STARTING STAR-DELTA
CHAVES MAGNETICAS

This type of starting consists of supplying the motor with a reduced voltage through the connections in the motor wires. The power is supplied through a single voltage and the key makes the connections at the motor terminals, reducing the starting current during start-up. After a time stipulated and adjusted in the switch, the nominal voltage takes effect. This switch provides a reduction in the starting current of approximately 33% of its direct starting value. It is used almost exclusively for empty (unloaded) machine starts and is suitable for machines with resistant starting torque up to 1/3 of the nominal torque.

The load resistant torque must not exceed the motor starting torque, nor must the current at the moment of switching reach very high values. The high resistant torque causes the motor to accelerate to 85% of the rated speed when the starter is switched. At this point, the current, which was approximately equal to the nominal, goes to 320%, which has no advantage, since the current was 190%. 

In the star connection, the motor accelerates up to 95% of the rated speed and at that point the current is at 50%. Then switching takes place and the current rises to 170%, that is, practically equal to the star inrush current. The motor speed generally stabilizes between 75% and 85% of the rated speed. The passage from the star connection (higher voltage) to the triangle connection (operating voltage) is controlled by a timer installed on the switch, which works with a delay of 30 to 100 ms (milliseconds) in order to avoid a short circuit. between phases, since the contactors cannot be closed simultaneously.

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ANALOPG VOLTMETER
MEDIÇÃO

É utilizado para medir a diferença de potencial entre dois pontos

DATASHEET

ANALOG ANMETER
MEDIÇÃO

O amperímetro é um instrumento utilizado para fazer a medida da intensidade no fluxo da corrente elétrica que passa através da seção transversal de um condutor.

DATASHEET

CURRENT TRANSFORMER
MEDIÇÃO

A função do transformador de corrente é reduzir uma corrente medida na alta tensão a um valor muito menor

DATASHEET

CABLE GLAND
CONEXÕES

A linha de prensa-cabos da Lombard foi desenvolvida para proteger a sua instalação elétrica com segurança, evitando perdas de energia.

DATASHEET

 

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