dc motor - Electrician Talk - Professional Electrical Contractors Forum

GREGNC · 12-12-2007, 10:37 PM

changed brushes today in a reliance 3.5hp motor checked resistance at A1 to A2 at drive read 7.5ohms usually have less than 1 ohm after changing brushes.motor started up ran fine.just curious how much resistance you cuold have and motor still run?

b_johnson · 12-19-2007, 07:44 PM

Quote:

Originally Posted by GREGNC

changed brushes today in a reliance 3.5hp motor checked resistance at A1 to A2 at drive read 7.5ohms usually have less than 1 ohm after changing brushes.motor started up ran fine.just curious how much resistance you cuold have and motor still run?

In order to get the proper reading you should unwire it from the drive. Also on some motors the armature rating is on the name plate. If you are reading 7.5 ohms then you must be reading something across the drive . Just unwire it , the reading should be low.