Industrial metal grid resistors and metal grid resistor blocks are used as brake resistors, filters, crowbar resistors and loadbanks. Depending on Ohm value, the type of grid is selected. The power load determines the number of needed grids and the size of the cabinet. They are offered in IP00, IP10, IP13, IP20 and IP23.
Neutral Earthing resistors are used to limit a fault current when a short circuit arises between phase and neutral. The NER is designed to withstand the nominal current of the system during a given time (often 10 or 30 seconds). The fault current can trip an over current relay and switch off part of the grid. NER’s are offered with and without a current transformer.
Filter resistors are offered in voltage of 12 / 17.5 / 24 / 36 / 52 / 72.5 kV in IP00 and IP23. Filter resistors are used in in power grids to improve the quality of the grid by filtering out higher harmonics. In many cases filter resistors need to comply with local directives. Danotherm offers filter resistors that comply with CIGRE WG 14.30 section 17 (specifications and design for AC filter in HVDC applications), IEC 60071-1 (insulation coordination) and IEC 60529 (Ingress Protection)
IEC 60322:2001
IEC 61373:2010
UNE-EN 50124-1:2001
UNE-EN 50125-1:2001
ANSI/IEC 60529:2004
Brake resistors for Railway applications can be positioned on the roof, under the frame or inside the vehicle in a special compartment. Traction brake resistors are constructed according legislation and international directives. They are always customized and tailored to the ambient conditions such as air temperature, humidity, mechanical forces and dimensions. Test for homologation on vibration, fire and smoke and humidity are performed at external test facilities close to the factory.