What does ON mean on an air switch?
3 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.
In the car, the ON position of the air switch means the air conditioning is turned on, the fan starts running, the compressor also kicks in, and it's ready to blow out cold air. I often go out for drives, especially on hot days, and as soon as I turn the AC switch to ON, the car interior cools down quickly. If ON isn't turned on, the AC system stays idle, and no air blows out. It's quite simple to operate—just twist the knob or press a button—but it's best not to get distracted while driving; safety comes first. I've also noticed that if ON is left on for too long, the battery might drain a bit faster, so I usually turn it off when I arrive. Regular checks on the AC system are also important to ensure the condenser pipes and refrigerant are in good condition; otherwise, the cooling effect might be poor when ON is activated. During long summer drives, keeping ON turned on is a must to avoid heatstroke. Every seasonal maintenance, I have the technician check the AC switch to prevent poor contact or other issues, since the whole system is working when ON is activated, and even a minor fault can affect comfort. In short, ON is a pretty basic function—it's what starts the AC—and it's very convenient for daily use.
Turning the air switch to ON activates the car's air conditioning system, which essentially means the system starts working. As someone who DIYs car modifications, I've taken apart several car AC panels. In the ON state, the control circuit is engaged, the compressor wheel spins to compress the refrigerant, and the fan blows cold air from the intake. If you turn it to OFF, everything shuts down. In practice, many people mistakenly think that just turning ON the AC is enough, but you also need to set the temperature and fan speed, otherwise the performance won't be optimal. I also recommend regularly checking the AC's fuses and relays—if there's no response when you turn it ON, these components might be blown. Another key point: when ON is activated, the engine load increases, leading to slightly higher fuel consumption, so be mindful during frequent city stop-and-go driving. Cleaning the AC filter is also crucial; if the filter is dirty, even ON operation won't deliver good air quality. Overall, ON is just a switch position, and understanding the principle makes operation straightforward.
