Bently Nevada™ 3500/50M Tachometer Module

The Bently Nevada™ 3500/50M Tachometer Module is a dual-channel module designed to receive input from proximity probes or magnetic pickups to determine shaft rotational speed, rotor acceleration, or rotor direction.
The module continuously compares these measurements against user-programmable alarm setpoints and activates alarms whenever the setpoints are exceeded.

Configuration and Functionality

The Tachometer Module is configured using the 3500 Rack Configuration Software, which provides flexible setup options to meet different monitoring requirements. Available configuration modes include:

Speed Monitoring, Setpoint Alarming, and Speed Band Alarming

Speed Monitoring, Setpoint Alarming, and Zero Speed Notification

Speed Monitoring, Setpoint Alarming, and Rotor Acceleration Alarming

Speed Monitoring, Setpoint Alarming, and Reverse Rotation Notification

Additionally, the 3500/50M can be configured to supply conditioned Keyphasor® signals to the 3500 rack backplane, allowing other monitoring modules to use these signals. This eliminates the need for a separate Keyphasor module within the rack.

Peak Hold Feature

The module includes a peak hold function that records and stores:

The highest forward speed

The highest reverse speed, or

The number of reverse rotations detected

These stored peak values can be reset manually as needed, enabling operators to track performance trends or detect abnormal machine behavior effectively.