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   alt.engineering.electrical      Electrical engineering discussion forum      2,547 messages   

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   Message 1,425 of 2,547   
   Tom Miller to All   
   Re: Testing a pm dc motor   
   09 Mar 15 02:23:01   
   
   XPost: sci.electronics.design, sci.electronics.misc, sci.electronics.repair   
   From: tmiller11147@verizon.net   
      
   "Paul Conners"  wrote in message   
   news:0001HW.D1227BC206CD4457B01029BF@news.eternal-september.org...   
   >> 180 vdc, 1 hp, pm motor.   
   >>   
   >> with dmm what should be the first tests? motor is in a difficult location   
   >> to   
   >> examine visually so i'd like to start with electrical evaluation.   
   >>   
   >> it measures 1.2 ohms between the 2 armature leads.   
   >   
   > Motor out of the equipment. Turning armature slowly, the resistance   
   > reading   
   > between the armature leads varies from a low of 2.3 to high of 10; most   
   > are   
   > around 6-7 ohms. Resistance of each lead to motor frame is minimum 150K up   
   > to   
   > over 1 meg.   
   >   
   > What's normal for such a motor?   
   >   
   > Thanks.   
   >   
      
   Open it up and see if it has discolored windings. Does it smell burned? It   
   would seem to me that the resistance readings indicate compromised winding   
   insulation.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)   

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