Generator high voltage?

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  #1  
Old 04-15-14, 11:32 AM
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Generator high voltage?

My portable generator is giving me about 129VAC. That's very high isn't it? Does this indicate a problem? I assume it will be for whatever I plug into it.

I should also note this is under load (I used a 1500 watt heat gun). With nothing plugged in its at 130vac.

Would this type of voltage damage a sump pump? Or other stuff for that matter?
 

Last edited by zmike; 04-15-14 at 12:17 PM.
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  #2  
Old 04-15-14, 01:09 PM
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I should mention, this generator is about 8 years old and has never been used besides periodic starting and oil changes.

Is the voltage adjustable?

Its a briggs and Stratton 030424

I don't think this generator has a voltage regulator, so I assume I have to set the idle somehow which I have never done before. Maybe I posted this in the wrong section... is there a generator section that would help me get this working properly?

Question remains about the damage 130 volts will do?
 

Last edited by zmike; 04-15-14 at 01:42 PM.
  #3  
Old 04-15-14, 02:43 PM
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It's not as bad as you think.

The standard delivery voltage is considered to be 120 +/- 5% so you could see up to about 126 volts. Odds are your meter is not calibrated either.

Before you do anything get yourself a tachometer or a frequency meter. Ideally the engine would be running at 3600 rpm, or 60 hertz. Normally a conventional generator is set up for about 63hz, no load, to account for "droop" when under load.
 
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Old 04-15-14, 03:16 PM
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I don't have a frequency meter but the 130 volts was measured on 2 multimeters... a low impendence Fluke and a cheap-o Sears Robuck... both indicated about 128 under load and 130 no load. Calibration is not the issue and what I am seeing is over that five percent.

What is that going to do to my sump pump and fridge?

Since there is no voltage regulator, I think I have to figure out how to dial down the idle also this thing has sat unused for the most part over the past 8 years, perhaps I need to clean/lubricate something ??
 
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Old 04-15-14, 03:28 PM
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Do NOT set the generator by voltage. The frequency also needs to be correct.

As I said you need a tachometer or a frequency meter to set the RPM's.

Very few devices will have problems. Most computers, a/c adapters, basically almost anything with a switching power supply can run over a wide range of voltages.

It's not high enough to damage motors.

You really have nothing to worry about.
 
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Old 04-15-14, 03:41 PM
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Yes as stated set the Hz... That is more important...

Get yourself a killowatt meter...

You adjust the idle by the governor.. I small tang gets bent to adjust...

Killowatt meter...

Amazon.com: P3 International P4400 Kill A Watt Electricity Usage Monitor: Home Improvement

The paperclip looking wire that goes to the tang. That tang gets bent forward or back to adjust the rpms. Set to about 62hz... When a load is put on the gen it should bring it to around 60hz...


 
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Old 04-15-14, 04:46 PM
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So your saying I have nothing to worry about with 130vac?

If the poco was giving me 130 I would be having a fit. Im sure my stuff would be giving up the ghost sort to speak.

So the spring is pulled forward or apart to set RPM... the 130 suggests I am on the high side of 60hz? Is there a more detailed description online on what I should do? Wished I had the service manual!
 
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Old 04-15-14, 04:57 PM
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Google the brand of generator for a manual. I did that on my Honda jobsite 1000 watt. I set the RPM too high and it blew out light bulbs. Learned via the manual to set the frequency. It has a built in frequency meter, which keeps it around 12 to 128 volts. Nothing is stable, of course, but it sure beats not having power when you need it.
 
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Old 04-15-14, 04:59 PM
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So the spring is pulled forward or apart to set RPM
No. The metal tang that paperclip looking wire attaches to gets bent to adjust..

the 130 suggests I am on the high side of 60hz?

Could be. You need to check the Hz.. Some higher end meter have this capibility. Check your fluke meter for this option.

Is there a more detailed description online on what I should do? Wished I had the service manual!
Its a briggs and Stratton 030424
Should be able to get the manual here. need the # off motor.. Series # I believe...

Customer Support
 
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Old 04-15-14, 07:25 PM
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Just as a note, normal voltage range is +/- 10% not 5%. So 120 volts +/- 10% is up to 132 volts. Yes, your generator is on the high side, but it is within tolerance. You have also seen how the voltage will drop when you put a load on it.
 
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Old 04-15-14, 08:46 PM
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ANSI C84.1 is the standard for electric power systems and equipment. It specifies 5% nominal tolerance so the range would be 114-126 for a service.

NEMA recommends a 10% tolerance for electric motors.
 
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Old 04-23-14, 12:38 PM
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I did find a service manual an how to adjust the idle but I am hesitant to do so as I don't want to get it out of whack sort to speak....

even if it falls within that 10 percent, should I seriously consider dialing it down?

I assume sensitive stuff like TV and computer wont like 130... am I correct?

(not saying I need the TV when the power goes out, my main concern is sump, fridge, space heater and some light)
 
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Old 04-23-14, 02:25 PM
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Does your generator actually idle? It has an automatic throttle? Many conventional generators, non-inverter, don't. They run at approximately 3600 rpm no matter what the load.

Don't try to adjust the RPM without the proper tools. Frequency is determined by RPM and is just, if not more so, important than the voltage being just a little high.

Check your TV and other devices. Many computer supplies can easily tolerate a wide range, like 100-240 volts. Switching power supplies are very tolerant.
 
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Old 04-23-14, 03:02 PM
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Plug in your space heater and turn it on to "high". Then take a voltage reading. I suspect it will drop considerably.
 
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Old 04-23-14, 03:46 PM
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Like #1 here, your fluke meter should be able to test Hz...

 
  #16  
Old 04-23-14, 04:26 PM
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Plug in your space heater and turn it on to "high". Then take a voltage reading. I suspect it will drop considerably.
I was using a 10A heat gun and it was only going down from 130 to 128... perhaps if I loaded up the other leg as well it would drop further.

Unfortuently my multimeter doesn't test HZ.

How does age or lack of use play into this? For about 5 years this generator sat unused without gas in it and the original oil. When I went to fire it up for the first time I changed the oil, filled it up with gas and it started right up.
 
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Old 04-23-14, 11:11 PM
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Purchase a Kill-A-Watt unit. About $30 at th home stores, and a very handy unit. Measures volts, watts, amps, volt-amps, power factor, hz, KWH, among other things I may be missing.
 
  #18  
Old 04-24-14, 12:16 PM
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How does age or lack of use play into this? For about 5 years this generator sat unused without gas in it and the original oil. When I went to fire it up for the first time I changed the oil, filled it up with gas and it started right up.
If a spring on the governor is out of tolerance, or a capacitor (if you don't have an AVR) then the voltage can be off but so can the RPM.

I know I sound like I'm nagging you about this but really, you need tools to do the job correctly. The Kil-O-Watt meter will help. RPM and frequency are what you set, not the voltage.
 
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