REF16-S

Type REF16-S is an extension of the product group »Electronic Overcurrent Protection« for DC 24 V applications. It provides selective protection for all DC 24 V load circuits at a width of only 12.5 mm. This is achieved by a combination of active electronic current limitation in the event of a short circuit and overload disconnection at typically 1.25 times rated current. Plugged into an E-T-A socket, which is available with screw terminals or screwless terminals, the REF16-S provides ease of installation. The sockets allow power distribution and signalling via plug-in type jumpers. In addition the REF16-S latches on when plugged into the socket and by means of coding pins a clear assignment to current ratings or slots is possible. Dimensions are in compliance with the standard DIN 43880 for the installation of built-in units.
DC 24 V switch-mode power supplies are widely used in automation. In the event of an overload, however, they turn down the output voltage which is meant to supply all connected loads. Therefore a failure occurring in an individual load of the system causes a voltage dip in all other load circuits. This does not only lead to an undefined fault status, but may even cause a stoppage of the machinery or plant. The REF16-S responds much faster to overload conditions than the switch-mode power supply. It limits the max. possible overcurrent to typically 1.25 times rated current (see table 1). This allows connection
of capacitive loads up to 20,000 μF with disconnection only in the event of overload or short circuit. For optimal adjustment to the load conditions the REF16-S can be selected in fixed values of 0.5 A…10 A. Status and failure indication is provided by a multi-coloured LED, a potential-free signal contact or by means of an integral short-circuitproof status output. Remote actuation is possible by a remote reset signal or a remote control signal ON/OFF. The manual ON/OFF button on the device allows intentional start-up of individual load circuits. As soon as the REF16-S identifies an overload or short circuit
condition in a load circuit, it will block the load output transistor and interrupt the current flow in the faulty circuit. Upon remedy of the failure, the load output of the REF16-S will be re-activated by an electronic reset signal or by manual operation of the ON/OFF button.