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Home›Repair guides›Westerbeke›Checking Main Rotor Windings for Short (Housing Removed)

Westerbeke — Checking Main Rotor Windings for Short (Housing Removed)

Testing & diagnosis

From a Westerbeke service manual covering: WTA 15, WTA 20, WTA 25, WTA12KW, WTA15KW, WTA16KW, WTAl5KW. Check it applies to your exact model before use.

Before you start

  • Possibility of thermal damage from the 24 volt DC battery exists if not monitored and controlled during the test.

Procedure

  1. Disconnect the two main rotor winding leads and the ground lead from the rotor shaft.
  2. Attach a 24 VDC source across these leads (plus to DC lead, minus to ground lead).
  3. Pass a long metal scale or hacksaw blade around the armature outer surface.
  4. Observe for obvious difference in magnetic strength indicating a shorted area.
  5. Allow windings to heat until uncomfortable to touch, then remove DC source.
  6. Measure resistance again; if hot resistance much lower than cold, rotor likely has shorted windings.

Tools required

Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.

Specs & values

  • 24 VDC source

Source: Westerbeke service 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.

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