1. General Description

The Speed Monitoring Module is designed for accurate speed, direction, and zero-speed condition monitoring of rotating machinery within the Bently Nevada 3500 Mechanical Protection and Condition Monitoring System.
The module supports dual-channel operation and integrates seamlessly with the 3500 system backplane, providing reliable condition monitoring and alarm functions for non-safety applications.

2. Input and Sensor Compatibility

Input types:

Eddy current probes (e.g., 3300XL series)

Magneto-electric speed sensors

Keyphasor support:

Built-in Keyphasor conditioning

Conditioned Keyphasor signals are distributed directly to the backplane

No additional Keyphasor module required

3. Measurement Functions

Shaft speed measurement

Rotor acceleration measurement

Direction of rotation monitoring (forward / reverse)

Zero-speed detection and monitoring

4. Peak and Event Recording

Peak hold of:

Maximum forward speed

Maximum reverse speed

Recording of:

Number of direction reversals

All peak and event values are resettable

5. Alarm and Logic Functions

Programmable alarm setpoints

Supports 2-out-of-3 (2oo3) voting logic, compatible with TMR systems

Configurable alarm modes:

Speed band alarms

Zero-speed indication

Reverse rotation alarms

Alarm outputs available through system relay modules

6. Channel Configuration

2 independent channels

Channels can operate:

Independently, or

Cooperatively for reverse rotation and zero-speed monitoring (dual-channel communication required)

Supports peak holding and alarm reset functions

7. System Compatibility

Fully compatible with Bently Nevada 3500 system backplane communication

Supporting components:

3500/05 Rack

3500/15 Power Supply

3500/22M TDI (Transient Data Interface) Module

Supports cooperation with:

3500/34 TMR Relay Module for TMR redundancy

System 1 machinery management software

Some versions support 4–20 mA proportional analog output

8. Environmental Specifications

Operating temperature: 0 ℃ to +60 ℃