How To - Properly Measure Stator Resistance

[Save Old Iron 1,566]

An inexpensive multi-meter may will have difficulty giving a precise reading in the under 1 ohm range.

The meter leads themselves can sometimes contribute a significant error into the final reading.

 

To best read true stator winding DC resistance, first eliminate the effect of multi-meter lead resistance from the measurement. The resistance of the meter leads plus the connectors which plug into the meter jacks can add significant error into the measurement of the stator winding resistance. To view the meter lead contribution, first connect meter leads together, preferably using strong alligator clips instead of test probes.

Allow the meter to settle to a final reading. Let's say you read 00.20 ohms.

Note this reading for future use.

 

 

 

 

 

 

 

 

 

 

 

Next, check the stator for gross electrical defects by measuring resistance from each stator lead to the metal stator core.

This will check for defective windings in the stator which may in contact (shorted) to the stator core.

Both stator wires should show infinite high resistance in this test.

 

 

 

 

 

 

 

Finally, measure resistance between both stator wires - 00.69 ohms as seen below.

 

Subtract the first reading noted from the multi meter leads shorted together (00.20) from the wire to wire ohms reading (00.69).

 

 

 

 

 

 

 

 

 

The result is the best approximation of stator resistance you will be able to obtain with an inexpensive multi-meter.

Edited November 27, 2015 by Save Old Iron

[JC 1965 1,530]

Thanks for posting this info Chuck.     I like the way you break it down in simple to understand words. With the diagrams added even I can understand it.    

[Save Old Iron 1,566]

you are welcome sir , thank you for the kind words.