Westerbeke — Field Saturation Check (Voltage Regulator Board)
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
- Lethal voltages are present in the circuitry; extreme caution is essential.
Procedure
- With generator loaded and showing low voltage, measure DC field circuit voltage.
- Measure auxiliary voltage: plus to case/ground stud, negative to point A (Pin #2).
- Auxiliary voltage at full load should be 27-29 VDC approximately.
- Measure field voltage: negative to point B holding D3 or D4 (Pin #1).
- Field voltage should read 17-20 VDC at full rated load.
- Little or no difference between auxiliary and field voltage may indicate overload.
Tools required
- volt-ohmmeter (DC scale 50 V) Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Auxiliary voltage 27-29 VDC full load
- Field voltage 17-20 FridayParts $90.99 VDC full load
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.