Self-Stripping Technology Offers Significant Cost Reductions For Railway Industry
29 March 2007
Phoenix Contact has launched the first application using self-stripping junction box technology in passenger information systems for SNCF trains operating on suburban Paris routes.
SNCF French Railway's Rennes Rolling Stock Shop is responsible for maintaining and renovating trains from the Paris Region. These operations generally take place every twenty years and make it possible to add another twenty years to the rolling stock's theoretical service life. This facility has just delivered the first trains to use self-stripping junction block technology that does not require any dedicated fitting tools to enter service anywhere in the world. This innovation was developed by Phoenix Contact, whose products are already on numerous trains throughout the world. The product used in this new application is the Quick Terminal Compact (QTC), a self-stripping terminal block. It allows for considerable time savings when the application entails the fast connection and disconnection of subassemblies.
The junction blocks involved are part of the system for controlling and powering the on-board passenger information systems known as SIVE.
Using self-stripping technology, the cost of each connection point is halved compared with the costs observed when using other connection technologies. In contrast to Faston, regularly used in railway applications and spring-loaded connectors, this type of connection is the fastest. There is no longer any need to strip the wire or reinforce it with an end, as is necessary in railways applications when using spring-loaded connectors. The tooling required is minimal: all that's needed is an ordinary screwdriver to actuate the connection mechanism. The result is truly simple component stock and tooling management. Maintenance operations are performed just as easily, both for connecting or disconnecting.
The savings may appear negligible, but in practice it is of considerable importance: of the 350 people in the unit responsible for train renovation, 30 people are tasked with wiring. We estimate that this cost accounts for 4% to 5% of the renovation budget for each train. For new rolling stock, the proportion is between 2% and 3%.
Since March 10, 2005, the QTC terminal block remains the first one to receive LT/CIM ZET/2005-1360 approval for use granted by SNCF through the Rolling Stock Establishment, CIM. It is important to mention that the product used was not modified in any way to pass qualification tests. The terminal blocks used are therefore the same as those tried and tested in numerous industrial applications. Among the qualification tests, we should note temperature resistance (100°C for 1,000 hours), accelerated ageing (fast temperature variations from -40°C to 100°C), impact resistance (30G), full-time vibration at 6G and exposure to a salt mist for 144 hours.
In principle, approval for use in safety related functions will be granted on expiry of a three-year probation period. At that time, the self-stripping blocks will be usable in functions like alarm signal systems, speed control by markers and one person operation.
