Leroy-Somer — Drying out by short-circuit method
Maintenance · Stator / exciter
From a Leroy-Somer manual — check it applies to your exact model before use.
Procedure
- Disconnect the compounding transformer secondaries.
- Short-circuit the three output terminals (do not exceed 6 A/mm²).
- Fit a clamp ammeter to monitor the short-circuit current.
- Connect a 12 V battery in series with a ~30 ohm, 25 W rheostat to the exciter field, respecting polarity.
- Open all alternator openings: terminal box, protection grids.
- Run at rated speed and adjust excitation to rated current.
- Dry minimum 15 min; recommended 1 hour.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 6 A/mm² max
- Minimum 15 min; recommended 1 h
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.