I have a Generac 5500 Watt generator model 09778-3 that has approx 5 hours of total use on it. I went to use it a couple of weeks ago to power a 1-1/2 HP pump that draws approx 9 amps at 240 volts. I had used this generator for this purpose before with good results. This time the generator ran under load for approx 30 seconds and all of a sudden speeded up a bit. Further checks showed that there was no output of any kind. Even the solenoid voltage for the idle slowdown under no load conditions, wasn't there. Absolute zero on any plug. Each pushbutton circuit reset button was pushed and no results.
I checked with all the "Authorized" Service centers here locally and all but one didn't work on the generator portions. I took to the one service center and they took the generator to work on. First of all, they were very cautious about taking it at all, because "they usually didn't work on generators."
Their prognosis was that the stator was shorted. I hadn't noticed any smoke, smell or anything when it had quit generating. The mechanic admitted that he had taken his readings with an analog meter, and my being an electrician by trade, I know that motor/generator readings are so low that an analog meter won't give you accurate readings. I can take readings with a fluke digital meter and I do have a wiring diagram, but I have no idea what these readings should be. Can any one be of any help. This generator looks brand new and has an 11 HP B&S motor that runs like a top. I have talked to Generac and because the whole unit is 4 years old, it is out of warranty, even though it only has the 5 hours on it. Mechanic quoted $785.00 plus shipping plus labor to install stator. Pretty steep for a generator that you can buy new for less than $600.00. Brushes, comutator etc look like new.
I would really like to check it out a little further myself. Does anyone have suggestions or know where I can get resistance readings for stator. I sure would appreciate it.

Hello Bowler

Actually you have already found the cause of the problem.
You stated : "Even the solenoid voltage for the idle slowdown under no load conditions, wasn't there." I would spend my time on checking WHY there is no such voltage, as that voltage is normally used to induce the start magnetic field on which the generator can generate the full magnetic field and the output electric power.
Look at the magnets that generate that solenoid voltage. Are they still sufficiently magnetized? If not replace them (Radio Shack). Or disconnect the output of that selenoid and see if there is a short on that line elsewhere in the generator.

Success !

:)

I will be out there checking today. But I am not quite sure what magnets I am looking for. Are we talking about the magnets inside of the generator or is there something I am missing here? Surely the magnets inside the generator can't be replaced at Radio Shack.

I'd be looking for some kind or short circuit, or open circuit, in the load sensor. Try disconnecting completely to see if you can get any output to the receptacles.

I have schematic for this generator and the idle control solenoid voltage comes right out of the system control board. The DPE windings come out of a power regulation board. Boards are expensive. Is there any way to check these out? If anyone is interested, schematic of this generator is in a pdf format at
http://www.generac-portables.com/document/index.cfm?doc=9778_7EN2W_LO.pdf

This is almost like infant mortaility. I'd check any connections you can find for corrosion and/or looseness. Then I'd disconnect al the generator points and measure the resistance and the resistance to the case. I expect all readings to be low except the ones to the case. You won't be able to measure 1 ohm or less, so don't worry about it.

Write down the readings and we'll go from there. There isn't much troubleshooting info there when there is no equlivelent circuit diagram on the control boards.

I'd also be interested in the voltage between 11 and 44 with and without the power regultor board disconnected.

At this point, I suspect the power reg board myself. I will get back to you. Already took all thee resistance readings but didn't write them down. All looked normal to me with total infinity to ground. Will recheck in the morning and get back to you. Thanks for your interest.

Double check your model number and cinfirm back to us. Generac has a breaker protecting the out put but you've checked that by now, right?

Model 09778-3 There are 4 pushbutton circuit reset buttons. One for each circuit. I have not found one for a main circuit breaker. Yes I have checked the 4 I found. Even if one was tripped, the others would work the way it's wired.

Are you checking for continuity across the circuit breakers or just resetting? From the wiring diagram it appears that if a 30 amp is tripped it affects one of the 20 amps.

By the way, if you are looking for the model # somewhere else, use 09778 Don't use the -3 as this is apparently a sub model # or something. All schematics etc come up just using the 09778.

Well gentlemen... I am giving up on this generator and will post on Craig's list as is... but I did get the readings as requested. All readings were taken with a Fluke digital meter. The generator output across #11 and #44 was identical with or without the power regulator board connected or disconnected. Started at about 7 volts AC and dwindled down to about 1.75 volts.

Main power windings read .36 and .38 ohms All readings were taken with leads disconnected and coming directly out from generator. Specs supposed to be from .26-.36 ohms.

DPE exciter leads lifted and they read 2.14 ohms. Specs 2.26-2.8 ohms

Across wire terminals 1 and 4, ( field leads) .56 ohms

There is one big discrepancy and that the Clymers book that I just purchased, says that there should be infinity between DPE and power leads. I only have about 2.5 ohms between these leads. Infinity to ground. I question this infinity reading between leads, as I look at the Generac circuit on this generator and see Wire #2 and Wire #22 are connected and that would be 0 ohms between the leads. I have tried flashing the fields, both with a drill motor and with a 12 volt battery. Didn't do anything.

I thank all of you for your input and if you do have some more input, I'll gladly look it over.

I would not give up just yet unless a genrac authorized repair/dealer says its not worth fixing. We sent thousands of this model top Iraq as did Nato. Somebody must know how to fix it.

You looked at the wrong voltages:

Look at DPE (2,6) with and without the power regulator board connected.

Also look at the field (+,-) as a DC voltage when the regulator board is connected.

What probably happens is this:

DPE creates an AC voltage using the residual madnetism in the generator. It's rectified to a DC voltage and turned on and off by the shield gate signal and this excites the field. This is similar to a car alternator EXCEPT that there is no residual magnetism. The snubber feedback is probably a current limit. The residual magnetism is probably coming from the field, hence flashing the field.

So, I am expecting an AC voltage at DPE when the power regulator board is connected and disconnected. If that's not there, then you have a generator problem.

The shield gate signal is probably relative to pin 22.

Bet you don't hava an AC voltage at DPE with power regulator board disconnected and you don't have a DC voltage across the field terminals.

Then you need to look at the shield gate signal. The question is What's it relative to? Pin 22?

The rest of the circuit depends on a few things. The idle coil could be a voice coil positioner or a stepper or a motor. No idea.

Low oil pressure lights a LED and kills the engine.

The idle switch determines if it runs at the proper frequency all the time. i.e. If the idle speed reduces under no load. Have no idea of the sense of the switch from the schematic.

The idle control transformer is really a current transformer. Note that it's in SERIES with the output. A voltage between 155 and 156 determines whether current is flowing. If it is then the idle control coil maintains 60 Hz.

Looks like some voltage feedback might be between pins 22 and 11. That could be used for overvoltage protection. Just a guess.

It looks as though the output is isolated UNLESS the customer ground lug is used.

PS: I didn't read the manual. Just the schematic pages 14 and 15.

I suggest reading this article:

http://www.endtimesreport.com/dead_gen.html

I finally gave up on this generator. I found someone that was willing to buy the unit and wanted to take the generator off and install a portable water pump. Worked for him and it worked for me. Thanks all for the help and interest.

I have a 750w 1994 Motomaster portable generator. It has no power output

First off you need an analog meter with Rx1 setting and a .5 on the 0 side before getting to one, or a digital meter withy rx1 or rx10, most digital meterhave a variance arounf.7 so you won't read anything other wise.
The RV generators have more wires however the ohms readings are below 1 on a Rx1 scale. The good reading on a big rv for instance is 0.327 acroos the stator when the wires are tested. That bis even for 4 wire highes watt the first pair will read that and so will the second pair. The regulator plug with thinner wire will read around 2.089 ohms on the Rx1. These readings are from a 4kw rv genset with circuit boards
Hope this helps

http://www.endtimesreport.com/dead_gen.html... helpful info for recharging generator field... have used both methods listed with success

http://www.endtimesreport.com/dead_gen.html... helpful info for recharging generator field....have used both methods listed with sucess

Or To flash the field on a small home use generator,get an ext. cord & cut off the female end of it & strip the wires & connect the wires to a 12 volt car or lawn tractor battery, & plug the male end of the cord, into the 120 A.C. side of the generator.

Make SURE that the black wire which is POS/HOT on an A.C. cord, gets connected to the RED/POS. side of the auto battery, & the white wire on A.C. cord gets connected to the BLK./NEG. side of the battery. If the ext. cord wires are not black & white, then the smaller prong of the plug is the POS./HOT

Plug the other end of the ext. cord into the generators 120 volt side & remove spark plug wire, & pull the starter cord 4-5 times, then remove the ext. cord, reconnect the spark plug wire, start the unit & plug something of 120 A.C. volts in to see if it works. If it does then let it run for about a half hour with 2 -300 watt lights or something similar to help re-generate the unit.

Read more: Recharging generator field - DoItYourself.com Community Forums (http://www.doityourself.com/forum/outdoor-gasoline-powered-equipment-small-engines/188605-recharging-generator-field.html#ixzz2HhKfetCO)

I didn't look very hard to find a serviv=ce manual, but sometimes they are out there. You may nned the serial number to even look as in generac's site.

Here is "A service manual", but not for yours.

http://www.jackssmallengines.com/Generac-Parts-Lookup/Service-Manuals/0H5039revA%20-%20IX%20Invertor%20Diag%20Manual.pdf

I did find the resistance info your looking for: Generac 5500XL, model#09778-7 no output. Changed - FixYa (http://www.fixya.com/support/t3950789-generac_5500xl_model_09778_7_no_output)

Remember that there are probably two output windings and a control. There needs to be enough "residual magnatism" to get the generator kick started.

In MANY cases, you will get no output if protection sensors aren't working.

If you don't have a 4 or 5 wire ohmmeter, or an ohmmeter that can be zeroed or a constant current source, you'll have to resort to another technique using an ammeter or known resistor and a voltmeter.

An example, you should be able to get a 10 ohm precision resistor of sufficient wattage and a D battery. I = 12/(10+0.3) is a little over an amp. P = I*I*R or 1*1*10 or about 10 Watts.

you can add 3 Amp fuse to. So, what you need to do is put a voltage source, fuse, known resistor that won't damage anything.

I'd recommend making your own 4-terminal resistor. Take a small size wire and a large AWG wire and solder to each end. The large wires will be current and the small wires voltage. Initially use the Ammeter function of your meter (again pay attention to the internal resistance to the point that it will current limit stuff). The current is the same everywhere and the Voltage is defined to be those two small wires (Say 22 AWG). By using R - V/I, you now have the value of your precision shunt. You will need two DVM's this way.

Now use the shunt, fuse, battery. And power supply and do the same thing. Measure the voltage across the resistor and the voltage across the coils. Do the math to determine current and finally resistance of the windings.

Instead of the fuse, you could substitute 1 or 2 12 V high intensity lamps in parallel for the fuse. The light bulb is a current dependent resistor. So if you use 12 v supply and a 1.5 Amp bub, the current will be limited to 1.5 Amps.

So, you really have to measure the VOLTAGE ACROSS the DUT (Device Under test) and the CURRENT through the DUT using currents and voltages that don't damage. Paying attention to protections like a light bulb and current limiting caused by the shunt in your ammeter.

if you have an ammeter, a voltmeter and a variable power supply either current limited or with a fuse in series, life is easier.

Measuring 2 ohms with your run of the mill DVM is nonsense. Using a 4 or 5 terminal DVM, now we are talking.

Non-use may actually mean that the generator needs reflashing to put the residual magnetic field back. Polarity needs to be right.

I hope this makes sense.