What does ON mean on an air switch?
1 Answers
ON on an air switch indicates connection, while OFF indicates disconnection. The air switch is a crucial electrical device in low-voltage distribution networks and power drive systems, integrating control and multiple protection functions. In addition to completing circuit connection and disconnection, it can also protect against short circuits, severe overloads, and under-voltage in circuits or electrical equipment. It can also be used for infrequent motor starting. Below is an introduction to the air switch: 1. Working principle: When a general overload occurs in the circuit, the overload current may not trigger the electromagnetic release, but it can generate heat in the thermal element, causing the bimetallic strip to bend upward due to heat. This pushes the lever to disengage the hook from the latch, separating the main contacts and cutting off the power. In the event of a short circuit or severe overload current, the short-circuit current exceeds the instantaneous trip setting value, and the electromagnetic release generates sufficient force to attract the armature and strike the lever. This causes the hook to rotate upward around the pivot seat and disengage from the latch. Under the action of the reaction spring, the latch separates the three main contacts, cutting off the power. 2. Main functions: Under normal conditions, the armature of the overcurrent release is released. In the event of a severe overload or short circuit, the coil connected in series with the main circuit generates a strong electromagnetic force to pull the armature downward and push the latch hook open, disconnecting the main contacts. The under-voltage release works in the opposite way. Under normal voltage, the electromagnetic force holds the armature, allowing the main contacts to close. If the voltage drops severely or is cut off, the armature is released, and the main contacts open. When the power voltage returns to normal, the switch must be reclosed to resume operation, achieving under-voltage protection.
