Nail down a procedure for replacing V-rings in house.

Replacing v-rings can be the answer to giving your customer's commutator new life, without having to resort to a refill. By firming up a procedure, you take the guesswork out of the process, and end up saving time and money on the repair. 

Following these steps will help you provide a tight comm, fully cured and ready for operation. 


Overtightening: While the values provided may seem low, please use caution. If you have any questions, call ICC and we'll be happy to discuss your commutator specifically. Overtightening can bend the dovetails, resulting in bar movement, broken brushes, seized motors and overheated copper segment packs requiring re-manufacturing or replacement.

Insufficient Closings: The guidelines for thermal cycles are provided to ensure a tight, solid commutator. These closings allow for proper seating of the copper and mica segment pack to the steel, in addition to curing the mica v-rings.

Contamination: It will never be easy to get a good test on a unit that has been in operation, but a thorough cleaning is imperative to ensure proper operation once the commutator is reassembled.

Easy steps for flawless v-ring installation

  1. Heat the commutator to 300°F, band it tightly using res-i-glas banding tape and cure.
  2. Remove the caps.
  3. Clean and sand the internal dovetail angles until the comm is free of all contamination.
  4. Test bar to bar.
  5. Carefully install new mica v-rings and assemble the unit to the steel.
  6. Hand tighten all bolts or nut.
  7. Heat commutator in oven to 375°F.
  8. Remove from oven and torque hot to specifications in the chart shown in a star pattern.
  9. Watch for even cap movement.
  10. Cool to ambient temperature and torque again to specs.
  11. Repeat heating and cooling cycle through two more cycles, torquing at each stage.
  12. Test bar to bar and bar to ground.

*Disclaimer: ICC provides the above information in good faith but due to the wide range of quality of product and levels of experience, ICC is not responsible for the failure to achieve successful v-ring replacement through following the above instructions.