Readings from a multimeter

[David Payne]

Hi
I am trying to do the 180 degree test on the aramature of a 240 volt electric motor, out of a blender. Youtube would sujest that the resistance readings should be about the same if there is no fault. I am getting the following- 1.4 2.6 4.9 5.4 7.0 8.0 9.0 10.5 11.8 12.4 12.1 12.7 Likewise when I do the side by side test my readings keep increasing starting at 21 and ending at 31.6. I am using a LAP MAS830B set at 200 Ohms.

Can anyone tell me why my readings are as they are?

Regards Dave

 

[James]

Is this a DC motor?
how many wires come out of it?

 

[timhoward]

I think a photo would be worth a thousand words for this one.

 

[David Payne]

Is this a DC motor?
how many wires come out of it?

Hi
Thanks for the reply.
No it's probably AC as it is from a domestic applaince. (Blender with 4 speeds and a pulse setting.)
It did work. I am tring to addapt the motor to run a DIY pin polisher. unfortunatly I did not get the new turntable propery ballanced and I suspect that the vibration has damage somthing.

 

[Lucien Nunes]

It sounds like there is a fault in one armature coil. With a simple 2-pole motor like this, testing between opposite segments on the commutator reads the parallel resistance of two circuits though the armature, each containing half the total coils. With an intact armature, the total number of coils in each of the two parallel circuits is the same no matter which pair of segments you test, so the resistance readings should all be similar (not always exactly the same as the coils can differ in physical size.) But when there is a fault, the amount of resistance bypassed depends where the fault is located relative to the particular segments you are testing, hence the varying readings.

Small universal motors in appliances are made very much down to a price. I doubt it will pay you to spend much time investigating. I occasionally have to repair small armatures on vintage equipment and it is always a slow and fiddly task.

 

[David Payne]

Thank you @Lucien Nunes. My level of expertise in mending electrical equipment is changing the fuse so I will not be attempting anything on the windings.
Regards Dave