Patented ETIMAT P construction for a longer service life
The new construction of ETIMAT P miniature circuit breakers, protected by two European patents, ensures a superior electrical endurance and highest electric strength. Unique on the market, a combined thermo-magnetic tripping unit enables precise and reliable shutdown and prevents manual tampering of the overload settings. ETIMAT P are versatile, strong and durable and designed to rationalize mounting and usage.
 | Domen Janc R&D |
As the advantages of the new generation of ETIMAT P, we can point out reduced power dissipation, longer lifetime of the product, less impact on the environment during the production of the devices, as well as their automated assembly of the product ensures precise traceability and the highest quality control. Each product has a QR code with a link to the product website with all the relevant information, operating instructions and other technical materials. The miniature circuit breaker can be connected to the busbar and conductor at the same time, both from above and below, using wires with a connecting crossection up to 25mm2.
Construction of new generation ETIMAT P
With the new construction, we reduced the number of technological processes, especially the number of necessary welds, which we succeeded in with the new patented assembly of the movable contact. This new construction also enables complete automation of product assembly.
We also wanted to improve the functionality of the new generation of devices in tests of the short circuit capacity, which we succeeded in by constructing new parts of the mechanism. The new mechanism provides adequate tripping dynamics, contact opening speed and has one of the largest final inter-contact distances, which means improved dielectric breakdown strength. It also enables easy connection of single-pole devices into multi-pole versions and quick and easy installation of existing ETI accessories (auxiliary switches, remote switch-off switch, etc.) by end users and, of course, their reliable operation.
The assembly of the movable contact - a patented solution
The most original design solution in ETIMAT P is represented by the composition of the movable contact with, which enables:
- adequate contact force
- corresponding decreasing torque on the movable contact when the mechanism is switched off (dynamics when opening)
- a very large inter-contact distance (improved dielectric breakdown strength in the off state) and
- provides a superior number of cycles in lifetime tests (on/off).
The assembly ensures adequate mobility of the flexible contact and electrical conductive properties without the need to use flexible copper braids or to weld individual parts.
Assembly of the movable contact ETIMAT P
Combined tripping unit – a patented solution
The heart of ETIMAT P is the so-called combined tripping unit, which combines the function of thermal tripping, conditioned by the occurrence of a long-term current overload, and instantaneous electromagnetic tripping, conditioned by the occurrence of a short-circuit current. Other miniature circuit breakers on the market have thermal tripping units separate from the electromagnetic one, but in ETI's solution, both are combined into one assembly.
Electromagnetic tripping unit with a magnetic coil
The magnetic coil is different for each characteristic. As a consequence, the MCB doesn’t need any additional adjustments, and there is no possibility of manual tampering.
Integrated thermal release with bimetallic disc
This part of our patented innovation works as a substitute for the long bimetallic strip used in other MCBs. This solution prevents degradation of the bimetallic strip due to permanent electrical loading of the material. This ensures a stable, unchanged tripping characteristic of each ETIMAT P during its entire lifetime.
Operation of the combined tripping unit
In the event of an electrical overload, the increased electric current in the wire of the coil wound on the combination tripping unit generates heat, which heats the aluminum cylindrical crucible of the tripping unit. The resulting heat is transferred through the crucible to the thermobimetallic disc inside the tripping unit, which when heated reaches a specific temperature and fires the striker pin. At an even higher electric current, typical of a short circuit, the tripping unit fires instantly like an electromagnet due to the generated increased magnetic field. Then the striker pin is pushed by the movement of the magnetized iron arm against the fixed iron core, which is fixed in a pot inside the tripping unit. In both cases, the striker pin releases the mechanism and consequently causes the electrical shutdown of the device.
New, optimized arc chamber
All manufacturers of miniature circuit breakers install an arc chamber in their products, the role of which is to cool and extinguish the electric arc ("electric lightning") that occurs when the device is switched off at a high short-circuit current. It consists of iron tiles called lamellas and a supporting frame for fixing them, made of a special heat-resistant non-combustible cardboard (called "vulkan fiber").
For the ETIMAT P, we have developed a new optimized arc chamber, which has a more durable and slightly thicker casing with special round exhaust holes on the back. Round holes are an innovative solution that ensure adequate air permeability at increased pressure in short circuit conditions and at the same time successfully stop the traveling larger hot ionizing particles created under the influence of an electric arc when melting parts of conductive metal surfaces.
Arc chamber ETIMAT P
All major components are marked with a DMC code containing the individual test results, ensuring exact traceability and the highest quality control of each MCB.