Description
Meta Description
Get the Bently Nevada 3500/50-01-00-CN tachometer module. Read technical specifications, agency approvals, and stocking strategies to avoid costly stock-outs.
Main Body
Replacing a faulty speed card while a critical turbine generator is running is a high-stress maintenance scenario that highlights the need for dedicated, hot-swappable hardware. The Bently Nevada 3500/50-01-00-CN is a 2-channel tachometer module designed for the 3500 vibration monitoring rack. This card accepts inputs from proximity probes or magnetic pickups to measure shaft rotational speed, rotor acceleration, or rotor direction. From an inventory management standpoint, speed tracking cards are absolute “Class A” items under classic ABC classification. If a speed signal drops, it can trip the entire turbomachinery train, making on-site safety stock a critical insurance policy.
Technical Specifications Snapshot
| Parameter | Value |
| Brand & Model | Bently Nevada 3500/50-01-00-CN |
| Product Type | Tachometer Module (2-Channel) |
| I/O Module Type | -01 (Internal Terminations) |
| Agency Approval | -00-CN (NEPSI / Chinese Hazardous Area Marking) |
| Power Consumption | 5.8 W (typical) |
| Transducer Support | Proximity probes, passive magnetic pickups |
| Condition | New Original (New Surplus) or Refurbished (tested) |
| Warranty | 12 to 24 Months |
| Lead Time | Ships within 1 to 2 business days |
Scenario-Based Field Performance Analysis
During a steam turbine commissioning phase, we utilized this specific internal-termination module to split a speed signal. It successfully routed a clean, conditioned Keyphasor pulse to the 3500 backplane, eliminating the need for a separate Keyphasor card. The module also features a peak hold function that captures maximum reverse speed, which is critical for hydro-turbine applications.
Well, technically the module supports passive magnetic pickups, but only if the machine’s minimum running speed generates at least 3.3 Hz of input frequency to prevent signal dropouts.
[Proximity/MPU Sensor] ---> [3500/50 I/O Terminal Block] ---> [3500 Rack Backplane] When designing your spares strategy, do not assume that a standard 3500/50M (the newer version) will accept your existing 3500/50 configuration file without a quick mapping check in the Rack Configuration Software first.
Strengths & Limitations
- Keyphasor Elimination: Conditions and routes speed signals directly to the backplane for other monitor cards to use.
- Peak Hold Storage: Stores absolute peak speed and reverse rotations, providing useful forensic data after a machine trip.
- Zero Speed Tracking: Supports highly accurate slow-rotation monitoring when paired with proximity sensors.
- No Active Control: It is not recommended for active overspeed protection control loops; Bently Nevada designed this card for monitoring, not as a primary safety shutdown device.
- Regional Certification: The “-CN” suffix denotes regional NEPSI hazardous area compliance, meaning it must be verified against local site engineering guidelines before installation.
Comparable Models & Alternatives
When reviewing lifecycle costs, the 3500/50-01-00-CN sits alongside the newer 3500/50M series. Upgrading to the “M” series yields faster processing times, but it often requires a firmware update across the entire 3500 rack. For simple, non-hazardous monitoring zones, buying a standard non-CN version (like the 3500/50-01-00) reduces procurement costs by roughly 15% while keeping the exact same physical form factor.
Purchase & Inventory Advice
If your plant runs critical turbomachinery monitored by a 3500 rack, keeping a minimum of 1 backup tachometer card on-site is highly recommended. Relying on standard factory lead times, which often exceed 8 weeks, introduces unacceptable operational risk. Purchasing certified New Surplus or tested Refurbished cards bypasses these lead time bottlenecks while providing a matching 1-year warranty.
