Fried Generator ... what happened? any thoughts?

[zacker01]

Hey All.... I was going to get my Generator ready for winter and this weekend's Storm we just had So i took her out, dusted her off put some gas in it and fired it up...had to pull start it because the battery was dead. She fired up after two or three pulls and was running fine I checked the Battery Charge light and it was glowing red... after maybe 5 minutes or so i noticed the charge light was off so i thought, wow that was fast... so I shut it down and tried to restart it with the electric start... nothing, battery was still dead...
so I pull started it up and the charge light came back on. So now i am watching the charge light and it begins to fade away until it went off, then I noticed smoke coming from under the generator motor, (the part that makes the electricity) so i shut it down.
I looked over the outside thinking maybe mice had made a nest in some vent or air intake or something but saw no evidence of mice... then i popped off the back cover and all the wires were hot, so I took out the 4 long bolts that hold the electric motor together and I slid out the inner part of the motor and there it was... a thick cord of wires going to the windings on one side were burnt to a crisp...and it also looked like there was rust or what looks like rust on the inner part that this thing spins on, I think it's called the Armature (not sure though) And remember, there was nothing plugged into this at the time, the only "Load" on it was its own battery that was being charged.
I bought this gennie brand new, used it for 9 days in 2011, not 9 days straight though, I only used it during the day, I shut it off at night when we went to sleep. after that I would just take it out and start it up every now and then to let it run for 10 mins or so. It always fired right up with no issues till now! Its a Duromax XP8500E thanks!

 

[wyliesdiesels]

Oouucch
Dont think thats repairable

 

[theoldwizard1]

Oouucch
Dont think thats repairable

Not cost effectively !


Quick engineering lesson. What we all call a generator is technically an alternator because it makes alternating current, AC (funny, because alternators in cars make direct current, DC. The current becomes DC after it goes through the rectifier diodes).

The thing that spins inside of an alternator is the field. (On an old fashioned true DC generator the field was stationary and mounted outside of the spinning armature.)

One of the benefits of an alternator is that it is easy to adjust the voltage by adjusting the magnetic force creating the field by increasing/decreasing the voltage going INTO the field.

The 12V output on a generator is really part of the "exciter" circuit, which is used to "kick start" the whole current generation process.



My SWAG is that the OP burned the exciter winding because the battery was flat dead or had an internal short. If the rest of the windings are good, it might be repairable. Then again, if you can't get the part, winding your own excitation coil is NOT something I would want to do !

 

[zacker01]

So it may just be in my best interest to buy another generator?

 

[MBfreak]

A rewinding shop will repair your generator. This will be a rewind to replace the burned part of the stator winding. It will also include a check of the battery charger circuit in the genset, which may be a cause for the overload/burned wiring. It can be as simple as a shorted out rectifier bridge. A check of all internal fuses/MCBs is also needed.
Also the rotor must be inspected. It seems that some copper particles have rubbed on the rotor lamination. This needs to be repaired to have a consistent air gap all over ( 0,5-0,8 mm I guess. Check rotor bearings too.

It may also be that the fault is only in the winding, where the enamel on the wires may have been damaged, somehow. Even one short circuited winding turn will lead to a burnt stator winding.

Go for repair!

Ola

 

[yeldogt]

We used to have a local motor shop / starter alternator shop / small appliance repair shop ... the local HRD store rewired lamps. Now all gone .. when one of my pool pumps died a few years back that last guy around asked me "how old" .... because if it was old enough to be a USA motor .. it may have been repairable .. otherwise forget it. Oh -- and you can buy a new one made in China cheaper vs what I can fix it for no mater what's wrong with it.

He is no longer around ...


I would call around -- maybe get lucky. Or find someone on e-bay with a bad motor

 

[Ole Slewfoot]

Look for a cheap chinese generator that doesn't run, and swap heads.

 

[Showkey]

Look for a cheap chinese generator that doesn't run, and swap heads.

Poor quality generator side witha quality power head does not help the situation ..........especially during long run times during the next storm.

We have hashed and rehashed generators many times ...........quality costs.

 

[Ole Slewfoot]

I'm sure the OP is painfully aware that purchasing a good generator is best for reliability.
But with a $free-100 parts donor, he might get years more out of this one.

 

[theoldwizard1]

A rewinding shop will repair your generator.

I live in a major metropolis (in the top 20 in the US). I don't think there is ANY "rewind shops" within 200 km that would deal with such a "small" generator.

50+ hp motors, probably.

 

[Chilliwack Murray]

Looks like your generator had a dedicated winding for charging the battery, sometimes called a quadrature winding... unfortunately these are usually only meant to maintain the battery and charging a dead battery will fry it. This is true of most portable and mobile units.

As so someone else mentioned, it is often also used to provide field current and if that is the case, your unit will not produce AC power. You miht get lucky and find it will still run but not charge the battery but odds are slim.

Your cheapest and best option (as someone else also said) would be to find an organ donor and swap the parts.

 

[bczygan]

Electric start?

Fancy!

 

[zacker01]

Looks like your generator had a dedicated winding for charging the battery, sometimes called a quadrature winding... unfortunately these are usually only meant to maintain the battery and charging a dead battery will fry it. This is true of most portable and mobile units.

As so someone else mentioned, it is often also used to provide field current and if that is the case, your unit will not produce AC power. You miht get lucky and find it will still run but not charge the battery but odds are slim.

Your cheapest and best option (as someone else also said) would be to find an organ donor and swap the parts.

Hmmmm Interesting... Every other time I started this thing it was with the electric start and it ran great... this time though the battery was stone cold dead... and yes, it would not make power either. She still runs great but it wont make power, charge the battery and the electric motor part smokes and will probably just fry up even more... lol

 

[zacker01]

I'm sure the OP is painfully aware that purchasing a good generator is best for reliability.
But with a $free-100 parts donor, he might get years more out of this one.

you are right... id rather not have to spend $1000.00+ on a new one. but if im going to spend $500.00 on a **** shoot.. maybe I should just bite the bullet and get something like a Generac or another more main stream brand? I mean, Duromax doesnt even have a list of authorized repair shops they can give you. If it were still under warranty, they tell you to go get it fixed and send them the bill for the parts. lol... They dont even tell you where you can get parts for it.

 

[zacker01]

We used to have a local motor shop / starter alternator shop / small appliance repair shop ... the local HRD store rewired lamps. Now all gone .. when one of my pool pumps died a few years back that last guy around asked me "how old" .... because if it was old enough to be a USA motor .. it may have been repairable .. otherwise forget it. Oh -- and you can buy a new one made in China cheaper vs what I can fix it for no mater what's wrong with it.

He is no longer around ...


I would call around -- maybe get lucky. Or find someone on e-bay with a bad motor

Maybe.... I will have to make some calls...

 

[zacker01]

A rewinding shop will repair your generator. This will be a rewind to replace the burned part of the stator winding. It will also include a check of the battery charger circuit in the genset, which may be a cause for the overload/burned wiring. It can be as simple as a shorted out rectifier bridge. A check of all internal fuses/MCBs is also needed.
Also the rotor must be inspected. It seems that some copper particles have rubbed on the rotor lamination. This needs to be repaired to have a consistent air gap all over ( 0,5-0,8 mm I guess. Check rotor bearings too.

It may also be that the fault is only in the winding, where the enamel on the wires may have been damaged, somehow. Even one short circuited winding turn will lead to a burnt stator winding.

Go for repair!

Ola

So on that Rotor... could it be that maybe the bearing was bad causing the stator to hit the rotor and wear away the jacketing on the wire making it short? those marks shouldn't be there on the rotor correct? Also... is the rotor supposed to be fully coated with that yellow/green coating?

 

[American Locomotive]

The little rust streaks are fine. The battery in the generator is probably shorted and cooked the 12v winding. For kicks you can try disconnecting the battery and see if it starts generating again.

 

[zacker01]

The little rust streaks are fine. The battery in the generator is probably shorted and cooked the 12v winding. For kicks you can try disconnecting the battery and see if it starts generating again.

Hmmm... but what about the fried wires? wont they still be frying and shorting or should i try covering them first with something like that liquid electrical tape stuff or some sort of glue?

 

[zacker01]

Also guys, About the rust streaks on the Rotor? should i try to remove it with some light grit sand paper? or even just try to rub off as much as i can with a dry rag?

 

[theoldwizard1]

those marks shouldn't be there on the rotor correct? Also... is the rotor supposed to be fully coated with that yellow/green coating?

Those look more like rust to me. If there was an interference, the marks would be shiny.

The coating is an epoxy/lacquer to prevent moisture from getting in.

 

[theoldwizard1]

The little rust streaks are fine. The battery in the generator is probably shorted and cooked the 12v winding. For kicks you can try disconnecting the battery and see if it starts generating again.

Hmmm... but what about the fried wires? wont they still be frying and shorting or should i try covering them first with something like that liquid electrical tape stuff or some sort of glue?

The fried wiring appears to be on the 12V winding. I would disconnect (cut) that. Depending on the rest of the wiring/circuitry, it may or many not just start to work !

Get a DMM, even a cheap one like the $5 HF and check the resistance across the slip rings. Shorted or open is bad. It should be a fairly low number.

 

[Ole Slewfoot]

you are right... id rather not have to spend $1000.00+ on a new one. but if im going to spend $500.00 on a **** shoot.. maybe I should just bite the bullet and get something like a Generac or another more main stream brand? I mean, Duromax doesnt even have a list of authorized repair shops they can give you. If it were still under warranty, they tell you to go get it fixed and send them the bill for the parts. lol... They dont even tell you where you can get parts for it.

Then they'd have to admit they are the same as 98% of the other Chicom generators of a certain age.

 

[zacker01]

The coating is an epoxy/lacquer to prevent moisture from getting in.

Is it important if its not covered 100%? I dont know if it melted off, wasn't coated that much to begin with or whats on the rotor is coating that melted off the winding's and ended up there...lol

At any rate... I was looking at Generators on the Consumer Reports site and its between the Kholer 7500 and the Troy built 7000 as far as price and ratings go. The Kholer is about $1500.00 the Troy built is $900.00 Needles to say, I am NOT looking forward to spending that much on a new Generator....

 

[apollo11]

how did the HF predators hold up ?

 

[theoldwizard1]

Is it important if its not covered 100%?

I should have said "it is an epoxy/lacquer coating is an INSULATOR that electrically insulates each wire from any neighboring wires and prevent moisture from entering".

It is EXTREMELY important that it is intact. That is why I said

Get a DMM, even a cheap one like the $5 HF and check the resistance across the slip rings. Shorted or open is bad. It should be a fairly low number.

The wires on the stator should also be checked for resistance, but that is more complicated.

 

[Platonic Solid]

At any rate... I was looking at Generators on the Consumer Reports site and its between the Kholer 7500 and the Troy built 7000 as far as price and ratings go. The Kholer is about $1500.00 the Troy built is $900.00 Needles to say, I am NOT looking forward to spending that much on a new Generator....

Considering that your current 8500W model was selling at HD for $718 (link), it's pretty obvious you get what you pay for. My 20Kw Generac was over $4,000 in 2007 and has cost me nothing outside of minor basic maintenance over the past 10 years. Ran just fine providing whole house power for 24 hrs. after the storm earlier this week.

 

[zacker01]

how did the HF predators hold up ?

Scores range from 41 to 91 The Honda #EU7000is was the highest scoring generator reviewed with a 79.
The “All Power” APG3560 came in lowest with 41 points!

The only Predator reviewed was the 68529.
It Came in #5 out of 23 different models reviewed.
Scorecard...
Power delivery
Good

Power quality
Very Good

Noise
Fair

Ease of use

Very Good

Run time range (hrs.)
7-12 hrs.

Highs:
Provided clean power with consistent voltage. Easy to start and has some helpful features. Has fuel shutoff. Includes low-oil shutoff, which protects the engine from overheating if the oil level dips too low. Also displays a low oil light to tell you why it shut down.

Lows:
Delivered enough wattage to power our test appliances but could not handle surges well. Fairly noisy from a distance of 23 feet; we recommend hearing protection for standing close. Requires separate purchase of wheels, $25. Lacks an hour meter, which tells you how long you've run the generator since your last oil change.

CRs Take:
Has fuel shutoff, which lets you draw gas from the fuel system to keep it from fouling parts if it degrades during storage. It also prevents leaks. Includes low-oil shutoff, which protects the engine from overheating if the oil level dips too low. Also displays a low oil light to tell you why it shut down. Wheels are optional. Has a 6.6 -gallon tank. Has a fuel gauge. Has 5 power outlets.
Detailed Test Results

POWER DELIVERY: Delivered enough wattage to power our test appliances but could not handle surges well. POWER QUALITY: Provided clean power with consistent voltage. NOISE: Fairly noisy from a distance of 23 feet; we recommend hearing protection for standing close. EASE OF USE: Easy to start and (for portables) transport, with some helpful features for starting and operating the generator.

About:
The Predator 68529 is part of the Generator test program at Consumer Reports. In our lab tests, Generator models like the 68529 are rated on multiple criteria, such as those listed below.
Power delivery: How much wattage models delivered and how well they handled surges in power demand over various loads.
Power quality: A generator's ability to deliver power smoothly, with consistent voltage.

Noise: Measured at 23 and 50 feet from the generator. We recommend hearing protection for standing close by the unit while it's running.

Features & Specs
Specs:
Claimed output (watts)
5500

Fuel type
gasoline

Weight (lbs.)
206

Fuel shutoff
Yes

Low-oil shutoff
Yes

Electric start
No

Fuel gauge
Yes

Hour meter
No

Low-oil shutoff has indicator light
Yes

Electric-start battery included
N/A

Wheels
optional

Fuel capacity
7

No. of power outlets
5

 

[Ole Slewfoot]

i could say the same about my Champion, except after rebate Orilley paid me $50 to own it, and I did buy new oil for it a couple times.

 

[zacker01]

Considering that your current 8500W model was selling at HD for $718 (link), it's pretty obvious you get what you pay for. My 20Kw Generac was over $4,000 in 2007 and has cost me nothing outside of minor basic maintenance over the past 10 years. Ran just fine providing whole house power for 24 hrs. after the storm earlier this week.

Exactly what I was thinking... If I only knew then what i know now Id'a bought a good one and spent a little more for it.

 

[apollo11]

I was hoping they reviewed the #63584 3500 watt inverter generator.
Thanks

Scores range from 41 to 91 The Honda #EU7000is was the highest scoring generator reviewed with a 79.
The “All Power” APG3560 came in lowest with 41 points!

The only Predator reviewed was the 68529.
It Came in #5 out of 23 different models reviewed.
Scorecard...
Power delivery
Good

Power quality
Very Good

Noise
Fair

Ease of use

Very Good

Run time range (hrs.)
7-12 hrs.

Highs:
Provided clean power with consistent voltage. Easy to start and has some helpful features. Has fuel shutoff. Includes low-oil shutoff, which protects the engine from overheating if the oil level dips too low. Also displays a low oil light to tell you why it shut down.

Lows:
Delivered enough wattage to power our test appliances but could not handle surges well. Fairly noisy from a distance of 23 feet; we recommend hearing protection for standing close. Requires separate purchase of wheels, $25. Lacks an hour meter, which tells you how long you've run the generator since your last oil change.

CRs Take:
Has fuel shutoff, which lets you draw gas from the fuel system to keep it from fouling parts if it degrades during storage. It also prevents leaks. Includes low-oil shutoff, which protects the engine from overheating if the oil level dips too low. Also displays a low oil light to tell you why it shut down. Wheels are optional. Has a 6.6 -gallon tank. Has a fuel gauge. Has 5 power outlets.
Detailed Test Results

POWER DELIVERY: Delivered enough wattage to power our test appliances but could not handle surges well. POWER QUALITY: Provided clean power with consistent voltage. NOISE: Fairly noisy from a distance of 23 feet; we recommend hearing protection for standing close. EASE OF USE: Easy to start and (for portables) transport, with some helpful features for starting and operating the generator.

About:
The Predator 68529 is part of the Generator test program at Consumer Reports. In our lab tests, Generator models like the 68529 are rated on multiple criteria, such as those listed below.
Power delivery: How much wattage models delivered and how well they handled surges in power demand over various loads.
Power quality: A generator's ability to deliver power smoothly, with consistent voltage.

Noise: Measured at 23 and 50 feet from the generator. We recommend hearing protection for standing close by the unit while it's running.

Features & Specs
Specs:
Claimed output (watts)
5500

Fuel type
gasoline

Weight (lbs.)
206

Fuel shutoff
Yes

Low-oil shutoff
Yes

Electric start
No

Fuel gauge
Yes

Hour meter
No

Low-oil shutoff has indicator light
Yes

Electric-start battery included
N/A

Wheels
optional

Fuel capacity
7

No. of power outlets
5

 

[theoldwizard1]

I have about a 20 year old Craftsman 5500 watt generator. It was either made by Generac or Briggs and Stratton (back in that time frame they cross licensed/built generators). It has a pull start 10 HP Briggs and Stratton engine.

First, this generator has never been "worked hard". I got it cheap from a neighbor. But the thing starts easily on the first or second pull, even in the middle of winter.

Second, I try to drag it out and fire it up every couple of months. Sometimes those "couple of moths" turn into 4 or more, so it does not get a lot of TLC.

This year, I was a "good boy". I pulled it out of the garage and drained all of the fuel out of the tank. Boy was it dark ! Then I sprayed some carburetor cleaner in the tank with the unit tilted so it would run down the the fuel petcock. For good measure, I followed that with some brake cleaner.

Fresh, stabilized gas and it started on the first pull ! For a load, I plugged in my 2HP 240V air compressor which I used to blow out my pressure washer. After the pressure washer was done, I ran the compressor for awhile with the drain open. 3 outdoor power tools put to bed for the winter !

As I re-arranged the outdoor equipment in the garage, I pulled out the snow blower. Last year I added a fuel shutoff valve and ran the carburetor dry. Turned on the gas, primed the carburetor, pulled the choke and it fired on the 3rd or 4th pull. I sure hope I don't need it for at least another month.