1. The rated voltage is the guarantee of the reliability of the relay. Although the relay can work when the coil voltage exceeds the operating voltage, it will operate by mistake under strong impact. Coil voltage exceeding the maximum operating voltage will cause coil insulation drop, interturn short circuit, burning loss.
2. The coil resistance value of the relay will change by 0.4[%] per ℃ due to the change of ambient temperature and the heat of the relay itself. Therefore, if the coil temperature rises, the operating voltage and disconnected voltage will also increase. Automobile relays are driven by batteries, and the service life of the relays will be affected because the voltage of the power supply will be reduced when the heavy load is connected.
3. The maximum continuous applied voltage of the coil: the maximum continuous applied voltage of the coil is mainly limited by the insulation performance of the enameled wire, in addition to affecting the stability of the relay operation. The insulation grade of the enameled wire of the product should be understood. When the ambient temperature of class F insulation is 40℃ in practical use, the maximum temperature rise limit of 115℃ can be considered.