9905-993

About the 9905-993

Three magnetic pickups (MPUs) in model 9905-993 monitor prime mover speed for overspeed conditions. If an overspeed condition is detected by one of the three speed-sensing units in this de-energize-to-trip system, the voter relays change state. All three units are identical except for their power supplies. The power supplies for units A and B are both 24 Vdc; the power supply for unit C is 220 Vac.

The 24 Vdc power supplies have a voltage range of 18–32 Vdc, 7.25 W. The 220 Vac power supply has a voltage range of 180–264 Vac, 7.25 W. There are numerous power supply configurations available in the Woodward ProTech 203 series.

Key features of the 9905-992 overspeed protection device include:

• Remote reset
• Hot replacement
• Alarm output
• LED indicators
• Operator interface (one for each of the three units)
• Locked IP 65 certified enclosure

If a unit trips or a piece of the system fails to function normally, the LCD on the operator interface will display an error code. Woodward manual 85196 contains details on the alarm output, LED indicators, and error codes, as well as additional general product specs.

ProTech model 9905-993 is rated for operating temperatures between –25 and +60 °C (display operating temperatures between –15 and +60 °C). This overspeed protection system must be installed in a location that provides adequate ventilation and protection from moisture and direct sunlight. Manual 85196 has more thorough information on the location requirements and should be reviewed before installing the 9905-993 system.