The selection of the toggle switch cannot be arbitrary. Its carrying capacity is one of the core considerations. In most cases, we will choose a high current toggle switch. The reason is quite simple:
1. The current at the moment of equipment startup is much greater than the rated current. For ordinary electrical appliances, the working current is 5A, and the startup surge current may reach 15-30A. Small current switches cannot withstand surges and startup surges, and are prone to be contact burnout, switch overheating and occasional malfunction. While the contacts of high current switches are thicker and the spring clips are stronger, inherently resistant to surges and arc.
2. In long-term full-load operation, small switches cannot withstand it. Motors, oil pumps, relays, and lamps all belong to inductive loads. Switching on and off will generate arc sparks.
①Small current switches: Arcs are prone to burning the contacts, and they will fail after a few hundred or thousands of times of use.
②Large current switches: Silver alloy large contacts have strong arc extinguishing capabilities, and the lifespan is directly several times longer.
3. Leaving sufficient margin means not burning the equipment and avoiding after-sales issues. General principles for electrical engineers' selection: The rated current of the switch ≥ 1.5-2 times of the actual working current. For example, if the equipment actually uses 8A, a 15A/20A high-current switch must be selected. If a 8A small switch is selected, in summer with high temperatures and line voltage drop, it will definitely heat up and fail.
4. High-current toggle switches have better materials and more durable structures. The high current models generally come with: Thicker silver alloy contacts, thicker conductive copper sheets, more stable terminals (screw terminals / large solder tabs), higher flame-retardant grade and better sealing of the casing. Their durability, waterproof, anti-vibration, and anti-aging are much stronger than those of small current models by a large margin.