Arrangement for overload protection and method for reducing the current consumption in the event of mains voltage fluctuations

Arrangement for overload protection of an electric motor of a compression unit having a compressor, the arrangement having a mains voltage-monitoring unit connected between a control arrangement and a mains voltage, and having a device for reducing the load on the motor, wherein the control arrangement is connected to the device for the purpose of reducing the load in the event of the mains voltage falling below a predetermined, first threshold value, and wherein the connection of the electric motor to the compressor is made via a coupling such that it can be adjusted and/or disconnected.

Arrangement for overload protection of an electric motor of a compression unit having a compressor, the arrangement having a mains voltage-monitoring unit connected between a control arrangement and a mains voltage, and having a device for reducing the load on the motor, wherein the control arrangement is connected to the device for the purpose of reducing the load in the event of the mains voltage falling below a predetermined, first threshold value, and wherein the electric motor is provided with a device for reducing the current consumption in the start-up phase of the electric motor which comprises an NTC thermistor which can be connected in series with a main winding of the electric motor, and an arrangement which can be connected in series with an auxiliary winding of the electric motor, comprising an NTC thermistor and a start-up capacitor.

Method for reducing the current consumption of an electric motor driving a compression unit having a compressor in the event of mains voltage fluctuations, comprising the steps of:

• monitoring the mains voltage and reducing the load of the electric motor caused by the compressor when the mains voltage falls below a first threshold value, such that the electric motor is running on approximately no-load, wherein the load is removed from the electric motor by means of reducing the pressure difference between the pressure at the inlet and the pressure at the outlet of the compressor by opening and/or closing one or more valves in a bypass between the inlet and the outlet of the compressor.

Method for reducing the current consumption of an electric motor driving a compression unit having a compressor in the event of mains voltage fluctuations, comprising the steps of:

• monitoring the mains voltage and
• reducing the load on the electric motor caused by the compressor when the mains voltage falls below a first threshold value, such that the electric motor is running on approximately no-load,
• wherein the current through the electric motor is reduced during the start-up phase, and during the start-up phase an NTC thermistor is connected in series with a main winding of the electric motor, and an arrangement comprising a start-up capacitor in series with an NTC thermistor is connected in series with an auxiliary winding of the electric motor.