Plug and socket connectors are employed for connecting electrical lines to each other and for connecting electrical machinery and equipment to the power supply. Thermal damage and difficulty with withdrawal occur on shrouded plug and socket connectors to DIN 49462 (multi-pole shrouded plug and socket connector with earthing contact, 16 A and 32 A, over 42 V to 750 V) and DIN 49463 (multi-pole plug and socket connector with earthing contact, 63 A and 125 A, over 42 V to 750 V). The objective of the project, initiated by the working group of the institutions for statutory accident insurance and prevention in the building trade (ARGE Bau), was to ascertain the reasons for this. Proposals were to be made for supplementary technical safety requirements.
A number of damage samples were sent to the BG Institute for Occupational Safety (BIA) by various companies in the construction sector. The samples were intended to provide information on the nature of the damage. The study revealed that of the 20 damage samples received, 19 had failed as a result of thermal damage. The main causes of overheating, besides improper connection, were environmental and functional influences. Soiling and the formation of coatings of foreign matter around the contacts led to an increase in the resistance in the latter cases. The consequent power losses at the contacts resulted in failure.
Proposals for improvement of shrouded plug and socket connectors to DIN 49462/63 in consideration of the conditions in the construction sector are: prevention of contact soiling by improved ingress protection, use of contact materials with low contact resistance, use of insulating materials with high melting temperature, and improvement of the design such that the the maximum withdrawal forces on the plug and socket connector are not exceeded under the influence of temperature and moisture.
construction industryType of hazard:
accident riskDescription, key words:
plug and socket connectors, damage during use in the construction sector, soiling, coatings of foreign matter, overheating, increased ingress protection, contact material with low contact resistance, insulating material with high melting temperature, withdrawal forces