IP68 Cable Gland for Railway Signal Systems | Metro ATP ATO Cabinet Sealing Upgrade Case

Metro Signal System Cable Sealing Upgrade

IP68 Cable Gland Application in ATP/ATO Control Cabinets

1. Project Background

This project involved a comprehensive upgrade of cable entry sealing systems for ATP (Automatic Train Protection) and ATO (Automatic Train Operation) equipment cabinets across all 27 stations of Metro Line 3.

After 11 years of operation, the original rubber sealing gaskets had aged and hardened, resulting in sealing failure at cable entry points. Two incidents of rainwater ingress had already caused signal transmission errors, posing potential risks to railway operation safety.

Customer: Metro Rail Transit Group – Operations Division
Line: Metro Line 3 (42 km total length, 27 stations)
Project Type: Existing line overhaul and upgrade
Completion Time: August 2024 (annual maintenance window)

2. Application Scenarios and Challenges

2.1 Application Scenarios

Sealing upgrade of multi-cable entry points in ATP control cabinets
Protection of 48V DC power cables and CAN bus connections in ATO main control units
Sealing of shielded signal cables from trackside transponders to cabinets
Multi-core cable entry sealing in platform screen door (PSD) control systems

2.2 Key Challenges

Sealing Failure: Rubber gaskets degraded over 11 years, protection rating dropped from IP54 to below IP33
Water Ingress Risk: Two recorded incidents of rainwater intrusion causing signal errors
Flame Retardancy Non-Compliance: Standard plastic components failed to meet EN 45545-2 HL3 requirements
Extremely Limited Maintenance Window: Only 3 hours daily (02:00–05:00), requiring ultra-fast installation

2.3 Key Technical Requirements

Protection Rating: IP68
Material: PA66 V0 flame-retardant nylon + EPDM weather-resistant sealing ring
Flame Retardant Standard: EN 45545-2 HL3, UL94 V-0
Operating Temperature: -40°C to +100°C
Thread Types: M12 / M16 / M20 / M25 / PG7 / PG9 / PG11
Vibration Resistance: IEC 60068-2-6 (10–2000 Hz / 10g)
Certifications: CRCC (in process), CE, RoHS, IP68

Installation Requirement:
Single-hand tightening, anti-drop locking claw design, installation time ≤ 3 seconds per unit

3. Product Configuration

Product / Component	Model	Application Module
High-reliability multi-core signal connector	RAIL-SIG-64P-HL3	ATP/ATO control cabinet I/O interface
Anti-vibration self-locking circular connector	RC-M23-17P-VB	ATO power and CAN bus interface
Shielded cable waterproof cable gland	SHD-M16-SC-IP67	Transponder to cabinet signal cable sealing
Platform screen door quick-lock connector	PSD-QLC-26P	PSD control cabinet interface

4. Cable Gland Solution

Following on-site inspection and technical evaluation, an optimized cable entry sealing solution was implemented, centered on IP68-rated flame-retardant cable glands designed for railway signal systems.

These cable glands were specifically selected to ensure reliable sealing, vibration resistance, and compliance with stringent railway fire safety standards.

Key Advantages of the Cable Gland Solution

IP68 Waterproof Sealing
Effectively prevents rainwater ingress and ensures stable signal transmission
EN 45545-2 HL3 Flame Retardant Compliance
Meets strict railway fire safety requirements for enclosed electrical systems
Anti-Vibration Locking Structure
Locking claw design prevents loosening under continuous train-induced vibration
Ultra-Fast Installation
Enables installation within seconds, fully compatible with short maintenance windows
Long-Term Durability
PA66 V0 material combined with EPDM sealing ensures resistance to aging and harsh environmental conditions

Supporting Services

Provision of EN 45545-2 test reports and CRCC certification documentation
Deployment of two engineers for on-site maintenance support
Full-line FAT (Factory Acceptance Testing) after installation
Issuance of sealing performance verification reports

5. Results and Customer Feedback

Following the upgrade, all cable entry sealing tests passed, and the system achieved stable operation with zero signal errors over a six-month period.

“After the upgrade, all cable entry sealing tests passed, and no signal errors were recorded over six months. The locking claw design ensured that connectors remained secure under train-induced vibration. Installation time was reduced to less than 3 seconds per unit, making it five times faster than previous methods.”
— Senior Engineer, Signal Maintenance Department

Performance Improvements

Metric	Result
Signal anomaly occurrences	0 in 6 months (previously 19/year)
Contact resistance (average)	4.2 mΩ (better than 10 mΩ requirement)
Connector installation speed	2.8 seconds per unit
Lock loosening rate	0% (previously 7.3% per year)

6. Conclusion

This project highlights the importance of selecting high-performance cable glands for railway signal systems, particularly in environments requiring strict sealing, flame retardancy, and vibration resistance.

For metro systems, ATP/ATO cabinets, and other safety-critical railway applications, properly engineered cable glands play a vital role in ensuring long-term operational reliability and safety.

Reliable Cable Sealing for Railway Infrastructure

For demanding railway and metro applications requiring certified, flame-retardant, and high-reliability sealing solutions, YDT delivers cable gland systems engineered for safety, durability, and long-term performance.