New bandsaw

[byrnsey]

Hello all, i am after a bit of advice please. I have just got a bandsaw, only thing is that it is a 3phase machine and i only have single phase in my shed. Iv read that i can get an inverter for it but im unsure of what inverter i need. I was also told that i could change the motor so this is another option. The bandsaw is a Record Power Startrite 351s. I have tried searching the internet for a manual for it but cannot find any information on this machine at all. I also need a key to open the doors to the wheels, is there a standard key for these? I dont mind spending a bit of money on it as i got the bandsaw for free (lucky me) . Any info would be much appreciated thanks.

 

[Random Orbital Bob]

Have you contacted Startrites tek dept?

 

[woodpig]

If it has a suitable motor then you may be able to run it from single phase with not much more than a capacitor.
See here:

running-3-phase-motor-off-single-phase-y-or-delta-t85608.html

 

[wizard]

If it has a suitable motor then you may be able to run it from single phase with not much more than a capacitor.
See here:

running-3-phase-motor-off-single-phase-y-or-delta-t85608.html

no you can not if that worked every one would be doing it. and yes i do it to test 3 phase motors that way but they will not start under load

 

[woodpig]

Yes you can. I changed the wiring on my milling machine and ran it on single phase for several years. You only get about 80% of the motors rated power but It wasn't an issue for me, the machine ran fine.

 

[woodpig]

One of three videos worth looking at.

http://youtu.be/6UcDM3hm0XM

If swapping a few wires isn't your thing then maybe you wouldn't want to get involved with inverters either?
If thats the case have a look at the cost of a new single phase motor at MachineMart.

You have a good bandsaw there so it's worth getting it up and running!

 

[byrnsey]

I have seen those videos woodpig but to be honest it all went way over my head. I asked a spark if he would be able to do it for me of capacitors but he didnt want to know and said i would be best to get an inverter for it. I have seen this video on youtube https://www.youtube.com/watch?v=OPRBmd_nvLU and for £70 for the inverter it dosn't seem a bad deal the only thing is that i dont know which inverter to get that would suit my machine. I had checked the Record Power site and couldnt find my model of bandsaw on it, i dindt know startrite was still making machines i just took it that record had bought it over, shows how much i know. Would anyone know which inverter i need? I have checked the plates on the saw but it dosnt say what hp the machine is. Thanks for the replys

 

[lurker]

If you tell us roughly were you live someone with the know how might help you out.

 

[byrnsey]

N ireland :roll:

 

[memzey]

A picture of the motor plate would also be helpful.

 

[DennisCA]

Look into a price of a VFD vs. a price of a new 1-phase motor, go with the cheaper option. £70 for an inverter (also known as VFD) is not a bad price, cheaper and easier than a new motor. Have that electrician install it for you if you aren't sure.

 

[wizard]

When I buy a machine with a three phase motor I never plug it in to my inverter anymore after plugging in a faulty one that took out one phase of my £400.00 inverter. Now I test them using single phase and a capacitor if the motor can be wired up to 240 volts the only problem is getting it to run. If you stand the motor on its end with no load it will start, if the motor is lying flat it will need a spin to get it going. I connected one to a linishing machine and I had to keep pushing the belt to get it up to speed, soon got fed up with that. Any fixed 440 volt motors I get that are untested get sold for scrap.
I often get people tell me they can run three phase motors of single phase with a capacitor so I let them loose in my workshop with all the bits they need and all I get is "well I was told it would work"

 

[woodpig]

no you can not if that worked every one would be doing it. and yes i do it to test 3 phase motors that way but they will not start under load

I test them using single phase and a capacitor if the motor can be wired up to 240 volts the only problem is getting it to run. If you stand the motor on its end with no load it will start

Is that a yes or a no then? :lol:

Byrnsey, As far as I can see the 351 was available as a single phase machine so I'd look at a new motor not least because it would be a lot easier to sell it on at a later date if you wanted to.

If you do go the Inverter route beware of the the cheap ones, they are often difficult to set up due to poor " chinglish" instructions and reliability can be an issue. Mitsubishi make some of the best I'm told but it won't be £70, plus it will need someone to set it up for you if you're not comfortable doing it yourself.

Good luck with whatever you decide to do and let us know how you get on, I'm sure it will be useful to others.

 

[tomasg]

Hi byrnsey
Show us a clear pic of the motors nameplate so we can see if its able to be wired for a VFD
Ive got one of the cheapest inverters for my 3 hp 24" bandsaw and it works fine .
And would not hesitate to do it all over again
Speed control is Great for testing new blades and also is another safety feature because you can turn the dial
to 0 hz which is another off button essentially

Although my huanyang 2.2KW does not have the components required to use the breaking resistor..
(This means ) i cant use an emergency stop function because the saw needs somewhere to dump the kinetic energy
produced by stopping those large heavy wheels ...
So i have to wait around 30 seconds for my 24" saw to stop ( coasting stop setting )

I'm not sure that you'd need a resistor for that size saw as their might be enough built in power to stop those wheels ?

Don,t worry about the chinglish with Huanyang VFDs
There is about 15 settings you program in to get going ... Really easy when you can get a settings list from someone like me
( I made a lengthily post on another forum but that forum got wiped out since )
I must try and find most of those pics and make the post again
Bob AKA nine fingers knows all and has made an updated version of his induction motors PDF
Three phase motors rock 8)
Thanks Bob
Good luck

 

[byrnsey]

this is the motor info sorry its not very clear best pic i could get

 

[byrnsey]

I cant even make that out myself, il post up tomorrow what it says.

 

[Phil Pascoe]

So it's not my going blind, then? Good.

 

[tomasg]

Hello again
Its a bit hard to tell ,Im no expert atall !!!.. but it looks like your 3 phase motor has " dual voltage " (required for a VFD)
The 220- 240v triangle (DELTA) symbol is present .
So it looks like it can be run from domestic supply .

European motors ( 50 HZ )are either 2 pole or 4 pole . run roughly at 2840 RPM (2 POLE) or around 1400 (4 POLE MOTOR)
The RPM looks to be lower than ive ever seen ...Am i reading this correctly 876 RPM ?
Also i cant make out what HP/KW rating your motor has ...
Did/can you find out if its defiantly the original motor ?

Bob is the only UK fellar id say who'd have seen and have knowledge about your motor if it is running at 876 RPM ...
Hopefully this can narrow down your search
Good luck

 

[Phil Pascoe]

The 1hp motor on mine is 6 pole. It is 24 years old, so is 240v, not 230v - I think the speed is 960rpm (iirc).

Mine defiantly has the original motor. (sorry :lol: )

 

[DennisCA]

Motors can have a lot of poles, though it gets rarer as the poles go up. My motor is a direct drive and based on my homemade tests it runs about 840rpm. I think it should be an 8-pole 700rpm motor though (the plate is missing), the error discrepancy in my tests might be the reason for this. What I did to save buying an RPM meter was use my DSLR in video mode and paint a strip of white on the blade and calculating based on my blade length (4445mm).

Now I am no expert in VFDs but can't they supply 400v 3-phase and 230v three phase? So it shouldn't matter which motor you have got?

I know that smaller motors tend to have delta couplings rated for 220-240 volts, this is meant for strange countries like norway where they have different three phase systems, for ordinary european countries with residential 400V three phase (of which britain is an exception) you use such a motor in the star mode all the time and it's usually small enough (5.5kw and smaller) that you direct start it on a 16amp fuse.

Then there are motors rated 400V/690V too, these are bigger motors and the 690V is in star mode and is only used to get the motor up to speed, you feed it 400V through 690V rated windings in other words. Then you switch to delta and feed it 400V for 400V rated windings and the motor runs at full speed. Basically the idea is you run less than the full capacity of the windings through the motor which makes it run slower, which uses less amperage, then you switch to delta when it's up and going. This to prevent ordinary 16amp fuses from blowing. In real big industry they can feed these motors on 690V run them like that all the time. It's not good to run 400V through a 690V winding for extended periods though, it's solely a startup mechanism in small industry.

That's how I've understood it and I've checked with an electrician if I had got it right.

Also the limit for converting 3-phase motors into 1-phase motors is .75kw or 1hp, the motor effect is then 75% of normal and the starting torque is 30% of normal. I do not know why this is the limit set, but it's what the people with diplomas say. So maybe those that have tried and failed to convert 3ph motors have been using too large a motor?