dc power relay off state

In addition to ensuring reliable arc extinguishing, the distance between the dc power relay contacts when the dc power relay is disconnected should also be able to withstand sufficient circuit voltage without being broken down, that is, the dc power relay contacts must have sufficient dielectric strength, which is necessary for the dc power relay contacts to be disconnected. The most important requirement in the state. For this reason, a voltage much higher than the rated voltage is usually specified (taking into account the possible overvoltage of the line) to test the electrical appliance as a standard to measure its dielectric strength. Under the action of this voltage, the dc power relay contact gap should be guaranteed not to be broken down and no other flashover phenomenon (this requirement is required between all disconnected conductive parts and between the conductive parts and the ground). This voltage is called the test voltage. For example, for a DC electromagnetic dc power relay with a rated voltage of less than 20 volts, the test voltage is specified as 10 volts (0 Hz AC RMS, action time is 1 minute).

Of course, the size of the dc power relay contact gap should also be considered during use, the surface of the dc power relay contact will gradually form needle-like protrusions, the dc power relay contact reed may be deformed, or the dc power relay contact may bounce to the final position, which may reduce the gap. Small and other factors to ensure proper margin, so that the dc power relay contacts work reliably.