Description
Motor protection is provided by the thermal-magnetic protection elements incorporated in the motor circuit-breaker.
The magnetic elements (short-circuit protection) have a non-adjustable tripping threshold, which is equal to 13 times the maximum setting current of the thermal trips.
The thermal elements (overload protection) include automatic compensation for ambient temperature variations.The rated operational current of the motor is displayed by means of a graduated knob 4.Personnel protection is also provided. All live parts are protected against direct finger contact from the front panel.
The addition of an undervoltage trip allows the circuit-breaker to be de-energised in the event of an undervoltage condition. The user is therefore protected against sudden starting of the machine when normal voltage is restored, since the Start button “I” has to be pressed to restart the motor.
With the addition of a shunt trip, de-energisation of the unit can be remotely controlled.The operators on both open-mounted and enclosed motor circuit-breakers can be locked in the Stop position “O” by up to 4 padlocks.
Because they are suitable for isolation, these circuit-breakers, in the open position, provide an adequate isolation distance and indicate the actual position of the moving contacts by the position of the operators.
