N.S1. relays are modular, plug-in relays designed for non-controlled safety
functions in railway signalling installations. The N.S1 type, normally used in
signal-boxes, is part of the SNCF ’s modern “standardized N.S1
equipment”.
The N.S1 equipment can be classified in two groups:
- The ”removable” equipment, i.e. the relay itself and its accessories
which can be plugged into the “fixed” equipment
- The “fixed” equipment comprising the N.S1 rack and accessories
(plug-in connecting boards
Operation
The removable equipment is accommodated in a separate plug-in housing. The
moving part of the plug-in connector consists of a moulded base bearing the
mechanism and the contact blades of the relay.
Only the height of the component can vary, depending on how many modules are
necessary to accommodate its constituents.
Each component is equipped with coupling and locking clamps and a set of pins,
ensuring fool-proof replacement (connecting an element other than the correct
one is impossible).
The electric connections between the fixed and the removable parts occur
through automatic plug-in pins. The contact blades of the removable part
protrude from the base so as to make contact with the front ends of the contact
blades of the fixed board.
The safety feature of such relays is ensured through simple and well proved
technological solutions, through the use of unweldable front contacts and
through the use of natural gravity in the drop away torque, so that any mishap
will always result in the drop away of the relay.
Installation
N.S1 relays, being modular, are very easy to install. They have only one
mounting position since natural gravity is resorted to as a
safety-factor.
They can be mounted either on an N.S1 rack (U-shaped profile) including rear
connections through miniature Faston clips and fixed connecting boards N.S1 -
PFC 12 or on bracket supporting fixed connecting board N.S1 - PFC - AV 24,
connecting boards adapted to horizontal shelf mounting.
All types of N.S1 relays are compliant with the NF 70 030 standard.
References
Ansaldo STS’ N.S1 Relays are installed all over the world on major projects in
Algeria, Austria, Belgium, France, Great Britain, South Africa, Tunisia,
Morocco, Thailand, Portugal, Spain, Congo, Mexico, Argentina, Chile, China,
Cameroon.
