To make a long story short, I had to make a repair to the engine portion of my portable generator and decided it would be a good idea to run the generator to test my repair.  The engine runs fine now, but the voltage seems a bit high to me.  With no load on the generator the voltage is about 132 V on both sides (the generator is capable of producing 120 or 240 V).  With a 26W CFL plugged into each side, the voltage drops slightly to 130 V.  After warming up for half an hour (it's about 20* right now) the output had dropped to 128 V.  This still seems a bit high to me, but I wanted to know what the experts think.

I should point out 2 things: the engine never did reach full operating temperature and was running with the choke lever 1 notch away from full choke.  Forcing the engine to run with the choke lever in the "Run" position drops the voltage to 125V, but it ran rough and the voltage varied between about 123 and 127.  Also, this generator is rated at 5600 W, so a couple of CFLs would have a very small effect on the output.  Would a larger load or a warm engine bring the voltage closer to normal?  This generator is a backup for the house, so I'm mainly concerned with damaging delicate electronics like the computer.

The higer the rpm's the higher the out put. If it runs ruff with the choke open and the engine is warm there be another issue, loose carb mount bolts, out of adjustment or even a fouled plug. Last month we lost power and it was in the mid 20's mine ran normal with the below average temps. What repair did you make? what Make, model is it


I meant with it choked and warm. It could be as simple as lowering the Idle with a meter hooked up and the engine warm

The output from portable generator will vary.

Portable generators provide unregulated power (voltage and frequency). They'll power electrical equipment well enough (fridge, washer/dryer, power tools, etc.).

But when electronic equipment is connected to them...that equipment may not work so well.  You need to attach regulators and filters to clean up that voltage to run the electronic things (TV, radio, computer, etc.).

Don't expect a stand-alone portable generator to replace the power feed to your home unless the output is regulated...and again, many portable generators have no output voltage/current/frequency regulation/control.

Posted By dollar on 02-22-2011 01:51 PM
The higer the rpm's the higher the out put. If it runs ruff with the choke open and the engine is warm there be another issue, loose carb mount bolts, out of adjustment or even a fouled plug. Last month we lost power and it was in the mid 20's mine ran normal with the below average temps. What repair did you make? what Make, model is it


I meant with it choked and warm. It could be as simple as lowering the Idle with a meter hooked up and the engine warm

Before we get sidetracked with the details, let me point out a few things.  The engine never did warm up.  I could put my hand right on it and it barely even felt warm.  Also, I'm only asking if this is problem or not.  I'm not currently asking how to fix it.  I know the basics of how generators work, but I don't have much first hand experience with the way they typically behave.  This generator is still relatively new and has only been used once before (during the summer).

This is a Craftsman 5600 Watt generator Model 580.325610
Since you want the long story of my repair, here it is.  We lost power recently, so I hauled out the generator for its second run.  Try as I might, I just couldn't get it to start.  Fortunately, the power came back on only half an hour later.  During the troubleshooting that ensued, I discovered that the engine would start using starting spray, but would then cut out again.  The fuel was getting to the carb. but no further.  It took a lot of work, but I finally got the carb. apart and discovered that the main port was plugged with an orange/brown film.  I recognized it immediately as the remains of the Fresh Start fuel preservative (how's that for irony?).  I cleaned out the blockage and reassembled it as carefully as I could.  All the bolts and nuts are tight.  There are no leaks and the engine starts easily.  The choke lever has 5 positions.  It runs in full choke for only a few seconds before it needs to be opened up a notch.  During this test, it never warmed up past this point.

Posted By craig on 02-22-2011 02:40 PM
The output from portable generator will vary.

Portable generators provide unregulated power (voltage and frequency). They'll power electrical equipment well enough (fridge, washer/dryer, power tools, etc.).

But when electronic equipment is connected to them...that equipment may not work so well.  You need to attach regulators and filters to clean up that voltage to run the electronic things (TV, radio, computer, etc.).

Don't expect a stand-alone portable generator to replace the power feed to your home unless the output is regulated...and again, many portable generators have no output voltage/current/frequency regulation/control.

Thanks craig, that's what I wanted to know.  Any recommendation on regulators?
(Sorry about the double post, you replied while I was answering dollar.)

Posted By ssmigin on 02-22-2011 02:53 PM

Posted By craig on 02-22-2011 02:40 PM
The output from portable generator will vary.

Portable generators provide unregulated power (voltage and frequency). They'll power electrical equipment well enough (fridge, washer/dryer, power tools, etc.).

But when electronic equipment is connected to them...that equipment may not work so well.  You need to attach regulators and filters to clean up that voltage to run the electronic things (TV, radio, computer, etc.).

Don't expect a stand-alone portable generator to replace the power feed to your home unless the output is regulated...and again, many portable generators have no output voltage/current/frequency regulation/control.

Thanks craig, that's what I wanted to know.  Any recommendation on regulators?
(Sorry about the double post, you replied while I was answering dollar.)

It'd be best to purchase the recommended regulator for your Craftsman/Sears model.

Myself, I have a Coleman PM0435001 that provides 5KW but can generate upwards of 6250 watts -but not prolonged.
When/if I hook it up to my house for power, it's solely for the fridge and lighting.  Nothing electronic.

I got my generator in July 2006 mainly for job site use (power tools) yet have used it to sustain household appliances during long term power outages...and when that happens, I'm also powering my neighbor.

Basicilly, we coomunicate and rearrange plugs as needed so my generator doesn't get damaged.

To date, it's been used about two dozen times to power my home and my neighbor's for necessities.  The longest stretch was roughly 48 hours.

Hmm, that could be a problem. The generator itself doesn't appear to have a regulator except for the mechanical governor. The manual doesn't recommend one either. How do I get started on this?

I'd hate to give up now considering all the work that went into installing the receptacle and transfer switch.

Posted By ssmigin on 02-22-2011 04:34 PM
Hmm, that could be a problem. The generator itself doesn't appear to have a regulator except for the mechanical governor. The manual doesn't recommend one either. How do I get started on this?

I'd hate to give up now considering all the work that went into installing the receptacle and transfer switch.

Sears should be able to help you out with this.

I've seen regulators for my Coleman that started at $55...

Mind if I jump in here for a couple of questions??

I'm interrested in the 'regulator' you talk aobut Craig. I, too, have (2) generators. I've needed to power my house several times during the 7 years I've lived out in the boonies.
Like Steven, my voltage varies quite a bit. I have two Generac generators, a 4000, and a 3500. I THINK, they have built in regulartors in them. ? There are a lot of electronics behind the panel that has the 120v-30 amp, the 220v, 20amp and the two 120v, 15 amp recepticals mounted on it. I know, 'cause I took both of them apart to install an hour meter on them (12v,meter, wired directly to the BACK side of the 12VDC plug for charging batteries.)
As Steven pointed out, the engine was cold and was running on 1/2 choke. That may have been an indicator that the blockage was there, or getting started, so that the engine wasn't running up to full power. ?
My questions center around the same aspect, that being that engine RPM seems to control the Voltage output. One of my generators , when under about a 1/2 load was only putting out about 108vAC. Everything that I had connected seems to be operating properly, so I'm wondering if there is a problem. Could my engine be running to slow?
I did run some carb cleaner through it, and have stablizied gas in it. I use SeaFoam to "keep" it clean, but don't run it as often as I should.
I use it (either of them) to power my entire house. I've taken current readings and with furnace, a few lights, refer, well pump, and well pump heater, I'm still at only about 9amps draw. So, other than voltage being a little on the low side, I think it's O.K.
Will the voltage come up if I would run the generator more? I tried operating the governor manually, and the voltage did come up, so is my (problem) just low engine RPM?
Maybe my Sta-Bil is failing me too?
Thanks

Bob--I am not meaning to answer for Craig or steal his thunder in ant way but was a Generator in USMC a long time back and if it were me I would advise cranking the rpm up til you get the desired voltage. Too low of a voltage con harm your equipment that is running on it.


Wolf

Thanks wolf,
I'll have to investigate that....The generator does change RPM with load, so I probably didn't make that real clear. I always figured it was 'automatic' but will investigate for a high speed adjustment. The unit does vibrate quite a bit while running, so that may be all I need to do....Thanks
(never thought of that! duh)

BOB:
Several years back (15/20 or so) I took a Generator Repair Class at work. If I remember correctly (and YES that is getting tougher) we used a Tachometer to adjust the motor until it ran at 5500 rpms I believe. It was a small portable Tack that set on top of the running eng. and the vibrations controlled the reading on the Tach I'm almost sure we set it at 5500 rpms but that could be checked out in a Owners Manual spec.'s section.

Steven:
Portable Generator's produce what my instructor called "Dirty Electricity as it was unregulated" Do not run todays hi-tech equipment on it per his instructions also.
Sounds like your carb. got vanished up and I would suggest you buy a small carb. cleaner bath can. You place the parts in the can with the cleaner and let it soak a good day or two. Blow out the carb and clean the jets with a air compressor.
One other thing I found on a hard to start small engine of my Log splitter was a cracked primer bulb sucking air. Do you have a primer bulb? With all this Ethanol being added to our gas they eat up rubber parts like a primer bulb quite easily.

Posted By Bob from Necedah on 02-23-2011 09:09 AM
Mind if I jump in here for a couple of questions??

I'm interrested in the 'regulator' you talk aobut Craig. I, too, have (2) generators. I've needed to power my house several times during the 7 years I've lived out in the boonies.
Like Steven, my voltage varies quite a bit. I have two Generac generators, a 4000, and a 3500. I THINK, they have built in regulartors in them. ? There are a lot of electronics behind the panel that has the 120v-30 amp, the 220v, 20amp and the two 120v, 15 amp recepticals mounted on it. I know, 'cause I took both of them apart to install an hour meter on them (12v,meter, wired directly to the BACK side of the 12VDC plug for charging batteries.)
As Steven pointed out, the engine was cold and was running on 1/2 choke. That may have been an indicator that the blockage was there, or getting started, so that the engine wasn't running up to full power. ?
My questions center around the same aspect, that being that engine RPM seems to control the Voltage output. One of my generators , when under about a 1/2 load was only putting out about 108vAC. Everything that I had connected seems to be operating properly, so I'm wondering if there is a problem. Could my engine be running to slow?
I did run some carb cleaner through it, and have stablizied gas in it. I use SeaFoam to "keep" it clean, but don't run it as often as I should.
I use it (either of them) to power my entire house. I've taken current readings and with furnace, a few lights, refer, well pump, and well pump heater, I'm still at only about 9amps draw. So, other than voltage being a little on the low side, I think it's O.K.
Will the voltage come up if I would run the generator more? I tried operating the governor manually, and the voltage did come up, so is my (problem) just low engine RPM?
Maybe my Sta-Bil is failing me too?
Thanks

I've looked at the innards of mine.
Most of what I got are diodes, capacitors, something that I 'assume' are inductors...which leads me to believe they're there to filter as best as possible the output to roughly 115VAC at 60 Hz.

If you and I want regulated 115 VAC at 60 Hz...the typical portable generator isn't going to do it.

Got it, thanks, Craig

Probably the same for mine...
I did get down on my knees and take a good look. The governor spring has a bracket with a long threaded area and a nut on it. I started the unit and adjusted (tightened, or made shorter) that threaded area, and the RPM's picked up quite a bit. If I get some sun out tomorrow, I'll load the unit down and adjust or check the adjustment to maintain the 115V. I'm thinking that the nut just vibrated out over the years.
Thanks to all.

Oldman, my generator does not have a primer bulb.  Also, the manual specifically says that a 10% ethanol mixture will not harm the generator and I have not noticed any degradation of any of the parts.  I cleared the blockage and cleaned the parts with a carb. cleaner spray.  A small amount of residue remains, but it is more like a stain than a blockage.  Ice and snow are predicted tomorrow, so I won't be working on the generator again until we're in the clear (might need to take whatever it can give).

I plan to retest the generator in warm weather.  If these problems still exist, I will be replacing the plastic insert that got clogged.  No point in wasting any more time on a cheap part.  I added a bottle of STP complete fuel system cleaner to the tank to help out in the mean time.

The only other time this generator was used, it put out something like 123V while connected to the house.  The computer, TV, and everything else ran just fine.  The only exception was the clock-radio that relied on the 60 Hz from the wall to regulate the time.  Since the generator was putting out 62 Hz, the clock ran fast.  This is the first time I've ever checked the voltage during a no-load condition.

Thanks to everyone for the input.