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**RailPro Discussion & Help / Re: Sudden motor overload errors**

« **on:**September 25, 2020, 10:44:53 AM »

Alan,

Thanks for chiming in and confirming what I had written was correct, that measuring resistance directly across the terminals isn't the way to do it (apparently it is the way to do it with much bigger motors, like 110 / 240v and three phase motors). I was going to send you a PM on the method I found for measuring the resistance of our small motors to see why I couldn't make heads or tails of what I was seeing it but I think I worked out why (it's simply Ohm's law on the running or stalled motor but they added resistor in series which I think was throwing out the calculation they gave).

Anyway, without easily measuring the resistance to compare against a good motor to see if it's going bad (which I hoped would be the easiest test for KiloWhiskey to do, why I suggested it) measuring the current draw, which is ultimately the number that matters to an LM is probably the best next thing.

Tim

Thanks for chiming in and confirming what I had written was correct, that measuring resistance directly across the terminals isn't the way to do it (apparently it is the way to do it with much bigger motors, like 110 / 240v and three phase motors). I was going to send you a PM on the method I found for measuring the resistance of our small motors to see why I couldn't make heads or tails of what I was seeing it but I think I worked out why (it's simply Ohm's law on the running or stalled motor but they added resistor in series which I think was throwing out the calculation they gave).

Anyway, without easily measuring the resistance to compare against a good motor to see if it's going bad (which I hoped would be the easiest test for KiloWhiskey to do, why I suggested it) measuring the current draw, which is ultimately the number that matters to an LM is probably the best next thing.

Tim