A power relay is a device that can produce a jump in one or more electrical output circuits when the input (or excitation) meets certain prescribed conditions, and can be used in a neutral point directly grounded system, as The directional element of zero sequence current protection. It has a wide range of applications. Today we will talk about the application and working principle of Omron's small power relays.
Power relays are often used in home appliance applications such as air conditioners. The more common ones are OMRON's G4A type and so on. In recent years, the rapid development of high-power household appliances, such as electric water heaters, drinking fountains, etc. all use this type of relay.
1. Rated operating voltage or rated operating current: This refers to the voltage or current required by the coil during high-power operation. The structure of one model is roughly the same. In order to adapt to circuit applications of different voltages, one type of large usually has multiple rated operating voltages or rated operating currents, and they are distinguished by specifications.
2. DC resistance: This refers to the DC resistance of the coil. In some product manuals, the rated working voltage and DC resistance are given. At this time, the rated working current can be obtained according to Ohm's law. If the rated working current and DC resistance are known, the rated working voltage can also be obtained.
3. Pull-in current: It refers to the smallest current that a small high-power relay can produce a pull-in action. In actual use, in order to make small high-power relays reliable pull-in, the given voltage can be equal to or slightly higher than the rated working voltage. Generally, it should not be greater than 1.5 times the rated working voltage. Otherwise, the coil will be burnt.
4. Release current: It refers to the maximum current generated by the small high-power relay to release the action. If the current of the small high-power relay in the pull-in state is reduced, when the current is reduced to a certain level, the small high-power relay returns to the state when it is not energized. This process is called the release action of the small high-power relay. The release current is much smaller than the pull-in current.
5. Load: It refers to the voltage or current allowed by the contacts of a small high-power relay. It determines the size of the small high-power relay that can control the voltage and current. In applications, small high-power relays with small contact loads cannot be used to control large currents or high voltages. For example: the contact load of Y3F small high-power relay is 0.02A×12V, so it cannot be used to control the on-off of 220V circuit.
The above content is Saddle Point’s answer about relays this time, I hope it will be helpful to everyone.