Why Does My Generator Run, but Not Produce Electricity? Flashing the Field, AVR and Brush Holder Replacement

 

Loss of Residual Magnetism (Most Common)

Generators work by moving electrical conductors through a self-created magnetic field. However, generators do not contain any magnets. The magnetic field referred to is created by taking some of the generator output voltage, converting it to DC, and feeding it into a coil to make an electromagnet.

Generators start up by using something called residual magnetism. This is a small amount of magnetism left over from the magnetic field that was created the last time the generator was running. This little bit of leftover magnetism is enough to produce a small amount of electricity. This small amount is used to create an electromagnet. As the engine begins to turn this electromagnet, moving its electric field, through the stator windings, your generator will produce more power. However, if residual magnetism is lost, your generator will produce no power at startup.

Loss of residual magnetism may be caused by the generation being out of use for a while, having a connected load when the generator is shut off, running your generator for too long with no load, or if your generator is new, it could have lost residual magnetism from long distance transportation vibration.

You can combat loss of residual magnetism by always running your generator with a load and disconnecting that load before you turn the generator off. There are ways to regain residual magnetism if it is lost

Solution : Flashing the Field

• Battery Method
  
  To restore the small amount of residual magnetism necessary to begin voltage buildup, connect a12 volt battery to the exciter field while the generator is at rest, as follows:

1. Remove exciter field leads F+ and F- from the voltage regulator. CAUTION: Failure to remove the field leads from the regulator during flashing procedures may destroy the regulator.
2. Measure the exciter field resistance from the F+ to the F- lead. You should be able to read some resistance as you are measuring a continuous winding. An infinite resistance reading would indicate an open in the exciter field. Also check to be sure there is no path to ground.
3. Connect F+ to the positive pole of the battery.
4. Hold the F- lead by the insulated portion of the lead wire, touch F- to the negative pole of the battery for about 5 to 10 seconds, then remove.
5. Reconnect F+ and F- to the regulator. Repeat the procedure if the generator fails to build voltage.

• Drill Method
  
  If you’re caught in a power outage and your generator is not producing electricity or not starting, it might amaze you what a corded and cordless drill could do for you. Though these small tools can yield some magic to save the day, they aren’t necessarily the safest to use by any means.
  
  When a generator is lacking residual magnetism in the alternator, a corded drill can certainly be used with relative safety to “flash the field” and give the alternator the push it needs to start generating electricity.
  
  Over time, magnets inside the generator lose their charge and they are not excited enough to get started. The engine will work fine, but you will not get any power.
  
  So the strategy is to take a ½” corded drill and plug it in and follow the steps mentioned below.
  

• Hold down the trigger.
• Now twist the chuck backward by sticking something in it. We are sending the electricity into the generator to make it excited enough to generate power.
• Start the generator and try this method.
• Your drill must have permanent magnets otherwise this trick won’t work.
• Be very careful when you stick something in the chuck to twist it backward. When the generator kicks on, the drill will tangle you up.
  
  The drilling method doesn’t always work but flashing a generator with a battery always works. I don’t even remember how many times I have used this method to power my generator.
  
  When your unit is generating power again, keep it running for at least 5 minutes otherwise, it will lose magnetism again.
  
  

Video : 

 

Test and Replacing AVR

You know firsthand that a malfunctioning AVR could cause permanent damage to your generator. That’s especially true if you didn’t sort it out as soon as possible. Here are the steps you need to take to determine if your AVR is okay or not.

• Check the voltage from the input pin to the ground.
• Test the voltage going into the voltage regulator. Take your multimeter and insert it in the DC voltage setting.
• Take the probes and insert the positive on the input of the AVR and the negative on the ground pin.
• The AVR is receiving enough voltage to regulate down if you see a higher voltage reading.
• If the regulator is rated to the output of 5V, you should read a voltage close to 5V coming out from the output.
• To measure the output voltage, put your multimeter set in the DC voltage and place the positive probe on the output pin of the AVR. The negative probe on the regulator’s ground pin.
• You should now read a voltage at or about the rated voltage the AVR is designed for.

Video

Test and Replacing Brush Holders

Test and Replacing Breakers