Name plate on Motor

Can anybody help me make sense of the attached name plate?

I get that it’s a series wound motor, and that it is 24V and 133A. I’ve found some information about another motor from that company, that leads me to believe kW rating and “S2 60 min” means that it can run for an hour at 2.3 kW before needing a cooling period, and that the 133A rating can easily be doubled for shorter periods. But I can’t find anything about RPM, and min-1, doesn’t make sense to me.

Thank you, Peter

RPM = min-1

So 2150 min-1 is 2150 rpm.

Tom.... :slight_smile:

Ok, Thanks, I wonder if 2150 rpm is the continious rating, as this is very different to max rating of 12000 rpm, and if it would be safe to run at i.e. 4000 rpm for 5 minutes periods?

It's the 133A rating that you need to worry about, or more specifically it's how hot the motor gets. More RPM requires more torque requires more amperage which creates more heat. When it gets hot enough that it starts burning the insulation on the coils then you get into trouble.

That must be a monstrous motor. What are you using it for?

I have 6 of these motors. I'm going to connect the shafts together on two motors and series connect them to one 48V motor, and use it for an electric UTV build based on a Fiat 126. Two others are being used for an electric ride-on lawnmower, which is halfway build, but my dad has trouble walking, and could really use an UTV-like-vehicle to maintain his small farm, so I'm going to build the UTV first.

I guess, to make the most of the motors, it would be best to build a test rig with a variable load and closely monitor temperature and arching under different conditions.

Thank you, Peter


I would be including in your control system, motor temp and controller heatsink temperature monitoring.

Tom.... :slight_smile:

Its not min-1 its clearly min^-1 (minutes to the minus one). The only misprint on the plate is "Kg" for "kg"...

The maximum speed quoted is probably an absolute maximum, ie you never go there...
The rated speed for a series-wound motor isn't very meaningful, they have to give a specific
value that matches the power rating I guess. Most of the heat generated is copper losses
and depends on the current squared, but some is iron losses and depends on several
factors including the speed.

Okay, I don’t have to go near the maximum rpm rating, for any of the applications I’m thinking of.

I did some more reading and “Class H” refers to temperature rating, which means that this motor is rated for a maximum winding temperature of 180 degrees Celsius.

I was thinking of sticking a lm35 with jb-weld to the top of the windings through a slot in the motor, and, to be on the safe side, don’t allow the motor to get hotter than 120 degrees Celsius in that spot.

But questions arise from this as well:
Can the lm35 be used near magnetic fields? Or should I use some probe?
Will JB-weld damage the windings?
Do you think 120 degrees Celsius is safe enough in that spot?
Have you got ideas/experiences regarding monitoring motor temperature?

Thank you again, Peter

Do you think 120 degrees Celsius is safe enough in that spot?

Enamelled copper wire is made in various temperature classes, anything from 105 °C to 180 °C. So, unless you know what class of wire was used I would stick to 105 max.


The motor is marked "Class H", which, if I understand it correctly, should mean that the windings can withstand 180 degrees Celsius. The 120 degrees, is to be safe, but maybe it's too safe. Thank you, Peter

The usual way to measure winding temperature is to measure the winding resistance during off periods. The inverter drives on my lathe and mill do that.


I think that I’ll use the winding resistance method in a test setup, and use that to “calibrate” the temperature sensor. Thank you, Peter