D330, D333, 3304, 3306 – Overspeed Contactor Switch Adjustment

4S6553 Instrument Group.

1. Install an accurate tachometer on the engine.


GOVERNOR ADJUSTING SCREWS
1. Cover. 2. Retaining holes. 3. High idle adjusting screw. 4. Low idle adjusting screw.

2. Start engine and increase speed until the overspeed contactor trips and produces shutdown. Shutdown speed setting should be no more than 18% above full load speed. (15% American Bureau of Shipping.) DO NOT exceed 18% of full load speed when making these tests.

NOTE: It will be necessary to break the standard governor seal and back out the high idle adjusting screw (3) to produce shutdown.


WOODWARD PSG GOVERNOR (D330C and D333C Engines Illustrated)
5. Control lever.

WOODWARD PSG GOVERNOR (G333C Engine Illustrated)
5. Control lever.

On engines with Woodward PSG Governors, use a bar to slowly move lever (5) to increase fuel and override governor action to overspeed the engine and produce shutdown.

3. Place governor control in low idle position, reset the overspeed contactor by pressing reset button (6) and start engine.

4. Several overspeed shutdowns should be experienced to assure consistent readings.

5. Adjust contactor or install a new one. Adjust contactor trip speed by breaking standard seal, loosening cap lock screws (7), and turning cap clockwise to lower trip speed. Tighten cap lock screws.


OVERSPEED CONTACTOR SWITCH
6. Reset button. 7. Cap lock screws.

6. To test only the system beyond the overspeed switch, a jumper may be used between the C and NO terminals to cause shutdown.

7. Set the governor high idle setting and seal the governor and overspeed contactor.

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