How to excite a 3 phase generator

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Single phase generators usually operate efficiently throughout however, they tend to experience a power dip after some time. The three phase generators on the other hand, don’t experience power dips however, you may need to excite them once in a while.

Three phase generators basically produce separate alternating current waves throughout in order for them to operate efficiently. Well, this alternating current power travels in a sequence which enables the generator to have continuous flow of energy. This consistent flow of energy is exactly what enables the three phase generator to run efficiently throughout without a dip in power. In addition to this, it also enables the three phase generator to be more powerful than single phase generators. Therefore, three phase generators are more ideal for use in large business premises and factories as they produce a lot of power consistently.

There are certain situations when your three phase generator will lose its residual magnetism. This will hinder it from starting up therefore, you will be required to excite it. You can easily excite the alternator of your three phase generator by using a 12V battery.

Steps to follow in order to excite a three phase generator

Locate the exciter field leads

First of all, you should open the Automatic Voltage Regulator cover which is located at the back of the alternator. Once you have done this, you should then locate the exciter field leads F1 (red wire) and F2 (white wire).

Connect the exciter field leads to the battery

You are then required to connect the F1 and F2 exciter field leads to a 12 Volt battery. However, you should be careful when connecting these exciter field leads so that you don’t confuse them. The good news is that connecting these field leads is pretty simple. All you have to do is connect the F1 field lead to the positive terminal of the battery and the F2 field lead to the negative terminal of the battery. It is also important to note that this should be done when the generator is completely off in order to avoid cases of you getting shocked.

Leave them connected to the 12V battery

Once you have rightfully connected the exciter field leads to the battery, let them stay connected for about 30 seconds. After doing this, you should remove them and plug them back in to the Automatic Voltage regulator. You can also test the voltage of the battery in your three phase generator using a voltmeter.

Switch on the generator

After you have gone through all this processes successfully, you should then switch on the generator. At this point your three phase generator will be able to produce power once it’s running because the alternator will have recharged.

What makes your three phase generator lose its residual magnetism?

When you don’t use you generator for a long time

For sure, three phase generators are ideal for use in large business premises. This is because they can efficiently provide power to a large number of electric appliances that have been plugged in to it. However, it is also important to note that these three phase generators require constant electric load from the plugged in appliances in order to run efficiently throughout. This allows them to retain their residual magnetism which comes in handy especially when you start up the generator the next time you use it.

In addition to this, frequently running your three phase generator on constant electric load will enable it to create a strong magnetic field throughout its operation. Therefore, your three phase generator will lose its residual magnetism if you don’t frequently run it on electric load. Unfortunately, this will also hinder your generator from producing power to the plugged in appliances and even starting up.

You should always ensure that you run your generator once in a while even if you don’t use it on a frequent basis so that it retain its residual magnetism. In addition to this, you should also always make sure that you first switch off the generator before you unplug the appliances connected to it.

When you reverse the exciter stator magnetic field while flashing with a battery

For sure, there can be a number of things that you do right with your three phase generator which enables it to run smoothly throughout. However, you should always be careful when flashing the exciter stator magnetic field with a 12V battery. This is because your generator will lose its residual magnetism when you reverse the terminals of the exciter fields. Unfortunately, this will hinder the generator from starting as the applied current won’t be flowing in the same direction as the residual magnetism.

Once this happens, you will be forced to excite your three phase generator with a 12V battery so that it can be able to start up.

Causes
Preventive measures
When you don’t use your generator for a long time
You should always ensure that you run your generator once in a while in order for it to retain its residual magnetism throughout.
When you reverse the exciter stator magnetic field while flashing with a battery
You should be careful when flashing the exciter stator magnetic field with a 12V battery.

Conclusion

Your three phase generator can fail to start up because it has lost its residual magnetism. Well, residual magnetism is very key when it comes to efficient operation of a generator. Therefore, you should take all the necessary steps to ensure that your generator always retains its residual magnetism. You can easily excite the alternator of your generator by using a 12V battery when it fails to start up as it should. Simply follow the steps that we have listed for you and you will be good to go!

FAQs

How can I differentiate the two exciter field leads on the Automatic voltage regulator?

Well, the F1 exciter field lead is red in colour while the F2 exciter field lead is white in colour.

Is the three phase generator supposed to be off when I excite it?

Yes, you should ensure that the power switch is off. This will enable you to reduce the risk of being shocked when you connect the exciter field leads to the terminals of the 12V battery.