The size of the resistors is kept to a minimum thanks to, what Reo calls, a novel manufacturing technique. This involves sealing resistance coils within an aluminium heat-sink extrusion that incorporates a thermo-dynamic filler which transfers the heat to the outer cooling surfaces.
The resistors are designed for 100% duty cycle and, according to Reo, can be custom engineered to fit into awkward spaces. The standard range extends up to 15kW but larger power ratings are possible by connecting modules in series and parallel depending on the current and resistance values required by the application. It is also possible to have EMC fittings for connection to the DC link of a frequency drive.
Reo added: “The unique construction of the resistors allows them be used without protective covers in areas where damp and dust problems could arise.”