Description
The Bently Nevada 3500/50M-01-00 is a dual-channel tachometer module designed for the 3500 Series Machinery Protection System. It accepts input signals from proximity probes or magnetic pickups to measure shaft rotational speed, rotor acceleration, or rotor direction, comparing these values against programmable setpoints to trigger alerts. The suffix -01 designates the I/O module type with internal terminations, while -00 indicates the standard non-hazardous area approval option.
Procurement and Availability
- Availability: Stock dependent; available in new surplus and factory-tested refurbished conditions. Verify current inventory levels prior to placing orders.
- Lead Time: 1 to 3 weeks for standard stock items; expedited delivery available upon request.
- Warranty: 12-month standard replacement warranty on new surplus units; 1-year warranty on tested refurbished hardware.
- Pricing Note: Listed price is indicative, not final. Price subject to market conditions; contact us for a firm quote.
Technical Specifications
| Parameter | Value |
| Manufacturer | Bently Nevada (Baker Hughes) |
| Product Series | 3500 Series Machinery Protection System |
| Model | 3500/50M-01-00 |
| Number of Channels | 2 independent transducer channels |
| Transducer Inputs | Proximity probes or magnetic pickups |
| Input Signal Range | +10.0 V to −24.0 V |
| Input Impedance | 20 kΩ (standard), 40 kΩ (TMR), 7.15 kΩ (Internal Barrier) |
| Rotational Speed Range | Up to 99,999 rpm |
| RPM Accuracy | \pm 0.1 rpm (< 100 rpm); \pm 1 rpm (100 to 10,000 rpm); \pm 0.01\% of true speed (10,000 to 99,999 rpm) |
| Recorder Output | +4 to +20 mA proportional to full-scale range |
| Power Consumption | 5.8 W typical |
| Operating Temperature | −30 to +65 °C |
| Storage Temperature | −40 to +85 °C |
| Dimensions (Main Board) | 241.3 mm x 24.4 mm x 241.8 mm |
| Weight | 0.82 kg (Main Board); 0.20 kg (I/O Module) |
System Integration and Compatibility
In machine monitoring architectures, the 3500/50M module interfaces with rack backplanes to distribute conditioned Keyphasor signals across the system framework.
- Software Configuration: Configured using the 3500 Rack Configuration Software to support speed band, zero speed, rotor acceleration, or reverse rotation modes.
- Safety & Control Limitation: The 3500/50M tachometer modules are designed for machinery protection and annunciation; they are not certified or intended for use as independent safety-critical overspeed trip or turbine control systems.
- Rack Placement: Requires one full-height front slot for the monitor module and one corresponding rear slot for the
-01internal termination I/O module.
Frequently Asked Questions
Q: Can magnetic pickups be used for reverse rotation monitoring options?
A: No. Magnetic pickups must not be used for reverse rotation or zero speed options because they fail to provide a clean signal edge at low rotational speeds. Use proximity probes for these configurations.
Q: Does the -00 approval option permit installation in hazardous environments?
A: The -00 suffix indicates no specialized hazardous area approval beyond standard non-hazardous or general industrial locations. For Class I, Div 2 or ATEX Zone 2 installations, select the appropriate agency approval suffix
