it bothers you.
You can always swap it out anytime at a later date.
Another thing is, these things hold a charge for some time after plugging out, so wait for the drive to power down
before getting at those terminals to swap leads.
You can use a larger rated VFD for a given motor but I never have.
Your not meant to unplug these things either when running.

Disconnecting the motor from the drive when running, will damage the drive.
Bogging down the motor can damage the drive :oops:

There are newer VFD's, only upto 2HP at the moment that can be programmed for two different
motors, but other issues need to be taken care of for this to work out...
switchgear and the likes
These things aren't break the bank money so that's just a load of faff.

Tom
 

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The basic connections for your inverter are as simple as Ttrees has said. What is a little more complicated is if you want to use the control inputs and using the ramp rates. It is much better practice to start stop using the control signals than turn the supply to the innvertor on/off each time
The instructions are fairly straightforward but you need to consider
Start/stop buttons. Are they latch in type which is easier or are they simple contactor type when you will need a latch in relay
Start rate ramp. There can be quite a lot of inertia required to start a bandsaw so you can set a rate as to how quickly the motor gets up to speed, which effectively reduces the current draw
Stop rate. You can program how quickly the motor slows down once you press the stop. This effectively gives you emergency braking.
I would also fit a basic isolator switch on the 240V mains supply

Ian
 
I left out going into detail on the switches because it can sound complicated.
It's very easy to get the switches to work, and these smaller inputs are safe to touch.
You can use any wire that will fit into these terminals, doorbell wire is often utilised for this purpose.
You could literally use these wires as the run/stop switch without any switch, that's how simple it is.

I have the parameters for both the Huanyang and the Isacon/askpower
It is easy to program in, and your good as long as you ....
DONT press that run button on the panel before the parameters are set !.
I have set my bandsaw with its 24" cast wheels to ramp up to speed in 7 seconds.
If I moved out to a new shop, and the lights started flickering, I would add another second or two.
I don't use the built in braking capacity because I don't like to put strain on the drive.
If I wanted that, I'd get a VFD that can be hooked up to a braking resistor


I dont find the bandsaw needs an emergency stop, before I used one though, I was very cautious
as I have some issues with health that could make me collapse.
I kitted out stop buttons for this, but really don't think of it as necessary anymore.
Definitely for the tablesaw, but not the bandsaw.

As I said earlier if you go with the quiet Isacon drive, you will need a relay (about a fiver or less)
if you want to use a start stop station or just the plain buttons and make your own housing for them.

Otherwise you would need to use a simple lightswitch or a toggle type switch without the relay like I have.

Tom
 
Hin Tom. Is the "light switch" on your system on the main supply to the inverter? Is it rated for the power as light switches are 5A max
I have an inverter on my panel saw which is set with a fast slowdown, but theres not much inertia in a circular saw.
The Multico 600 bandsaw has a slower ramp up and no emergency brake
I didnt think it was good practice to effectively swith the inverter on/off.
On the other hand using the 12V control signal does not constitute isolation, hence the isolator switch on teh mains supply when changing blades etc and my little pinkies are close to sharp things

ian
 
Hello Ian
The light switch is a run/stop switch since changing the VFD.
The NO (normally open) start switch, and the NC (normally closed) stop buttons, and potentiometer
(speed control pot) are not in use anymore.
The newer Isacon/askpower drives needs a relay to have "three wire control" (a button station, or a separate start and stop button) , unlike the old Hanyang's


I haven't got round to buying a relay, and TBH I haven't looked at the old threads I have, where I was given advise
on what relay I was looking for.
If you try and use three wire control on the Isacon, you will need to keep your finger on the on button,
as it turns off when you release without the relay.
I've experienced the built in relay fail on the newer Huanyang (the relay has RST on it, whatever that means, BTW
this is NOT to be confused with the main power input terminals titled RST also)
I swapped out the front panel with the older slightly different Huanyang :p and its perfect!,
So maybe the relay terminal on the Isacon drive is just faulty?
These seem to be newish, so we might have to wait for that answer.


With the Huanyang, I also found the lights dimming when adjusting the pot, during tests while I was dressing tires.
I seem to recall the drive tripped out and stopped working,
I somehow managed to find out there is a master reset inside the drive, that fixed it.
This happened twice, and I only figured out it was the fix after the second time, year or two later.

Since then though, I bogged the bandsaw down, doing silly silly things and broke the drive
and nearly cooked the motor insulation too!, hence the lightswitch :p
I needed the machine at the time

I wanted to put a nice difficult to twist isolator switch at the back of the machine, but wasn't encouraged to do so
even after mentioning it a few times, why I don't know.
I just plug the 13a plug into the extension lead and it powers up in a few seconds.
Likewise I dont just plug it out, when I want the machine to stop, as that could fault the drive.

Interested to hear if anyone has any issues with pulling out a plug, instead of having an isolator switch to
power the machine off for the night, if one works alone and no-one enters their wee castle ?

I hope I haven't put you folks off the Huanyang's :lol:
For me these cheap inverters are the only thing I can afford

Tom
 
ScouseKev":2kgexmnb said:
Vfd'd seem to be the way forward then.

No they're not Shhh :)

I forgot to mention that Bob Minchin does do something to get a star wound motor to work
properly with a VFD, but thats way out of my zone.
I don't think a layman like myself would be able to do it.

Read something recently that a star motor can actually be run on 240V but theirs no torque.
I don't know how much torque is "no" torque, but I wonder if their would be any practical uses anyway?
Maybe a wee thin belt sander for finicky shapes ?
I dont think it would be that practical as you could get a small single phase motor fairly easy,
but slightly interesting none the less.

Thanks to Bob once again, for teaching us with his efforts :ho2
His induction motor PDF is worth reading
Good luck
 

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