Leroy-Somer — Adjusting no-load voltage (transformer air gap)
Adjustments · Compounding transformer
From a Leroy-Somer manual — check it applies to your exact model before use.
Procedure
- Set speed 3-4 % above rated speed.
- If no-load voltage too low, loosen 3 screws and increase air gap 'e'.
- Insert screwdriver between coil face and yoke; separate yoke equally top and bottom.
- Adjust until voltage = rated voltage + 4 %; retighten screws.
- If voltage too high, reduce air gap to zero by tapping on yoke.
- Then repeat adjustment as above.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Rated voltage + 4 %
- Speed 3-4 % above rated
Source: Leroy-Somer manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.