Dead Gennie --- What to do???

[MtnTopRebel]

A few days ago, we had some strange happenings in our electrical system.  An electrical storm was still some 15 to 20 miles out, and we were getting ready to shut down our equipment.  My wife was running her computer, and said she had a loud pop by here computer, I told her to shut things down, but before I could get out to the power shack, seven more surge protectors popped off. I bolted out the door, hit the kill switch on 2436 Trace inverter, the generator, which is a China Diesel with a 12 KW coupled 220 Volt gen attached, (Brush unit with 4 brushes two per slip ring)loaded down strangly when I did, like it received a heavy load. I hit the breaker for the gen, and shut down the engine.  We waited till the storm had clearly passed before I turned on the inverter, which provided the power for the rest of the evening.  Next morning I fired up the diesel to charge and run the pump, but got zero output out of the gen.  I thought well the bridge rectifier failed, so went to town and bought a new one and installed it, but still nothing.  I checked for voltage to the rectifiers, and am getting nothing.  I tried to excite the winding by applying a spark of 12 v. dc. to the  winding, but still nothing....  Does anybody have a suggestion?  Also, I might add, I do have the power panel grounded.  I did find, that an external modem had been still connected to the phone lines fried, and since it had its own power supply probably returned the arc to the AC even though the computer was off via a switch panel so was isolated from the AC.  People here have had a lot of problems with lightning through the phone lines... anyway, I'm dead in the water and don't know what to look for.  Brushes, and the brush wires look fine, I can find no visible problem, and don't know what to test for what, to figure this out...  Thanks!

[GeoJohn]

I am no expert on generators, but someone once told me. "Just because you see worms on the ground after it rained does not mean it rained worms."

My corrollary: "Just because your system died when there was an electrical storm 15 miles away does not mean the storm killed it.

That your surge protectors tripped suggests to me that the generator or inverter went into serious overvoltage mode and the surge protectors possibly saved your electronics. Lightning through the phone lines is unlikely to screw up anything other than the phones. I think your generator blew.

[niffa]

Hi,

I would check the gen winding resistance to see if you have fried the windings (most likly stator windings). If you have low resistace to earth (case) and/or one winding different to others a rewind may be required. Be sure to isolate the generator from all power supplies before testing.

[OPEC BUSTER]

I think you may need to use a megometer to check the stator windings, an ohm meter may not show a possible short in the windings. I also would give a good look at my grounding system, it is most likely insuficient! GOOD LUCK!

Otis

[georgeodjungle]

if it was lighting,

to many grounds to far a part will allso act like that.

don't get me wrong grounds are good.

lucky that's all that went.

i'd say windings to.

[wpowokal]

Two things come to mind, you say the genie loaded down when you turned off the inverter.

Do you have an automatic charger that could account for this, that is loss of volts at the inverter triggering it.

Also if generators are shut down under load they can demagnitise themselves, you appear to have twigged to this. How long is a spark, you need to apply the 12v to the posotive and negative (that is DC side) of the bridge.

10-15 seconds is no problem.

allan down under

[jimjjnn]

Allan, I think you hit it right on the nose. If gens are shut down with any kind of load, no matter how small, The armature will demagnetize.

[techwolf]

Are you grid tied with this setup? if not how can the power surge from a strike get into your system? I dont see how the genset could be fried by the phoneline.

is there any voltage at the sliprings when the gen is running? do you know which ring is plus or neg.

[veewee77]

Actually, lightning through the phone lines can screw things up.  I have worked on a computer that took a lightning strike through the modem and it actually fried the monitor that was connected to that computer, as well as the modem. Put on a new monitor and modem and it worked fine, (for awhile, then the mobo died).

Also, I have seem phone line strikes fry other things in the house as well.  Computer modem fried and so was the microwave at one place.  An alarm clock at another. And BTW those $5 wal-mart fall-apart alarm clock radios survive usually when nothing else does. But that one fried along with the modem in the computer. . .

Best thing when there is lightning nearby is to disconnect everything that leaves the building or connects between buildings.

Been there, done that. . .

Doug

[MtnTopRebel]

Thanks for the response, I will try the 12v spark to the +/- of the bridge... I was sparking blind before.

with a digital volt meter on the ~ ~ contacts there was no voltage whatso ever.

the ground is 5 feet from the control panel with 2 #12 Ga wires running from the common ground of the box to the rod.  (a friend suggested I eliminate any ground, he hasn't had any problems since doing it)

as for the phone lines, I work on computers, a neighbor a couple years ago, had a HV spike come through her phone line, it blew the cube tap out of the wall melted the (RJ11) socket and blew the insulation off the phone cord for nearly 40 feet.  Her surge protector for the phone line saved the day.  (her phone line is underground for miles... don't figure)but she is just one of a dozen I can recall.

I will give your suggestions a test, thanx Mtn

 

[Experimental]

      DON,T eliminate your grounds -- you would be risking serious electrical shock and things like Ground fault interupters, won,t work !!!

      Those grounds are there, to take "stray" currant away and doubtful, that it had anything to do with your generator..

      Many inverters, however, can,t tolerate the neutral being bonded to ground and you will see the "magic smoke" if you hook these to a bonded box !!

      Sounds like your gen, suffered from being shut down, under load , and you are already on your way to remedy, of that situation !!

      Good luck to you, but for the safety of you and your family, keep things grounded !!  Bill H......

[wdyasq]

hey there, this is jacquesm posting from RonB's house

do you have a make & model for that generator ? Possibly a schematic (mine has a

full schematic printed in the back of the owners manual). That would make it a

lot easier to figure out what's up. Be careful with applying DC to your windings

without knowledge of how high the voltage should be, that might make matters worse.

It's most likely electronics, not copper that are the problem. Look for floating fuses

(inline fuses in little holders), check all of those first (and any other fuses or

breakers that you can find).

j.