I excited field with a 12v battery , but after reading others solutions , not sure if it should be done with 12v dc or 12v ac . could the capacitor be bad ? or what really goes bad with generators that makes them quit putting out voltage?
heres how i fixed it . all thats inside the field end is 2 diodes and a capacitor . called powermate 1-800 # on the generator and the nice woman there gave me the resistance values of field , stator and the magneto . after checking them and found that they were ok , i checked the diodes and capacitor . the capacitor was the problem . i ordered the cap. from the nice woman in nebraska for 9 dollars and some change + 10 dollars shipping . when i got it i checked cap. before i put it in i excited the field and it started generating power again . i will add that when i excited the field this time , the stator actually rotated about an 1/8 inch . im glad it worked . and thank you for verifying ac or dc voltage . heres how i fixed it . all thats inside the field end is 2 diodes and a capacitor . called powermate 1-800 # on the generator and the nice woman there gave me the resistance values of field , stator and the magneto . after checking them and found that they were ok , i checked the diodes and capacitor . the capacitor was the problem . i ordered the cap. from the nice woman in nebraska for 9 dollars and some change + 10 dollars shipping . when i got it i checked cap. before i put it in i excited the field and it started generating power again . i will add that when i excited the field this time , the stator actually rotated about an 1/8 inch . im glad it worked . and thank you for verifying ac or dc voltage .
AnonymousMar 28, 2014
Have checked all coils for continuity...ok. Checked the capacitor on the exciter coil...ok Checked the diode on the end of the armature...ok. checked the armature coil for continuity...ok. Remagnitized via the field coil using a 12V battery and an ac system found on the web. Still no power being generated. lHave checked all coils for continuity...ok. Checked the capacitor on the exciter coil...ok
Checked the diode on the end of the armature...ok. checked the armature coil for continuity...ok. Remagnitized via the field coil using a 12V battery and an ac system found on the web. Still no power being generated.
l
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Most of the time it is either the Capacitor or AVR that has blown. Check out our videos on how to test them.
We hold a full range of Generator AVRs and Capacitors. https://www.generatorguru.com
If you need help testing let us know. We have a whole Help Center dedicated to helping people fix their Portable Generators. Check it out on our site. https://www.generatorguru.com/
Disconnect the rotor field wires at the AVR or on the exciter/brushes. Note they are polaroty sensitive. Connect a 12V battery to F+ and F- (note polarity) and momentarilly power from the battery for a few seconds. DO NOT forget to disconnect the rotor/exciter field wires first or the voltage regulator will be damaged.
Try flashing the rotor it has lost it's resideual magnetism through sitting.
Disconnect the rotor field wires at the AVR or on the exciter/brushes. Note they are polaroty sensitive. Connect a 12V battery to F+ and F- (note polarity) and momentarilly power from the battery for a few seconds. DO NOT forget to disconnect the rotor/exciter field wires first or the voltage regulator will be damaged.
Disconnect the rotor field wires at the AVR or on the exciter/brushes. Note they are polaroty sensitive. Connect a 12V battery to F+ and F- (note polarity) and momentarilly power from the battery for a few seconds. DO NOT forget to disconnect the rotor/exciter field wires first or the voltage regulator will be damaged.
If it has sat, it may have lost it's rotor residual magnetism. Disconnect the rotor field wires at the AVR or on the exciter/brushes. Note they are polaroty sensitive. Connect a 12V battery to F+ and F- (note polarity) and momentarilly power from the battery for a few seconds. DO NOT forget to disconnect the rotor/exciter field wires first or the voltage regulator will be damaged. If it hasn't sat check voltage regulator, rotor resistance, and stator resistance, and for shorts to ground.
There are a few more components to check in the system. From the information provided this is not a Kohler generator as Kohler makes all their own AC alternators under 350KW, seems you may have just a Kohler engine (probably a CH25). Cannot find any info on the voltage regulator which leads me to believe it may be integrated into the main controller. Curious to know who the manufacturer is. If the capacitors are good, try checking the diodes. A volt/ohm meter with a diode check will do. Voltage reading on one side and nothing on the other. If you have no access to a diode check feature, try reading it through a battery NOT SHORTED TO BATTERY hook a meter to a battery and put the diode between one of the leads to the positive, one way will read voltage the other will read open, no voltage, or OL. Look for any fuses or breakers blown / tripped. 6 VAC on the output is about residual voltage meaning voltage the alternator makes without any help from a voltage regulator or field voltage. This usually means the alternator / rotor windings are still good. This alternator is brushless so you could seperately excite this unit via a 12V battery through your field. Look for your exciter field winding, it should have some kind of label on it saying F+ and F-, apply 12V here momentarily on + & - respectively with the unit running and you should see your output voltage spike. This tests the alternator. If this tests ok, then check to make sure your wiring / fuses from the alternator to the controller or voltage regulator (voltage sensing leads) are ok. If all these check ok, it is likely you have a bad voltage regulator.
If the voltage is less than 20 V AC, you should check the excitation field, rings and brushes, AVR - rectifier, cables and fuses.
If every thing is OK you may need to recharge the DC field with a short connection of "+" and "-" of a 12 V battery to respective field terminals when the engine is running.
If the AC voltage raises for a second and drops when you disconnect the battery - the excitation circuit is bad.
One sure thing is you better find a competent service guy.
It sounds like you have lost excitation to the field of the alternator. Without documentation I can't tell if this is a brushless type or brush type rotor.
In either case, the excitation needs to be restored. On a brushless type, either lack of residual magnetic flux to start the buildup of the field OR failure of the rotating diode(s) can be the problem.
In a brush version, investigate "flashing" the field on Google or trace out why there is no voltage to the field. Possible things for this are failed transformer, failed rectifier, blown protective fuse and or wiring.
Here is a simple test to check field and other wiring. With engine off apply 12v ac 1 amp to 110v outlet plug on generator. This will energize the field windings and should cause the armature to produce dc voltage at the brushes and produce a nice magnet. If there is a short in the field or broken wire or shorted capacitor there will be no dc reading at the brushes. . This test is the opposite of what actually occurs when the engine is running. That is the armature produces a magnet fed thru the windings, regulator and brushes. If dc voltage is present at the burshes, remove 12v ac and start engine to check for output. enjoy
heres how i fixed it . all thats inside the field end is 2 diodes and a capacitor . called powermate 1-800 # on the generator and the nice woman there gave me the resistance values of field , stator and the magneto . after checking them and found that they were ok , i checked the diodes and capacitor . the capacitor was the problem . i ordered the cap. from the nice woman in nebraska for 9 dollars and some change + 10 dollars shipping . when i got it i checked cap. before i put it in i excited the field and it started generating power again . i will add that when i excited the field this time , the stator actually rotated about an 1/8 inch . im glad it worked . and thank you for verifying ac or dc voltage .
Have checked all coils for continuity...ok. Checked the capacitor on the exciter coil...ok
Checked the diode on the end of the armature...ok. checked the armature coil for continuity...ok. Remagnitized via the field coil using a 12V battery and an ac system found on the web. Still no power being generated.
l
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