OFEL manufactures high quality power ROF armoured resistors in aluminium cases with a high level of protection IP54. These are designed to be easily integrated in control equipment of brushless or inverter-controlled motors.
Their best performances are guaranteed when they are installed in contact with the inverter's heatsink or in contact with a metallic side of the cabinet.
Their particular shape is designed to allow for maximum use of space.
Their shape makes insertion easy. All resistor materials are incombustible and in particular, the winding is covered with cement that has a high thermal conductivity, high insulation, and is totally humidity insensitive.
Electric characteristics are:
* Standard tolerance on resistive value - ±5%.
* Temperature coefficient - <100 ppm/°C.
* Max working voltage - 1000 V.
* Standard cable length/material - 250 mm/Cu/Ni with antitearing silicone protection.
* Resister filling - high thermal-conductivity inorganic materials.
* Resistive element - alloy with a high content of nickel.
Different cable lengths and the application of a Klixon-NC thermal-contact are options. Nonstandard ohmic values are also possible.
Series ROF can also be used as anticondensation heating devices.