Explain some symbols on contactor

On each contactor, there are descriptions of specifications. Certainly, not everyone understands these symbols. Hao Phuong will help you understand some specific symbols on the contactor through this article.

According to IEC 60947-5-1 standard of the contactor, there are symbols on the following meanings

Used for AC loading

AC1: Used for pure resistive loads such as drying resistors. The contactor’s main contacts are selected to close the loads with non-larger Cos greater than 0.95. This type applies to all AC loads with a Cos factor of over 95%.

AC2: Used for switching of an asynchronous motor rotor winding load, starting the brake release, reverse brake. The main contacts of the contactor when closed the circuit bear a load of about 2.5 times the rated current of the motor.

AC3: Used for switching of the motor dynamic load of the squirrel cage rotor. The load bearing point when starting is 5-7 times the rated current of the motor. Commonly used for star/delta starter, crane circuits.

AC4: For shocking cage rotor motor load, reverse brake, release, reverse rotation.

Used for DC loading

DC2: Used for parallel DC excitation motors. When operating the time constant of a load of about 7.5ms the main contacts close it with a current of about 2.5 times the rated current of the motor.

DC3: Used for DC motor with excitation, reverse working, reverse braking, load circuit time constant is less than 2ms. The main contacts bear the starting current valued at about 2.5 times the rated current of the motor.

DC4: Used to disconnect the DC-excitation DC motor load circuit when the motor is operating normally, the load time constant is about 10ms the main contacts bear the starting current of about 2.5 times the rated current engine level.

The parameters on each firm have different symbols for example:

Schneider: LC1 D09, LC1F115 …

ABB: AX12-30-10, AF370-30-11 …

It means that the contactor is used for small cosphi coefficients such as the inductance of the motor with the numbers 09,50,75,12,95, which is the Parameter printed line of AC3.

Ith: Is the maximum flow of contactor when used with a load capacity of 0.85 to 0.95 and above and it is AC1 type

Ui: is the insulation voltage of Contactor

Uimp: insulation impulse voltage

After this article, there will be many people who understand the parameters on the contactor.

Customers interested in contactor please contact us for the best support via Hotline: 1800 6547 or email: cs.@Haophuong.com