Alstom VPS-12004-102-03-V1-0-0 Vital Power Supply for Railway Signaling Cabinets

The Alstom VPS-12004-102-03-V1-0-0 is a vital-grade power supply module designed for wayside signaling and interlocking environments where dependable 24 VDC power and built-in status monitoring are a must. From my experience, this type of “VPS” module is typically used to feed safety-related I/O, relays, controllers, and network devices in bungalows and station cabinets. One thing I appreciate is how it’s engineered for stable output and clean DC under noisy trackside conditions, which in many cases reduces nuisance trips and extends hardware life downstream.

Our Order Process and Guarantees

• Warranty: 365 days
• Lead time: 1 week if in stock; no more than one month at the latest
• Payment: 50% advance payment, full payment before delivery
• Express delivery: FedEx / UPS / DHL

Key Features

• Vital-grade 24 VDC output – Provides regulated, low-ripple DC suitable for signaling logic and controllers.
• Wide-range AC input – Typically supports 100–240 VAC, 50/60 Hz for global deployment and retrofit projects.
• Isolated design – Galvanic isolation helps cut ground loops and noise coupling in mixed vendor cabinets.
• Alarm relay contact – “DC OK” dry contact for remote health monitoring into SCADA or ATS.
• Redundancy-ready – Supports N+1 setups with external OR-ing or diode modules for uninterrupted operation.
• Rugged for wayside use – Appears to be engineered for extended temperature and high-EMI environments common near tracks.
• DIN-rail / panel mounting – Flexible installation makes swaps straightforward in most cabinets.

Technical Specifications

Application Fields

This module is commonly deployed in:

• Interlocking and signal bungalow cabinets feeding vital logic and relay banks
• Wayside communications, object controllers, and I/O nodes for trackside equipment
• Level crossing protection systems with redundant 24 VDC bus architectures
• Depot and yard control panels where stable DC and alarm feedback are required

A maintainer told us they swapped a VPS unit in under an hour during a night possession, tied the DC-OK contact into the existing ATS input, and saw ripple drop to well under 50 mV on their logger. That kind of outcome seems to be common when replacing aging supplies in mixed-vendor cabinets.

Advantages & Value

• Reliability under noise – Designed for EMC-heavy installations near traction power and track circuits.
• Compatibility – Works smoothly with standard 24 VDC signaling loads, relays, and PLCs.
• Redundancy options – Supports N+1 with external OR-ing, cutting single points of failure.
• Lifecycle savings – Clean power reduces stress on downstream electronics, typically extending service life.
• Support & spares – From my experience, quick availability of this form factor helps keep MTTR low.

Installation & Maintenance

• Cabinet environment – Install in a sealed cabinet with adequate ventilation; maintain 30–50 mm side clearance for airflow.
• Wiring – Use appropriately rated conductors for 24 VDC bus; torque terminals per label; segregate low-voltage and mains wiring.
• Grounding – Bond to cabinet earth; keep return paths short to reduce noise.
• Redundancy – For N+1, use an external OR-ing or diode module; balance loads and verify failover alarm behavior.
• Safety – De-energize and lock out mains before service; verify output discharge before touching terminals; observe ESD precautions.
• Routine checks – Quarterly: inspect terminals, measure DC ripple under load, test alarm relay operation; annually: dust removal and functional test under representative load.

Quality & Certifications

• CE marking and RoHS conformity (typical for this category)
• EMC compliance for railway environments: EN 50121-4 (wayside), tested in most deployments
• Safety per IEC 62368-1/60950; UL recognition may apply depending on build
• Manufacturer’s warranty: 365 days

Related Accessories & Supporting Components

• 24 VDC diode OR-ing modules for N+1 redundancy
• DIN-rail battery buffer / DC UPS for hold-up during short outages
• EMI line filters for cabinets with challenging traction interference
• Pre-terminated harness kits for quick retrofit in Alstom-based panels