Over Voltage Protection
Over Voltage Protection
When the voltage in the circuit is raised above its upper design limit, this is known as overvoltage. Depending on its duration, the overvoltage event can be transient voltage spike, surge or permanent high voltage.
Source:
These abnormal over voltages may be caused due to various reason such as, sudden interruption of heavy load, lightening impulses, switching impulses, insulation failure etc.
These over voltages hardly cross the twice of the normal voltage level. If over voltage protection is not provided to the power system, there may be high chance of severe damage.
For example an electric light bulb has a wire in it that at the given rated voltage will carry a current just large enough for the wire to get very hot, but not hot enough for it to melt. The amount of current in a circuit depends on the voltage supplied: if the voltage is too high, then the wire may melt and the light bulb would have "burned out". Similarly other electrical devices may stop working, or may even burst into flames if an overvoltage is delivered to the circuit.
General Conditions:
An international voltage standard for 3-phase 4-wire LV systems is recommended by the IEC 60038 to be 230/400 V.
Kindly find the below table showing the different voltage ranges in different countries:
Dedicated supply lines at LV are generally applied (at 220/380 V to 240/415 V) to a load range of 80 kVA to 250 kVA.
Consumers normally supplied at low voltage include:
a) Residential dwellings
b) Shops and commercial buildings
c) Small factories, workshops and filling stations
d) Restaurants
e) Farms, etc.
Requirement of OverVoltage Protection:
The requirements on the switched mode power supply applications regarding the input AC voltage range are constantly increasing: for example, the ultra wide input voltage range of 90 to 440 VAC is now commonly required in many applications (electricity meters, lighting, factory automation). To fulfill the current market need, we have incorporated the feature of 440VAC input voltage protection for more than half an hour.