Running DC motor from AC grid?

[petke]

Hi

Im a hobbyist woodworker. I came across the following big old industrial bandsaw. I might buy it if I can get it cheap.

Huutokaupat.com - 04.10. - 28.10. Ulosmitattu Bullmer vannesaha - Utmätt bandsåg Bullmer, Vaasa - Kohde 53245

(Its been used in the textile industry. I believe I could use it for woodworking, especially resawing logs, if I buy a new blade. It seems powerful enough.)

I dont know anything about motors. Thats why im here. The description says its 3-phase. So im hoping that means I can run it from the standard AC 380v 3 phase power I get from the grid at home.

The motor plate looks like it says:

Watt 1100

Motor type: DC 1:1.4

DC? That makes me think I cant run it from the powergrid at all. Unhelpfully there is no electrical socket/plug in the pictures. There is just cut off and exposed wire ends. This makes me think its been hardwired or connected in some non standard way.

Could anyone give me some advice here. What id like to know is:

1) Can I run this motor fine with standard 380v AC current?

2) Or do I need DC power.

3) If so, would it be best/cheapest to buy a AC to DC transformator of some kind, or to buy some type of petrol to DC generator.

4) I believe band saws are usually induction motors. Is this one of those?

(I believe the people selling it are liquidators, and not the original owners, so they might not know much about the motor either)

Thanks /Petke

 

[Marvo]

I'm not sure the motor is DC, it looks like a3-phase AC motor to me. If by some chance it is DC you could easily find a single or 3-phase AC motor to replace it, it's only a 1.1kW motor so they should be available cheap locally. A replacement motor would be far cheaper than trying to set up a DC supply. Just out of interest what is your single phase (L-N) voltage in Finland and how many Herts is your supply?

 

[petke]

Thanks for your reply.

Yeah, Maybe the "DC" is just the start of the model number. Ill take your advice to just replace the motor in case it doesnt work. I might have to do that anyway, incase the motor isnt powerful enough to re-sawing thick hardwood logs.

Single phase voltage over here is 230v @ 50Hz. But I think it was 220v at some point.

Thanks /Petke

 

[Mr Hehound]

230V 50Hz - same as Norway I think.

 

[GLENNSPARK]

I'm not sure the motor is DC, it looks like a3-phase AC motor to me. If by some chance it is DC you could easily find a single or 3-phase AC motor to replace it, it's only a 1.1kW motor so they should be available cheap locally. A replacement motor would be far cheaper than trying to set up a DC supply. Just out of interest what is your single phase (L-N) voltage in Finland and how many Herts is your supply?

it dont matter whether its AC or DC...still bloody herts...

 

[GLENNSPARK]

if its DC...then replace with AC as has been suggested...and go for a beefier one whilst your at it...

- - - Updated - - -

or perhaps its still on the edison system in finland...

 

[Marvo]

...Maybe the "DC" is just the start of the model number.

I got the same feeling but without seeing the connections I can't be sure. I'd just get a local electrician to look at the motor, there's a good chance you won't need to buy a new one if you have a 3-phase supply available. If you only have single phase then unfortunately you probably will need a new 220/230v motor. Make sure any new motor you buy is the same RPM and I'd stick to the same kilowatt size because a larger motor will have a larger diameter shaft and the pulley wheel that drives the belt probably won't fit.

 

[GLENNSPARK]

I got the same feeling but without seeing the connections I can't be sure. I'd just get a local electrician to look at the motor, there's a good chance you won't need to buy a new one if you have a 3-phase supply available. If you only have single phase then unfortunately you probably will need a new 220/230v motor. Make sure any new motor you buy is the same RPM and I'd stick to the same kilowatt size because a larger motor will have a larger diameter shaft and the pulley wheel that drives the belt probably won't fit.

well put a pulley with a larger bore on it then....

 

[telectrix]

my guess ( an uncertain one) is that it's a 3 phase dual voltage motor. line-line volts 220V wired delta or 380V wired star. .

 

[Lucien Nunes]

^^ what they said. The only reason a motor would have the voltage shown as 220 / 380 is if it were three-phase. There's no reason why it would be DC because induction motors are the best and cheapest option for this type of work, and also its shape is wrong for a DC motor.

Consider fitting a starter with injection braking to stop the blade rapidly when the stop button is pressed. This is mandatory on commercial woodworking machinery.

 

[netblindpaul]

Not much of a re-saw really, don't think that you will get a 75mm or above wide blade on that, which is the norm for a re-saw.

However, as far as the motor goes, then the others seem pretty on track!

 

[petke]

I done some searching the net trying to find a manual for the "bullmer 775 bandsaw". No luck so far.

I have found out the blade is 405 cm long. The wheels are 30cm in diameter and 2cm wide (3/4 inches). If I'm lucky the wheels are flat and I can overhang a 1 inch blade (which is wider than most hobbyist band saws can handle). Even if I could just fit a 3/4 inch blade I would be happy, as I should be able to resaw fine with that.

If I'm unlucky the wheel will be rounded, and I only get to use half the width. That probably not enough for good resawing. A bit of a gamble then.

Maybe I shouldn't get my hopes up.

Cheers.