MARECHAL® technology: reliable and safe connections, even above 125 A

All MARECHAL® brand technology is adapted to high power connectors. Why is this so? The end-to-end contact connection is the secret of reliable and safe products. Zoom on the subject. What are high-power sockets? We gave the answer in this article: it’s an electrical socket whose rated current can exceed 125 A for connecting heavy machinery and generators.

Regulations to improve safety

“Innovation for safety” is MARECHAL ELECTRIC’s motto. The European Low Voltage Directive, a regulation that sets objectives in terms of the health and safety of people and property, requires our equipment to comply with certain standards. This ensures our customers that the product is safe. For field applications requiring more than 125 A, MARECHAL ELECTRIC has developed several solutions, innovating to go beyond the minimum safety and performance requirements. Four main standards surround socket-outlet systems:

What does IEC/EN 60309-1 define?

It imposes electrical and mechanical performance and safety rules. It applies to all manufacturers of sockets for industrial use, up to 800 A. It proposes a minimum level of requirements for industrial environments, without any obligation of means. This level of requirement in no way constitutes a guarantee of results. In other words, if a product is suitable for any industrial application, it must comply with the IEC/EN 60309-1 standard, although this compliance is not a guarantee of validity for all applications. The application environments of the products concerned by this standard must be studied beforehand and the products must be chosen carefully to ensure that they will operate normally. MARECHAL ELECTRIC’s position is to design products that go beyond standards to meet the requirements of industry players whose needs are greater. For example, the IEC/EN 60309-1 standard dictates the need to limit overheating or make it impossible to access IP2X active parts (impossible to put your finger in the plug). Our products are all IP4X (impossible to access active parts, even with a screwdriver). In addition, it imposes a minimum of IP23 (dust and water tightness): our products are at least IP44 and most are IP66/IP67. Above 800 A, the dimensions of the conductors are such that the use of a plug becomes difficult or even impossible, in particular because of the mass of the cable. The use of single-conductor cables and single-pole connectors can therefore meet the need for flexibility for currents in excess of 800 A.

*data taken from technical data sheets for a flexible industrial cable type H07RN-F What about IEC/EN 60309-4? It has the same objective as the IEC/EN 60309-1 standard but for products including an interruption device. This is the case for MARECHAL® products which integrate this device into the socket outlet up to 250 A. This means they take up much less space than sockets that can be deactivated using a rotary switch, for example. Above 250 A, a control system is used to interrupt the supply.

What are the constraints imposed by the IEC/EN 60309-2 socket-outlet standard?

It imposes construction rules on any manufacturer of sockets for industrial use wishing to allow compatibility with other manufacturers complying with the rules of this standard, up to 125 A. This standard implies that the male (or female) part of a manufacturer A can be inserted into the female (or male) part of a manufacturer B, ensuring the passage of current. It imposes minimum performance requirements: – electrical: contact temperature rise, – mechanical: number of connection/disconnection cycles, – environmental: protection of active parts. It also defines dimensional constraints, imposes a technology (pins and sockets) as well as materials (brass) and plating (zinc). Above 125 A, the additional constraints required for inter-compatibility mean that sufficient performance can no longer be guaranteed. For example, other types of contact, such as silver-nickel contacts, are better suited to higher currents than pin-and-cell technology, whose electrical performance is not optimal. The imposition of means in IEC/EN 60309-2 also gives rise to other difficulties: the poor electrical performance of oxidised contacts, the operating difficulties caused by the large clearances required for inter-compatibility, and the difficulty of ensuring ancillary functions such as sealing. The mechanical solutions found to remedy the limitations of the IEC/EN 60309-2 standard sometimes impose other constraints.

MARECHAL ELECTRIC’s strength: end-to-end contact technology

This technology is suited to the need for strong, regular connections, and to the industrial market. It provides a reliable and safe connection, for a market that requires regular connections and disconnections, without losing the quality of the connection. The ergonomics and technology of MARECHAL® products make them an everyday ally in improving the safety of operators and installations in industry.