NN IEE-06-01. Microprocessor protection device of an asynchronous electric motor

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The development is intended for disconnecting three-phase asynchronous electric motors to avoid their failure in emergency situations:

disappearance of supply voltage in one of the phases;
violation of the phase sequence;
an increase in the current consumed by the electric motor in one or more phases above the permissible value;
increasing the asymmetry of the phases of the supply voltage beyond the permissible level;
delayed start of the electric motor – the starting current does not decrease during the controlled time;
an increase in the transient resistance of contacts in power circuits, automatic

The new quality is obtained thanks to software and hardware tools
Functional capabilities of the device allow you to use it as a controller, for example, to turn off the electric motor when it goes into idle mode (pump electric drive, etc.)
This device also supports blocking the next start of the electric motor after its emergency shutdown
The device can be used to control other three-phase electric consumers:
- synchronous electric motors;
- transformers and other consumers that require protection against emergency modes. machines, starters, etc.

The device consists of an electronic unit of three sensors for measuring the load current in the phases of the electric motor; indication of working and emergency modes is carried out with the help of LEDs, the output circuits of the device are connected to the circuit of the starter coil of the electric motor
Control of the electric motor starter is non-contact;
The device is a self-learning microprocessor system for direct control of a three-phase electric motor
Manual input of information is not required for the protection device, this operation is performed automatically in learning mode at the first start of the electric motor
Disconnection of the electric motor in case of overload is carried out with a dependent time delay, which depends on the value of the overload and varies within wide limits, which allows to reduce the number of emergency disconnections of the electric motor due to selective action during protection

The supply voltage of electric motors	up to 1000 V
The rated power of the electric motor connection ranges	from 1.2 to 200 kW
The permissible value of the unsymmetry of the supply voltage phases	10%
Uncontrolled acceleration time of the electric motor	up to 4 seconds
Rated starter coil voltages	660, 400, 230, 127, 110, 60 or 36 V
The supply voltage of the device	230 V at a frequency of 50, 60 Hz
Voltage deviation	from -15% to + 10% of the nominal value
Power consumption	5 VA
The nominal load current of the switching device (starter coil)	4,0 A
The minimum tripping time in case of overload	0.1 sec
The device is operable in closed rooms at temperatures	from – 10⁰C to + 50⁰C
The device is operable in closed rooms with an ambient humidity	of 80% at + 35⁰C
Operation mode	Continuous
The weight of the device without sensors	does not exceed 0,6 kg
The overall dimensions of the electronic unit	140x140x60 mm

Financing