E-T-A electronic circuit protector saves space and installation time

E-T-A Circuit Breakers, quality designer and manufacturer of a broad range of electro- mechanical and electronic products for circuit protection, has introduced a new electronic circuit protector providing active current limitation for selective protection of load circuits powered by 24V DC power supplies in industrial and building automation applications. The new E-T-A REF 16-S is a single pole overcurrent circuit protector with a purely electronic trip characteristic taking up just 12.5mm width in a control cabinet. Like the recently introduced E-T-A 2216 it fits the E-T-A 80plus and 81plus sockets, reducing wiring and installation time. Type REF16-S allows a cost-optimised integration of overcurrent protection into a compact decentralised control cabinet.

Like the recently introduced E-T-A 2216, the E-T-A REF16-S has specifically been designed for side-by-side, snap-in installation in new E-T-A rail-mountable sockets - the 80plus (with screwless PT connecting terminals) or the 81plus (with screw terminals). The sockets allow time-saving power distribution and signalling by means of plug-in type jumpers. In addition, coding pins ensure ease of allocation between breaker and socket according to the “lock-and-key principle”. The dimensions of type REF16-S with socket meet the requirements of the DIN 43880 standard (built-in equipment for electrical installation).

Selective load protection by the E-T-A REF16-S is available in current ratings 1A, 2A, 3A, 4A and 6A and it only disconnects the faulty path in the event of an overload or short circuit in the load circuit without any repercussions on the 24V DC supply. Thus voltage dips are prevented in the event of a failure in one single circuit, without leading to a failure of all loads connected to the switch-mode power supply.

Type REF16-S limits the short circuit current to typically 1.25 times rated current and disconnects the faulty path after 800ms at the latest. However, inrush current peaks or peaks during normal operation will be tolerated. It is therefore no problem to switch capacitive loads up to 20,000µF. In the event of an overload the integral power MOSFET disconnects promptly from 1.25 times rated current.

A multi-coloured LED provides visual status and failure indications. Signalling can optionally be made available by an integral short-circuit-proof status output or auxiliary contacts. Remote operation is also possible via 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.


E-T-A designs and manufactures a broad range of electro-mechanical and electronic products for circuit protection, control and instrumentation, including the world’s largest range of circuit breakers for equipment (CBEs). E-T-A equipment is specified and installed by a wide variety of industrial OEMs and end-users, with key markets including air, sea and land transport, process control, computers and communications, medical equipment, domestic appliances, machine tools and robotics.

E-T-A is an international company with headquarters in Altdorf, Germany and production facilities in several other countries, together with marketing, sales and technical operations throughout the industrial world. Its European, North American and Far Eastern markets are served by some 1,300 employees.