What Happens If the Voltage is too High?

High voltage in an electrical circuit is always dangerous and should be avoided. But sometimes overvoltages occur and we should be aware of its consequences. Based on my experiences and research, I listed all the effects of overvoltage for you.

Effects of Overvoltage

Overvoltage effects on end-use can be the following:

1. Faulty operation

High voltage is harmful to electrical devices and systems. For example, high voltage can cause inefficient illumination of lights. It also can affect the efficiency of electrical machinery.

When the voltage supplied to a light bulb exceeds its rated voltage, the bulb will consume more energy and generate more heat which can cause the filament to burn out more quickly. This will lead to inefficient illumination and a shorter lifespan of the bulb.

When high voltage is supplied to electrical machinery, it can cause the machinery to overheat which can damage the insulation on wires and other components. This can lead to short circuits, equipment failure and even fire.

inefficient illumination of lights — *Faulty operation*

2. Damage to the PCBs

Overvoltages can damage components and circuit boards. It can burn or destroy the equipment. Even worse it could start a fire.

When voltage levels exceed the safe limits of the equipment, it can lead to overheating, burning and even explosions in extreme cases. The excess voltage can cause the components to draw more current than they can handle, which can result in overheating and failure.

Damage in the PCBs — *Damage to the PCBs*

3. Tripping of sensitive loads

The high voltage could stop the operation of critical equipment. For example, an uninterruptible power supply (UPS) can trip or burn.

This is because many electronic devices and electrical systems have specific voltage requirements, and if the voltage supplied to them exceeds their limit, it can cause damage or failure to the equipment.

UPS trip — *Tripping of sensitive loads*

4. Overheating

Damage to an electronic component is the potential and direct effect of overheating. This is especially true if the component is unable to withstand excessive levels of heat. Note that most failures in electrical and electronic components are commonly associated with overheating and subsequent burning.

5. Increase in power consumption

Overvoltage can increase your energy bill. In a domestic installation with electric hot water, cooking and reverse cycle air conditioning, a sustained 5% overvoltage could be expected to have a high energy cost.

When the voltage supplied to electrical equipment is higher than the rated voltage, the equipment may draw more current than required, resulting in higher energy consumption. This increased energy consumption will lead to higher energy bills over time.

6. Internal damage to the conductors

Electromigration decreases the reliability of integrated circuits. It can cause the eventual loss of connections or failure of a circuit. Since reliability is critically important for electrical installations, overvoltage is a major focus of research efforts.

7. Unnecessary tripping of downstream circuit breakers

A circuit breaker shuts off the electrical flow to protect the circuit from overheating. It’s a safeguard that helps prevent damage and electrical fires. If it happens often, there’s a root cause that you need to address. One cause of a tripped circuit breaker in the downstream circuit is overvoltage.

Tripping of circuit breakers — *Unnecessary tripping of downstream circuit breakers*

8. Malfunction and shutdown

There are many causes of malfunction and shutdown in an electricity network. Examples of these causes include a short circuit, cascading failure and high voltage.

9. Short lifespan

When an overvoltage occurs, the life of the component will be decreased and it will probably cause a permanent failure in the loads.

Therefore, it’s important to ensure that electronic devices and components are protected from overvoltage by using appropriate surge protection devices and voltage regulators.

10. High starting current in motors

The starting and full load current will also be affected by overvoltage. At 110% voltage, the starting current will go up by 10-12%. This would be a problem if the power supply cannot handle the higher starting current.

electrical motors — *High starting current in motors*

11. Extra costs and errors

Data loss + Damage to internal equipment such as fire and security systems + Extra costs to any business such as lost productivity and product spoilage, staff overtime, delays to customers and sales lost to competitors.

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