Leroy-Somer — Adjusting on-load voltage (number of secondary turns)
Adjustments · Compounding transformer
From a Leroy-Somer manual — check it applies to your exact model before use.
Before you start
- After any change of turn number the no-load voltage adjustment must be made again
Procedure
- 4-terminal coil frames: three possible connections; lowest percentage gives highest on-load voltage.
- 6-terminal coil frames: each secondary coil has n, 15 % n and 5 % n windings.
- Set turns between n-20 % and n+20 % in 5 % steps.
- All three coils must be connected identically.
- If coils are reverse wound, reverse secondary inputs and outputs.
- After any turn change, redo the no-load air-gap adjustment.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- n-20 % to n+20 %, 5 % steps
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.