BENTLY NEVADA 3500/15 106M1079-01 | Dual Redundant Power Supply | Critical Obsolescence Advisory for 3500 Protection Systems
BENTLY NEVADA 3500/15 106M1079-01 | Dual Redundant Power Supply | Critical Obsolescence Advisory for 3500 Protection Systems - Image 2
BENTLY NEVADA 3500/15 106M1079-01 | Dual Redundant Power Supply | Critical Obsolescence Advisory for 3500 Protection Systems - Image 3
BENTLY NEVADA 3500/15 106M1079-01 | Dual Redundant Power Supply | Critical Obsolescence Advisory for 3500 Protection Systems - Image 4

BENTLY NEVADA 3500/15 106M1079-01 | Dual Redundant Power Supply | Critical Obsolescence Advisory for 3500 Protection Systems

  • Model: 3500/15
  • Part Number: 106M1079-01
  • Brand: Bently Nevada (a Baker Hughes company)
  • Core Function: Dual-input redundant power supply module for 3500 Machinery Protection System chassis
  • Lifecycle Status: Obsolete – no longer manufactured; superseded by updated 3500/15 revisions and 3500XP platform
  • Procurement Risk: High – extremely limited verified inventory; units often sourced from decommissioned systems with unknown service history
  • Critical Role: Provides regulated +24 V, ±12 V, and +5 V DC to all I/O and controller modules in the 3500 rack; single point of failure if redundancy is compromised
Category: SKU: Bently Nevada 3500/15 106M1079-01

Description

Key Technical Specifications (For Spare Parts Verification)

  • Product Model: 3500/15
  • Part Number: 106M1079-01
  • Manufacturer: Bently Nevada
  • System Platform: 3500 Machinery Protection System (standard and enhanced racks)
  • Input Voltage: 85–264 V AC, 47–63 Hz (dual independent inputs for redundancy)
  • Output Voltages: +24 V DC (for transducer power), ±12 V DC, +5 V DC (for logic/backplane)
  • Output Current Capacity: +24 V @ 2.5 A max; total combined output ~100 W
  • Redundancy Mode: Active-active; automatic load sharing and failover
  • Status Indicators: Front-panel LEDs for AC input presence, DC output OK, and fault conditions
  • Mounting: Full-height module occupying one slot in 3500 chassis (typically slot 0)
  • Cooling: Convection-cooled; relies on chassis airflow
  • Revision: Early production variant (Rev A/B); lacks modern diagnostic features of later models

System Role and Downtime Impact

The 3500/15 power supply is foundational to the operational integrity of the entire 3500 rack. It powers not only I/O modules but also proximity probes (via +24 V) and internal logic circuits. While designed with dual-input redundancy, many legacy installations use only one AC feed due to site constraints—effectively operating without backup. In such cases, a single power supply failure results in complete loss of machinery protection, forcing an immediate process shutdown to avoid catastrophic equipment damage.

Even in fully redundant configurations, degradation in one supply can cause voltage instability that triggers intermittent faults across multiple I/O cards, leading to nuisance alarms or data corruption. Because the 3500/15 cannot be hot-swapped in most legacy racks, replacement requires a controlled outage—making proactive spares management essential in continuous-operation environments like refineries, LNG trains, or power plants.

 

Reliability Analysis and Common Failure Modes

Despite its robust design, the 3500/15 (106M1079-01) is highly susceptible to component aging due to continuous thermal stress. The most frequent failure mechanisms include:

  • Electrolytic capacitor drying in the primary-side filtering and secondary-side regulation circuits, leading to output ripple, voltage droop, or complete shutdown.
  • Failure of switching transistors or rectifier diodes due to repeated thermal cycling, especially in high-ambient-temperature enclosures.
  • Corrosion or oxidation on AC terminal blocks or internal PCB traces in humid or corrosive industrial atmospheres.

A key vulnerability is the lack of comprehensive self-diagnostics in early revisions; the module may continue operating with degraded output margins without triggering a visible fault LED until failure is imminent. Additionally, the absence of power-factor correction (PFC) makes it more sensitive to poor-quality AC input, accelerating wear on internal components.

Maintenance best practices include: performing annual infrared thermography to detect hot spots, verifying output voltages under full load using a calibrated multimeter, inspecting terminal torque and wire insulation, and ensuring adequate ventilation around the chassis. Any unit showing flickering status LEDs or unexplained system resets should be replaced immediately.

Bently Nevada 3500/15 106M1079-01

Bently Nevada 3500/15 106M1079-01

Lifecycle Status and Migration Strategy

Bently Nevada has discontinued the 106M1079-01 revision of the 3500/15. While newer 3500/15 variants (e.g., 106M1079-02 or -03) offer improved reliability and diagnostics, they are also approaching end-of-life as the industry transitions to the 3500XP platform.

Continued reliance on this obsolete power supply introduces severe operational risk: no factory repair services, inability to validate performance against original specifications, and increasing likelihood of counterfeit or misrepresented units in the secondary market.

As an interim measure, facilities should secure at least one fully tested spare unit and validate its output stability under simulated load conditions. Board-level refurbishment by qualified third parties—focusing on capacitor replacement and thermal inspection—is a viable option for extending service life.

For long-term resilience, migration to the 3500XP system is recommended. The 3500XP uses a modernized power architecture with enhanced diagnostics, higher efficiency, and compatibility with global voltage standards. While migration requires chassis replacement, existing field wiring can often be retained via terminal block adapters. Until then, rigorous testing of installed and spare 3500/15 units is critical to prevent unplanned outages caused by power-related failures.

Related products