Danotherm CBR resistors are passive power resistors designed for efficient cooling and optimal protection against solids and liquids. They have received UL approval and come encased in compact aluminum housings. These resistors are commonly employed in small inverter drive systems as brake resistors.
Aluminum has been deliberately chosen as the housing material due to its non-corrosive, non-magnetic, lightweight, and durable properties. Moreover, it serves as an exceptional heat conductor. Notably, these resistors are fully insulated, ensuring the absence of external live parts. The primary resistive component comprises a Nickel-Chrome alloy, characterized by minimal thermal drift, enhancing precision.
The power output of these resistors falls within the range of 160 to 1700W under natural air convection cooling. This resistor series is equipped with cooling fins to optimize heat transfer. When higher power output is needed, forced air cooling can be employed. The standard working voltage adheres to UL specifications, with ratings of 600VAC / 850VDC, and complies with IEC standards at 690VAC / 975VDC. Additionally, an optional version with a 1000VAC/1400VDC rating is available.
In terms of protection, the standard ingress protection is rated at IP50, with options for IP54 or IP65 as well. Electrical connections are established using high-temperature cables measuring 300mm in length. Custom cable lengths can be accommodated upon request, with cable sizes ranging from AWG 16 to AWG 10, selected based on Ohm values and nominal power ratings.
The overload factor is contingent on the resistor’s Ohm value and size, spanning from 8 to 18 times the nominal power rating over a 5-second duration. For added safety, an integrated thermal switch can be optionally incorporated to provide overtemperature signaling.