Dealing with materials in the design and industrialisation of plugs and socket

Since 1952, MARECHAL ELECTRIC has specialised in the manufacturing of plugs and sockets for industrial and explosive environments. We have built our expertise thanks to our long-standing presence in various industries in which our devices are used. Getting to know each sector specific requirements is key for our R&D teams who work daily to ensure our products are suitable for harsh environments. Sectors such as mining, water treatment, food and beverage expect durable devices. We design them with this in mind. The following article explains how material issues are tackled from mechanical, chemical, and environmental points of view. 

Mechanical resistance 

Due to their location on industrial sites with the close proximity of machines, our products are exposed to high mechanical stress: heavy vibrations, risk of shocks… 

MARECHAL ELECTRIC selects enclosure material carefully to ensure the product integrity for live parts protection. Polymeric (IK09) or metallic (IK10) enclosures are available to meet every market demand depending on their requirements. Alongside with IK testing at ambient temperature, impact and drop tests are performed on all our materials within the operating temperature range. The selected materials have also high wear resistance characteristics as well as fatigue resistance that allows numerous operations without enclosure failure.

Glass reinforced plastic materials have been selected to improve mechanical performances and specifically to prevent material deformation, such as creep deformation; whatever the load used on our products and even after ageing. This allows us to guarantee the initial watertightness level in combination with the use of appropriate gaskets developed for the MARECHAL® brand by our R&D team. 




Chemical resistance 

Working with many different industries helps MARECHAL ELECTRIC to collect recurring examples of potential damage to an electrical installation which are a direct consequence of the presence of chemicals. One example is the emission of hydrogen sulphide (H2S) in refineries, blast furnaces or in water treatment plants can impact on the performance of the materials of industrial plugs and sockets. 

Consequently, our polymers are chosen to be resistant to water even at high temperature, with chlorine or salted water. They also have a reasonable resistance to a wide diversity of chemical products among them alkalis (ammonia, sodium hydroxide), alcohols, ketones (acetone), hydrocarbons. 

Our metal range can be naturally sensitive to various types of corrosion (galvanic, pitting corrosion, stress corrosion cracking, etc.), special surface treatment in combination with appropriate initial surface preparation are carefully chosen to inhibit the effect of chemicals. For enclosures, powder paints are mainly used but we also offer dedicated treatments to specific metals: anodized surfaces on aluminium, passivation for stainless steel, zinc plating. Salt mist test performances are the guarantee of the treatment effectiveness and durability. For live parts, silver or tin plating are systematically used to ensure key components have the best electrical conductivity whatever the environmental conditions. This also ensure a high-performance finish which resists the effects of time and use in aggressive atmospheres. 

Environmental resistance 

The variety of possible installations (indoor, outdoor, on and offshore…) exposes our products to the natural elements: sun radiations, cold or warm temperatures and even fire. 

This is the reason why all our polymeric materials are UL746C f1 compliant, meaning that the material performances are maintained even after being subjected to ultraviolet (UV) light exposure and water immersion. This severe testing is composed of cycles of UV exposure with xenon-arc weatherometer for 1000 hours and water immersion testing is performed for 7 days at 70°C.  

Compared to commodity polymers, our technical or high-performance polymers are suitable to be used across a wide temperature range; between -40°C (or even less for some materials) and 60°C as a minimum. We also select materials with high RTI (relative temperature index, 18 months testing) values (above 100°C) to ensure the stability of mechanical (impact and strength) and electrical properties with time and temperature

In addition 

Materials have also been selected to allow the addition of application-specific modifications to deliver tailor made products upon request.  

Please contact us for guidance for use with a specific chemical or agent.