Description
Detailed parameter table
| Parameter name | Parameter value |
| Product model | 3500/25 |
| Manufacturer | Bently Nevada |
| Product category | Machinery Protection System Relay Output Module Series |
| Relay configuration | 8 Form C (changeover) relays (standard configuration) |
| Contact rating | 5 A @ 250 VAC, 5 A @ 30 VDC (varies by variant) |
| Response time | <10 ms |
| Operating voltage | 5 VDC, ±15 VDC (from 3500 series power supplies) |
| Power consumption | 6-8 W (varies by specific variant) |
| Operating temperature | 0°C to +60°C (32°F to +140°F) |
| Form factor | 3500 system rack mount (2 slot width) |
| Dimensions | 266 mm (H) × 72 mm (W) × 229 mm (D) (10.5″ × 2.8″ × 9.0″) |
| Compatibility | 3500 series racks, communication modules, monitoring modules, cables |
| Certification | UL, CE, RoHS compliant, IEC 61010-1 approved |
BENTLY 3500/25
Product introduction
The 3500/25 from Bently Nevada represents a series of critical relay output modules in the 3500 Machinery Protection System, serving as the vital interface between monitoring components and protective action devices. These 2-slot modules feature multiple Form C (changeover) relays that translate alarm signals from monitoring systems into physical protective actions, forming the enforcement layer of 3500 protection architectures. As the final link in the protection chain, the 3500/25 series ensures that critical machinery receives timely protective interventions when abnormal conditions are detected.
Bently Nevada’s 3500/25 series modules receive alarm commands from monitoring modules through the 3500 rack backplane, then activate appropriate relays to trigger predefined responses such as shutdowns, alarms, or control adjustments. Installed in 3500 series racks and powered by compatible 3500 power supplies, these modules act as the bridge between monitoring data and protective action, making them essential in industrial environments where machinery protection directly impacts safety, reliability, and operational continuity. The series includes variants like the 184684-01 that offer specific configurations to meet diverse application requirements.
Core advantages and technical highlights
Flexible relay configurations: The 3500/25 series offers multiple relay configurations across variants, with the standard configuration featuring 8 independent Form C relays in a 2-slot form factor. Each relay provides normally open (NO), normally closed (NC), and common contacts, allowing versatile wiring to control systems, annunciators, or shutdown circuits. This flexibility eliminates the need for external relay panels in many applications.
Rapid response capability: With relay activation times under 10 ms, the 3500/25 series ensures immediate protective action when critical alarms are detected. This speed is crucial for preventing machinery damage in scenarios involving sudden vibration spikes, overspeed conditions, or axial position excursions in high-speed rotating equipment.
Robust contact ratings: Relay contacts in the 3500/25 series are rated for 5 A at 250 VAC or 30 VDC (with some variants offering higher ratings), making them compatible with a wide range of industrial control devices. This allows direct control of small motors, solenoid valves, and contactors, reducing system complexity by eliminating intermediate relays in many applications.
Configurable operation parameters: The series supports independent configuration of each relay for latching or non-latching operation, with adjustable time delays for both activation and deactivation. This customization enables protection strategies tailored to specific machinery requirements, balancing protection sensitivity with operational availability to prevent nuisance trips while ensuring response to genuine faults.
Typical variants and applications
Standard relay variant (exemplified by 184684-01)
The most common variant in the series, typified by 184684-01, features 8 Form C relays with standard contact ratings. This variant serves as the workhorse of the series, widely used in turbine protection, compressor safety systems, and manufacturing line protection. Its balanced combination of relay count, contact rating, and response time makes it suitable for most general industrial protection applications requiring multiple protective actions.
High-power relay variant
Specialized 3500/25 variants offer higher contact ratings (up to 10 A) for applications requiring control of larger loads such as motor starters or heavy-duty contactors. These variants are ideal for direct control of high-power shutdown circuits in large machinery where intermediate relays would add unnecessary complexity.
Enhanced environmental variant
Ruggedized variants in the 3500/25 series feature extended operating temperature ranges (-20°C to +70°C) and enhanced resistance to vibration and electromagnetic interference. These modules are designed for harsh environments such as offshore platforms, mobile equipment, and industrial facilities with extreme temperature fluctuations.
BENTLY 3500/25
System integration ecosystem
The 3500/25 series integrates with key components in the 3500 ecosystem:
3500 series racks provide physical mounting and backplane connectivity for relay modules
Monitoring modules (including 3500/44M 176449-03) supply alarm signals to trigger relay actions
3500 power supplies (like 3500/15 106M1079-01) provide regulated power to the relay modules
Communication modules such as 3500/05-01-03-00-00-00 enable configuration and status monitoring
Cables including 133292-01 facilitate communication between relay modules and configuration tools
Configuration modules like 136180-01 program relay logic and operational parameters
Display modules such as 3500/60 163179-01 visualize relay activation status and alarm conditions
This integrated approach ensures a complete protection loop from measurement to action.
Installation, commissioning and maintenance guidelines
Installation
Install 3500/25 modules in compatible 3500 series racks with appropriate power supplies. Ensure two adjacent slots are available, typically positioned near monitoring modules for efficient backplane communication. Connect control wiring to relay terminals using proper wire gauge (14-22 AWG) and torque (0.5-0.6 N·m) for terminal screws. Use shielded cables for sensitive circuits and route wiring separately from power conductors to minimize interference. Establish communication links to configuration tools via compatible cables for setup and monitoring.
Commissioning
After installation, configure the module using compatible configuration tools or via communication modules. Program each relay’s function, including associated alarm sources, latching behavior, and time delays. Test relay operation by simulating alarm conditions from connected monitoring modules, verifying both contact activation and proper status indication. Confirm that protective actions (such as shutdown circuits) function correctly when relays activate, and ensure deactivation behavior meets safety requirements. Document relay assignments and test results for future reference.
Maintenance
Include 3500/25 modules in quarterly safety system inspections. Verify status indicators function correctly and inspect relay contacts for signs of pitting or corrosion. Perform annual contact resistance testing using a micro-ohmmeter to ensure contacts remain within specification (<100 mΩ). Test relay operation by manually activating each relay through configuration software and verifying proper response. Clean terminal blocks annually using approved electronic contact cleaner and tighten any loose connections. Replace modules if relays fail to operate correctly or contact resistance exceeds specifications.
Service and guarantee commitment
Bently Nevada provides comprehensive support for the 3500/25 series, including a 36-month warranty covering manufacturing defects and performance issues across all variants. This includes relay reliability, response time, and component durability when used with compatible power supplies. Our technical support team offers expert guidance on relay configuration, safety system integration, and troubleshooting interactions with other system components.
We provide specialized training on relay logic programming, safety instrumented system design, and maintenance procedures specific to the 3500/25 series. Beyond the warranty period, our service agreements include functional testing, contact cleaning, and expedited replacement services to ensure continuous protection system operation. Bently Nevada’s commitment to quality ensures reliable protective action capability throughout the modules’ operational lifecycle, backed by our global network of service professionals.
