The ISRA-TM60 is an Automatically Resettable Trip Switch with SIL4 safety level based on 2oo2 diversity microcontroller architecture. Trip Switches are used as protection upstream of user loads of the railway network (signals, switchgear boxes, other equipment).
The ISRA-TM60 is particularly useful in situations where the exceeding of tripping currents is not due to faults in the devices downstream of the switch but to transient or environmental conditions (storm discharges or strong induced electromagnetic disturbances): in these cases, in fact, the automatic reset restores the operating conditions in a few seconds, without maintenance interventions, avoiding unavailability of the downstream equipment. At the same time, if abnormal absorption conditions persist, after a certain number of rearmament attempts, the ISRA interrupts the attempts, in order to preserve all parts of the system and ensure the general safety level.
The use of microcontrollers and the design choices adopted make the ISRA a widely configurable device that allows Mechanical Technologies to replace almost all the models of Latching Switches currently in use on the Italian railway network with a single device.
ISRA performs several functions at the same time:
Magnetic switch with tripping current configurable via hardware during installation in a variable range from 0.1 to 25 A.
Thermal switch with user definable I2t
RCD with user definable I2t
The recovery times and the maximum number of rearming attempts are linked to the type of trigger selected. The ISRA can be installed indifferently upstream of 48Vdc or 150Vac loads by acting on a simple selector and is compatible with the mechanical interface of the switches currently installed on the network. The device is protected from voltage dips (even of tens of seconds) and is able to reset itself even in the absence of power supply.
The ISRA is equipped with a self-diagnostic system that allows you to safely check (SIL4) any internal anomalies (status of the contacts, status of the measurement channels, etc.) and is also equipped with an LCD display and LEDs that allow you to signal operator such anomalies. Through the same display it is possible to read the current absorbed instantaneously by the load and the main configuration parameters of the device.
ISRA consumption is extremely low (<30mA)
The ISRA-TM60 guarantees a SIL4 safety level in accordance with CENELEC 50126 standards; 50129; 50128 •