Generator Adjusting Help

[motorcity]

Picked up a Powermate 5000 watt generator, for $50. It has a Tecumseh 10hp. It need a new carb, so I replaced that. It now runs, but without a load it was putting out around 75 volts. So I adjusted the fast idle nut, that puts more tension on the govanor spring, to around 118volts. So I plugged my shop vac in, and the voltage drops arond the mid 90's. Should I sdjust the fast idle nut more, so it is putting out 118 volts with a load? Its almost like the govanor is not compensating for the load.

 

[JTK]

Could still be carb issues and nothing to do with the governor. Is the governor staying pegged when the machine is under load (calling for max trottle opening), but yet still struggling to maintain RPM? If so, the governor is doing it's job. Is the fuel new? How's the spark plug?

Joel

 

[boraticus]

If the engine is directly coupled to the generator, and it probably is, you should adjust the engine speed to 3600 rpm with a load. By rights, it should run at 3600 rpm with or without a load unless it's an inverter type generator. Pretty sure that one isn't. Optimum voltage should be around 125 volts.

 

[motorcity]

Joel, the plug is new as well as freash fuel.The govenor isn't pegged under load.

boraticus, I'll check the engine RPM's tomorrow and see if it is at 3600rpm's, with a load. It seems as thought the rpm's are higher without a load, currently.

 

[grcmptrnrd]

My favorite tool for checking generator voltage and Frequency/RPM is a Kill-A-Watt meter:

http://www.p3international.com/products/special/P4400/P4400-CE.html

Also nice to be able to see exactly how much load I'm putting on it when adjusting.

 

[JimPghPA]

There are three ways to set the RPM's. It should be set at 1/2 of full load (resistive heaters are a good load). Set it to 3600 RPM's which produces 60 HZ from the generator section.

BTW if you run those engines higher than 3600 RPM's for a while you drastically reduce the life of the engine. You do not want to leave the RPM's adjusted for anything above 3600.

You can get a mechanical tack and put it on the end of a shaft to get it to spin at the same speed as the shaft. On those gensets that is not easy to do.

You can get an analog 120 volt powered clock such as a bedroom alarm clock and run it from the generator (if the outputd is maintaining 120 VAC) and compare the speed of the second hand to a watch with a second hand.

You can put a frequency meter on the output. You may have to attenuate the output (divide it down to a few volts AC using a resistors, also may require some capacitors to filter noise).

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Re: the voltage not remaining constant. This is not a function of the RPM's unless the RPM's are changing by a very large amount
like going down to half of rated. If the governor is working right the RPM's will remain constant from 0 to full load.


I would suspect the capacitor inside the electric generator section is bad. Or it could be a bad diode, or a damaged winding, or worn out brushes, or a dirty comutator.

The electrical generation section of those units is very simple because there are very few components to it. You do not have to understand how they work together to regulate the voltage. Just test each component.

My bet is a bad capacitor or a bad diode.

Good luck.

 

[JimPghPA]

PS: Be sure to lube the bearing at the end of the electrical generation section with Kendall Wheel bearing grease (the red is preferred).

 

[motorcity]

I adjusted the rpm up to 3600, and the voltage is mow up to where it should be. But I haven't checked it with a load on yet. I had to put a new 110v outlet on it, the old one had a screwed up outlet. I also put some grease in the end bearing, it looked kind of dry. And also cleaned the comutator ring, while I had it apart.

 

[boraticus]

Originally Posted By: motorcity
I adjusted the rpm up to 3600, and the voltage is mow up to where it should be. But I haven't checked it with a load on yet. I had to put a new 110v outlet on it, the old one had a screwed up outlet. I also put some grease in the end bearing, it looked kind of dry. And also cleaned the comutator ring, while I had it apart.


Good going!

Don't you just love fixing stuff?!! Especially when it works as good as new.

 

[motorcity]

I paid $50 for the thing, and the carb cost me $45, I got a pretty good deal overall.

 

[JimPghPA]

The two outlets are wired so that each one is connected to one side of the 240. You will have to remove the jumper between the two sockets, or they will be shorted out.

When you load it down it is best to even out the load. The total load should be about 1/2 of the rated output. And each socket should get 1/2 of that load. About 1/4 of full load for each socket.

What brand of engine and HP does your gneset have? Coleman made them with Tecumseh, Briggs & Stratton, Honda, Robin, and I think some Chondas. Also, some had 10 HP and some 9. Some engines had iron sleeves, and some aluminum sleeves.

Regardless of the make of engine GC is a very good oil to put in an air cooled generator engine. One of the problems with a generator is usually when you put oil in it you do not know what the ambient temperature will be when you run it. GC will provide the good cold weather flow, while not shearing to too low of a viscosity in hot weather.

I keep GC in mine. I also stock many quarts of GC, and two quarts of M1 V twin 15W-50 for the hottest days.

Shell Rotella (any of the JASO-MA rated ones, which would be all but 10W-30). M1 Delvac, M1 0W-40 are also good oils. For warm temperatures Castrol HD 30 SL rated (hard to find now, Castrol went to SM), and PY HD 30 SL rated are good oils.

For some good tips about air cooled gensets google "BITOG generator JimPghPa".

 

[motorcity]

The Generator has a Tecumseh 10hp. Right now I have Penzoil SAE30 in it, with a Little MMO mixed in, to flush the motor out. I'm going to put Shell Rotella 5w-40 syn in, after flushing the motor out. Right now the generator is buried, I'm re drywalling my garage. After I'm done I'll have to check it with a load to see how it runs.