Generator Output Voltage Too Low – How Do I Increase It?

c. How do I increase the voltage of my generator

Low Generator Output Voltage 

With an increasing demand for electricity, generators are gaining popularity, and almost every home, school, and office now has at least one generator in their possession. One common problem that almost every generator user faces very often is a drop in voltage.

This is dangerous because low voltage supply is one of the leading causes of electrical devices getting overheated. When the voltage is low, the motor in electric appliances is forced to draw more current to be able to deliver the same magnitude of electric power.

Learning how to fix low voltage can help you save your expensive generator from irreparable damage. This article will explain the common causes of low voltages and at the same time give you some tips on how to fix it.

Why is my generator not producing power(Quick ways to fix it)?

causes of under voltage

Load Exceeding the Operating Capacity of Generator

There are many causes of the drop in voltages. One very common cause is that the load applied to the generator is greater than its operating capacity. This causes the generator to either slow down or completely drop voltage, in turn affecting everything that is connected. In some cases, it can cause permanent damage to the generator as well as the devices connected to it.

It is not a technical fault and can be easily fixed just by making sure that a load of connected devices is not exceeding the capacity of your generator.

Some Mechanical Issues

Sometimes the generator turbo is unable to provide sufficient air and high pressure the generator needs to operate at its full capacity. Moreover, often there is some clogging of the fuel filters or fuel tank that hinders the smooth supply of fuel to the generator. Lack of consistent and adequate fuel supply also causes the voltage to drop.

These common mechanical issues are not too serious and can be easily resolved by calling a professional

A Damaged Circuit Breaker 

A circuit breaker is one of the most important things that you must check when a generator is producing low output. To explain it in simplistic terms, a circuit breaker is installed for the safety of your devices. It is designed in such a way that it automatically switches off the generator whenever the voltage is too high. However, when damaged, a circuit breaker may unnecessarily reduce the power supply and cause low voltages.

What happens if voltage is too low

In that case, you may need to check the position of the breaker and measure the resistance inside the electrical panel as well as on the lead wire connections. You can do this using a multimeter and a normal reading would suggest that the breaker is working properly. If the meter shows overload, then you may have to seek professional help, get it checked properly, or simply replace it. 

A Dysfunctional Capacitor 

A drop in voltage can often indicate that there is something wrong with the capacitor because it is responsible for inducing as well as regulating the voltage. If you have some basic knowledge of how electric devices work, then you can easily test the capacitor using a multimeter.

First, you need to remove the capacitor from the generator and then discharge it with the help of a screwdriver that has an insulated handle. After it is discharged, the next step is to note the reading on it which must be +/-5uF of the rating that is mentioned on it.

Anything more or less will indicate that the capacitor needs to be repaired or ideally replaced. 

Try Field Flashing the Alternator 

 Another important part of the generator is called an alternator which is responsible for charging the capacitor using the residual magnetism present in the windings. When a generator is not used for a long time, then the residual magnetism may not be high enough to build up the terminal voltage that is needed to charge the capacitor.

To deal with this, you will have to connect an external DC source to the field winding. This will help build up voltage and hence help charge the capacitor which can be then reinstalled into the generator. The process is commonly known to electric experts as field flashing.    

Damaged Windings of the Stator 

In a generator, the magnetically charged rotor rotates inside the part called a stator. A low voltage may often be caused by some problem with this part. It should be noted that there are two types of stators- brushed and brushless – and both work differently. Moreover, stators are very complicated and you need expert knowledge as well as information from the manufacturer to test them.

The most you can do at home is to determine if there is any broken circuit within the stator winding or test its resistance using a multimeter connected to each end of the wire coil. The reading for resistance that you obtain must match the specifications provided by the manufacturer.

Anything different from it will indicate that there is some problem with the windings or maybe something even more. 

Automatic Voltage Regulator

The AVR plays a very crucial role in the working of a generator. It is basically a circuit that is responsible for regulating the output voltage.

You can find out if your AVR has any problem by testing the generator’s main circuit breaker. If you find nothing wrong there, then the next thing you can do is to test all the wiring. If there is nothing wrong with that either, then maybe you can fix your generator simply by ensuring that your AVR is not out of adjustment.

Moreover, in some cases, you may also have to check the rotor brushes to find out if they are in working condition.

If none of this helps, then either your stator is not producing power or your AVR needs to be replaced. 


This article has provided you with some of the most common causes of low voltage and explained some of the ways you can try fixing it to increase the voltage of your generator. These tips may sound simple but these parts need to be handled with a lot of care. If you do not have sufficient knowledge of electric devices, then it is better to seek professional help. 

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