n the basic version, the system enables heating of the contact wire supply of elevators up to a lift height of 200 m.

Standard bus bar assemblies are prone to freezing. In the winter, at temperatures around 0 °C, the moisture in the air freezes, precipitation occurs, and water from the building is sprinkled on to the slippery surface of the trolley wire power supply. The thin layer of ice on the slippery surface increases electrical resistance, and can therefore cause sparks during operation, which damage both the collectors and the actual trolley wire surface.In extreme cases, the collector can be frozen to the trolley wire.
 
For this reason, STROS developed a unique bus bar heating system. The device consists of a main heating distributor located in the lowest station beside the elevator enclosure, and a connecting distributor located at the highest point of the bus bar power supply. An advantage of the STROS system is that the heat is generated directly in the bus bar assembly by the passage of a powerful current at a low voltage; so-called direct resistance heating.
 
In its basic design, the system enables the heating of the elevator bus bar up to a 200 m lifting height, with the option of expansion to twice that much. The heating can operate in automatic mode, where its control system monitors the ambient air and bus bar temperatures, evaluates them, and if necessary switches the heating current on or off. At the same time, it's possible to programme individual days of the week, and the intervals in which the device is to be in operation, so upon arrival in the workplace the bus bar assemblies are free of frost and the elevator can be used immediately. The heating can also be switched on manually when frost is discovered. In that case, thawing takes approximately 10-20 minutes, depending on weather conditions and the thickness of the frost. Its use thus significantly reduces the amount of time necessary to start using the elevator at the start of daily operation, as well as the likelihood of the bus bar assemblies being damaged by frost, and work safety increases.
 
The first bus bar heating assemblies have already been delivered to customers in the USA, and after successful testing in real operation we received further orders.

 
Vladimír Prošek
Technical Director

Soure: https://www.stros.cz/en/news/vyhrivani-trolejoveho-napajeni-vytahu