Patent ID: 6285157
Filing Date: 2001-09-04
Classification: H02P

Abstract:
In a cooling system arranged in a switchgear cabinet (12), a fan cooling device for electric components, having a control circuit which has a control stage designed to control a number of revolutions of a fan motor in a form of an asynchronous motor connected to the control stage as a function of preset values, wherein the fan motor (11) is controlled by phase control, the control circuit (1) includes a microcontroller (4) connected upline of the control stage, an optocoupler (10) is switched between the control stage and the microcontroller (4), and the microcontroller (4) determines a phase control angle for control of the fan motor (11) on a basis of a detection of a crossover of current of a control signal and of the preset values and is connected to a further control device, the improvement comprisinga switchgear cabinet control (2) connected via a data bus to the microcontroller, andmeans for determining one of the switchgear cabinet control (2) or manual control, such that the microcontroller (4) controls the fan of: a) alone on a first basis of the preset values set manually by means of the revolutions setting unit (5) and the command value preset unit (7) and entered from the revolutions setting unit (5) and the command preset unit (7) directly into the microcontroller (4) and b) on a second basis of the preset values supplied through the switchgear cabinet control (2).