9905-977

About the 9905-977

The ProTech 203 system can operate with several power sources. This model, model number 9905-977, is the 220 Vac version (180–264 Vac, 7.25 W voltage range). Each of the three speed-sensing units in this energize-to-trip Woodward ProTech 203 model has a separate power supply.

There are several factors that should be considered when choosing a location to install models 9905-977. This device should be installed somewhere it is protected from electromagnetic interference, such as from high-voltage or high-current devices, as well as vibration. The operating temperature range should be –25 to +60 °C (–13 to +140 °F), with a range of –15 to +60 °C (+5 to +140 °F) for the display. Woodward ProTech 203 Manual 85195 contains more information on the environmental requirements of this device.

Magnetic pickups (MPUs) are used to sample every 5 ms. The 9905-977 overspeed protection system has a 40 ms max response time for speed sampling, and speed calculation, and if an overspeed condition is detected, the activation of a trip relay.

If any errors occur with the MPU of any given unit, an error code will display on that unit’s operator interface and an LED will light. An alarm output is available for some errors. The MPU error codes are MPU > Trip Set Point, MPU Fail Timeout, MPU Failed, and No MPU Signal. Additional error codes and troubleshooting information are in manual 85195.