Danotherm Bi-Alpha resistors are moderate-power resistors with a highly compact design. These resistors come in three different sizes, making them very convenient to use in applications where available space is very limited.
Bi-Alpha resistors have a flat construction with profile heights ranging from 4.3 to 5.25 mm. Aluminum and zinc alloy materials for the housing ensure good thermal properties. The resistive elements are wire-wound on a mica substrate, then insulated on both sides by mica sheets.
Power ratings for Bi-Alpha resistors range from 45 to 175 W, and the working voltages are 600 VAC / 850 VDC. Depending on the resistance, the resistors can handle up to seven times the nominal power rating for a 5-second pulse/120s.
The resistors dissipate heat by employing forced air cooling, and the nominal power ratings are specified for 2 m/s air flow rate. Increasing airflow rate increases Bi-Alpha power ratings.
The connection leads on the resistors are high-temperature silicon rated at 250 ºC. Cables with custom lengths and with cable shoes or connectors are available.
Bi-Alpha resistors are IP50 rated. Danotherm Bi-Alpha resistors have been designed as cost-effective braking resistors for small to medium power drive systems where height is an important factor.