MARECHAL® technology: a reliable and safe connection system, even above 125 A

All MARECHAL® brand technology is adapted to high power connectors. Why? The butt-style contact connection is the secret of reliable and safe products. More details below.


What is a high-power electrical socket outlet? We gave the answer in this article: it is an electrical socket outlet whose nominal current can exceed 125 A to ensure the connection of heavy machines and generators.



Regulations for better safety

"Innovation for safety" is the MARECHAL ELECTRIC’s motto.

The European Low Voltage Directive, a regulation that sets the objectives for the health and safety of people and property, requires that our equipment meets certain standards. This ensures our customers that the product is safe.

For field applications that require more than 125 A, MARECHAL ELECTRIC has developed several solutions, innovating to go beyond the minimum safety and performance requirements.


There are four main standards surrounding socket outlets:


Products concerned



IEC/EN 60309-1

Socket outlets for industrial purposes up to 800 A

General minimum requirements for performance and safety

IEC/EN 60309-2

Socket outlets for industrial purposes up to 125 A

Dimensional interchangeability requirements for pin and sleeve devices

IEC/EN 60309-4

Socket outlets for industrial purposes up to 800 A - with AC-22 minimum

General requirements for performance and safety


IEC/EN 60947-3

Industrial switches

General minimum requirements for performance and safety


What does the IEC/EN 60309-1 standard define?

It imposes electrical and mechanical performance and safety rules. It applies to all manufacturers of socket outlets for industrial use, up to 800 A.

It proposes a minimum level of requirement for industrial environments without obligation of means. This level of requirement does not constitute a guarantee of result. In other words, if a product is suitable for any industrial application, it must comply with the IEC/EN 60309-1 standard, without this compliance being 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 function normally.

MARECHAL ELECTRIC's position is to design products that go beyond the standards to meet the requirements of the industry players whose needs are more important.

For example, the IEC/EN 60309-1 standard dictates the need to limit overheating or to make it impossible to access the active parts IP2X (impossible to put the finger in the plug). Our products are all IP4X (impossible to access the 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 for the most part 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 then be an answer to the need for flexibility for currents exceeding 800 A.




4G70 (4 kg/m)

246 A

4G150 (8 kg/m)

395 A

4G240 (13.5 kg/m)

538 A

1x300 (3.5 kg/m)

693 A

*Data from data sheets of a flexible industrial cable type H07RN-F


What about the IEC/EN 60309-4 standard? It has the same objective as the IEC/EN 60309-1 standard but for the case of products including an interruption device.

This is the case of MARECHAL® which integrates this device in its socket outlets up to 250A. This allows a much smaller space requirement than that of deactivatable socket outlets with a rotary switch for example. Above 250 A, the interruption is carried out by means of a control system. 




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

It imposes construction rules on any manufacturer of socket outlets for industrial use wishing to allow compatibility with other manufacturers respecting the rules of this standard, up to 125 A.

This standard implies that the male (respectively female) part of a manufacturer A will be able to be inserted in the female part (respectively male) of a manufacturer B by ensuring the passage of the current.

It imposes a minimum as regards the performances:

- electrical: heating of the contacts,

- mechanical : number of connection/disconnection cycles,

- environmental : protection of active parts.


It defines dimensional constraints, imposes a technology (pin and sleeve) as well as materials (brass) and plating (zinc). From 125 A, the additional constraints necessary for inter-compatibility no longer ensure sufficient performance. For example, other types of contacts such as silver-nickel contacts are better suited to higher currents than pin-and-sleeve technology, which does not provide optimal electrical performance.

The imposition of the means in IEC/EN 60309-2 also creates other difficulties: the poor electrical performance of oxidized contacts, the difficulties of manoeuvring caused by the large clearances necessary for inter-compatibility, or the difficulty of ensuring auxiliary 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: the butt-style contact technology

This technology is adapted to a need for strong and regular connection, and to the industrial market. It allows 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 a daily ally to improve the safety of operators and installations in industry.