Electrical protection switch with automatic or manual operation

摘要

The contactor has a housing (1) which contains a main current loop with one or more movable contacts (4). The housing (1) also contains terminal clamps for the current loop and an electromagnetic drive (5). An armature of the drive (5) actuates a mechanism (9) between the drive (5) and the movable contact(s) (4) to actuate them when the drive is actuated by transmission of a signal and to open them again when no current flows. A control loop supplies the electromagnetic drive (5) with a low resistance which is normally short circuited by a movable auxiliary contact and which is connected in series with the electromagnetic drive (5), when the auxiliary contact is actuated. A hand switch (18) is manually adjusted to an automatic operation position where the main contacts are actuated by a mains transmitted signal and are released again at the end of the signal. The hand switch (18) also has a forced operation position where the switch moves the mechanism back to the operating position and holds it there. With a control signal, when the switch is in forced operation mode, activation of the electromagnetic drive causes actuation of the auxiliary contacts to set the resistance in series with the drive and to trigger the hand switch (18). The latter is then returned to automatic operation to act through a pick up device. The mechanism (9) of the main contact is arranged such that it is directly actuated by the hand switch (18) when this is pushed to its forced operation position while the armature of the electromagnetic drive is scarcely or not at all effected by the switch when it is in this position. The pick up device (22) of the hand switch (18) can be released after substantial movement of the armature.