Backup Generator

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Cody K

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Location
Texas
Today we had a temp power outage due to lighting in area. I was testing my 4000w generator which I have setup where I can roll it over by my loadcenter and plug it in.

Question: When testing my vents in bathrooms, heaters in bathrooms, and microwave they seem to be under powered (never really get to full speed). I check voltage and it would hover around 120v (the bathroom heater would actually make it flucuate from 95v to 125v). I tried turning all lights off in the house and trying again (fridge and stand alone freezer running) and same thing.

Any answers. Thanks
 
The voltage regulation in a small generator stinks and is largely if not entirely dependent on the mechanical governor that maintains the 3600 RPM needed for 60 Hz and proper voltage.
 
Next time available I'll run some more tests with the panel cover off so I can check things like HZ. I bet that is the problem, the hz is to low, and not only do the motors sound sluggish but are probably drawing higher current thus compounding the problem.
 
Cody when I first got my 5000 watt unit I checked it out. It was running slow out of the box.

I plugged in about 3000 watts of quartz temp lights let it reach temperature then checked voltage and frequency...it was slow.

I kept adjusting the run speed till I got it real close. On mine I have a Briggs engine and you have to move a governor spring into different holes on an arm until you get the speed you want.
 
Thanks Bob,

I bought mine the year of Hurricane Katrina. A couple of months later there was another monster called Rita that gave us a real scare, I had to drive 130 miles to purchase the generator. Well, while trying to figure out how it worked (instead of following instructions) I messed with the throttle adjustment that I later found out I wasnt supposed to touch:roll: . I really have not had to use it since; this is really the first good test I gave it.
 
I plugged in about 3000 watts of quartz temp lights let it reach temperature then checked voltage and frequency...it was slow
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I am curious, how did you check for frequency. I am going to check mine for voltage today.
Dave
 
davidr43229 said:
how did you check for frequency.
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I have a Fluke 87 DMM that can measure frequency. :)

I was once on a job where another EC was using an old Dayton 5000 watt generator, well it sounded 'fast' and the temp lights looked un-naturally bright. I had time to kill so I put my meter on it...about 140+ volts! I checked frequency and it was in the 70 hzs, that worked out to a 3600 RPM engine well into 4000 RPM. I found that the governor had been tied wide open with a tie wrap..no idea why someone would do this. I chose not to plug my tools into that generator. :D
 
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Backup generator

Backup generator

I have learned never to check out a new house except by jumping off the temp service. Even at that I only check out the light and plugs and label the panel. I then come back after the power has been hooked up after the final inspection and check out everything else. Even by using the temporary service you can get false readings sometimes. So I keep it to a minimum and don't put a big load on it. Semper Fi
 
Brady Electric said:
I have learned never to check out a new house except by jumping off the temp service. Even at that I only check out the light and plugs and label the panel. I then come back after the power has been hooked up after the final inspection and check out everything else. Even by using the temporary service you can get false readings sometimes. So I keep it to a minimum and don't put a big load on it. Semper Fi
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Why would that be? Isn't your temp service provided by the same utility company that provides the final service? Or, is the temp service you are discussing not provided by the utility company?
 
After reading this thread I decided to "tune" my Porter BSI550 5500w / 9,000w surge, and like you I had to move a governor spring into different holes on an arm until you get the speed you want or voltage. I took a 1500W portable heater in 1 phase and a 1500w hair drier in the other phase. Found out I was reading 110volts (low), vs the 123.3 utility power, so I moved the spring to read 120V under this semi loaded condition. I have no idea what Frequency I am. With no load both phases are reading 129-130V (ish). :cool: Does this sound ok? or too high for TV's & Computers.
Just my $.02
 
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A poor mans frequency meter can be a plug in analog clock, with a second hand.
If it is running slow your under speed
If it is running fast your over speeding,
If it is running just right, your running on speed,

Compare to a watch or battery powered clock,

my experience on small generators it is better to slightly over speed 61 or 62 hertz, if your setting it with a light load or no load as usually the governors on small motors are not that exact, and under load they will pull down some,

or set it running under the average load it will be expected to handle.
 
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