These resistors belong to the lower power ratings of the aluminium housed types. They are mostly used in DC-links for charging and de-charging and in small inverter drives systems as brake resistor.
Aluminum is chosen as the material for the housings because it is non-corrosive, non-magnetic, lightweight yet durable, and is an excellent conductor of heat. The resistors are fully insulated and have no external live parts.
The nominal power ranges from 42 – 190W with natural air convection cooling. Higher power can be achieved with an additional heatsink or by forced air cooling. Working voltage according to UL: 600VAC / 850VDC and according to IEC: 690VAC / 975VDC. Standard ingress protection is IP50, optional IP54 can be offered. The electrical connection are 300mm long high temperature cables. Otherlengths are available on request. The cables are AWG 16 – AWG 14 and are selected depending on Ohm value and nominal power rating.
The overload factor depends on the Ohm value and the size of the resistor and range between 7 to 20 times the nominal power rating over 5 seconds. A thermal switch is available as an option for overtemperature signaling.