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. CAR resistors have an aluminium housing with cooling fins for increased surface area, allowing faster cooldown time, hence shorter power cycles times.
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 105 – 410W with natural air convection cooling. Higher power can be achieved by forced air cooling. Working voltage according to UL: 600VAC / 850VDC and according to IEC: 690VAC / 975VDC. Standard ingress protection is IP50, optional IP54/65 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 on Ohm value and nominal power rating.
The overload factor depends on the Ohm value and the size of the resistor and range between 5 to 15 times the nominal power rating over 5 seconds. A thermal switch is available as an option for overtemperature signaling.