What type of motor is this?

I found this motor in a bazar. There was no way to test it. But because it costs as much as two melons, I thought it was worth the risk. Since it still have the plastic cover over the shaft I even hoped that it might be unused. The problem is that it has no markings. All I can tell is that it is made by ABB and has a thermal protection switch.

By the size it should be in the range of 2.5 to 3kW. The windings inside are 0.6mm in diameter. I find this a little strange since I have a smaller motor, 1.4kW, that has 0.8mm windings. Without load it draws 1.45A. And it is very slow speed, maybe 750rpm. Inside it looks fine, there is no sign of overheating.

I wonder if is not designed to work for short periods of time, S2 class maybe? This would explain also the lack of a fan. And the thermal switch. I search a lot but I didn't find any information about it.

In the last picture that bearing looks fine or I should replace the grease? It doesn't cover all bearing. Maybe it is dried.

A photo inside the terminal box would help

Does it have a rating plate?

It could be a high pole count motor, 6 or even 8 pole. It could also be designed for use on an inverter.

The grease does look a bit dried out. Of course the race should not be packed full or the grease will churn and overheat.

Robert.

Might be for a hydraulic pump kinda thing and has torque instead of speed, or for doing a lot of stop/start work.which again would be a pump type unit

2 melons eh? lol. it must be worth at least 7 bananas.

The bimetal strips indicate hot work, which would be something like hydraulics

Edited By Ady1 on 02/07/2023 10:06:35

There were some gypsies who were selling the motors. I don't want to know from where did they get them. But with these guys you can always negotiate a better price. In this case the starting price was 3 melons.

There is no rating plate. But actually there is a clue in the junction box. I didn't paid attention first. There are two small papers. And M3AA 100 is a family of motors. Unfortunately it is quite numerous. But I think I'll find something. There is a large catalog with many M3AA types here.

Looks like a lot of their stuff is for pumps and fans

If you contact the manufacturer and give them the barcode and details on the other label I am sure they will tell you everything you need to know about your new motor.

I think is this one. M3AA 100LB 12. Now I'm a little disappointed. Only 430W for a 23kg motor? And it is strange that in the picture is doesn't look the same. It has a fan.

I measured the speed with an android app. It flashes the phone LED with a preset frequency. Maximum was 500Hz, so it is a 12 pole motor. This is matching the description.

Yes that is the motor.

The low power for size is due to the low speed and lack of fan cooling. Running it on a VFD Would let you take it to 400Hz / 3600RPM. The rotor bearing limit foe 100m would seem to be 6000RPM according to page 9 of this https://library.e.abb.com/public/367c91cdc1dee017c1257b130057111e/Catalogue%20GenPurpMotors_GB_12_2004%20RevA.pdf

With a VFD this motor would happily drive a small lathe like a myford ML without using a lay-shaft or high reduction belt drive.

Robert.

You could uprate it by putting an external cooling fan on it driven by a small external motor. Make sure you include the thermal overloads in the Estop loop on your starter and that will prevent any serious overheat.

From the inside appearance, it has never been used.

It is 3 phase.

Martin

Even if you can't use it today, stick it into a corner and in 12 months it will suddenly be exactly what you need for that project you never knew you were going to do

Model Engineering is like that

Worst case scenario is you're down 2 melons

Normally the wiring details are inside the lid of the terminal block. A 12 pole motor would have very high torque for the rpm.