generator start under load

Shutting a loaded generator is not only bad for the generator for the reasons stated,it is also bad for the motor. Loads should be removed and gen allowed to run until engine temperatures stabilize. This only takes a few minutes.

although we are getting off topic, i picked up a WEN inverter, the generator doesn't care about the eco switch, it revs up to a certain point, light goes green then revs back down and turns on the power.

thus this discussion is more around non inverter generators.

boy that Pinella guy is making a fortune, there is prolly 30 bucks in parts for that remote start kit, thats quite the markup

Hi,

My Yamaha 3000 Sieb when new did not "like" to be loaded. It would sometimes flip the internal breaker which mean starting it over again. After 20 hours run time that was much less of a problem.

Now that I use it with the Magnum inverter, power is not turned on inside the RV for some time. I know it is a short time--but it seems as if it is ages.

I think I can safely say that starting an inverter generator should be done with the economy switch turned off.

My own procedure is to have no large loads turned on, start the generator, wait for the Magnum to allow pass through, turn on load support on the inverter, then switch the generator to economy mode, and turn on large loads such as the air conditioner. This is easy as pie for me as I have a Pinella remote start for the Yamaha. The Pinella allows me to move from regular to economy modes remotely.

Shut down is:

remove large loads
set economy mode off on the inverter
shut down the generator

I know of no standard voltage regulator (non inverter type generator) that likes to push a field when the generator is operating slower then 55 Hz. This is referred to as the "Cornering Frequency". Starting up under load can push power transistors well beyond their limit. Via inductance, a fully saturated stator can actually pull more amperage through the rotor coil than what a simple ohm resistance test would imply. Will the engine start? More probably if it has excess horsepower to wattage ratio. I've never had an opportunity to fiddle with an inverter generator to see it's loaded start up characteristics but judging from the large amount of troubleshooting questions and answers full load starting probably isn't very wise either.

When frequency hits 55 Hz conventional voltage regulators go nuts.

It's just as bad to shut them off under load- both times, as the genset is running slow, the voltage regulator is valiantly trying to maintain 120 volts, which it does by boosting the voltage it sends to the rotor. This is not good on the voltage regulator.

thanks matt, kind of what i was looking for.

Bill,

To me, this is more than a hypothetical question. The answer is that it will probably start and cough off very shortly there after. This is why emergency generators have a load-delay. The diesels are kept warm and do not have much problem but still need 15~30 seconds to get the lube oil up. Most spark ignition engines need a moment to get the mixture right.

There was a time that I watched a fellow camper at a rustic campground beat himself up trying to run a generator. He would rip the rope and it would fire and run a bit, stumble and then die. Finally, I had to go see what his problem was. (I am a ship's engineer by trade as so well versed in engine stuff.)

When asked if it was unloaded and he said it was and the breaker was visibly open. I touched it and the toggle was loose. He said it has failed and was not common breaker, so a "friend" had by-passed it. He said everything inside the trailer was off. I suggested that he unplug the shore power cable and try. This resulted in a running machine. He didn't want to reconnect it hot. (There is some possibility of damage is there is some load.) Well, there was load. When he restarted, the engine - now warm - bogged until it could catch its breath. I suggested that he go inside and see what was on that should not be.

He was kind of embarrassed when he came back out. The water heater was on..... It was a 2K machine and the heater was 1.5, but more than the cold machine could manage without a running start.

There you have a definitive case.

Matt

I been starting my eu1000 under full load of my pd9245 for 4 years, never hurt anything yet. I do have a little trouble in real cold temps,....gotta be quick w/ the choke adjust.
No, I didn't say it is correct,.....just that it don't hurt a thing.
And its a lot better than burning up the receptical from plug and un pluggin.
And yep you can use a switched strip inline, if you think you need to.

Oh yeah, I stop it under light load too, or let it run outta gas.

Starting a generator at full load can cause problems.
A generator starts producing current as soon as the engine starts turning, does not care what RPM it is turning at. Without a load it comes up to speed quickly, with a load it takes longer to get up to correct speed.
Remember, the gen 'SET' is two half's, engine and generator. With a generator the engine is set to run at one speed to produce current. With a inverter type of gen set the inverter is set come up to the needed RPM before it starts producing current, hence to large cost difference between a generator and an invertor.
Here is where the problem comes in, when a generator is trying to produce current at a slow speed it can burn out one of the diodes (usually three diodes in a gen set). When this happens the generator then only produces partial current possibly damaging whatever appliance or electronic device you have hooked up. The engine will come up to normal operating RPM producing only partial current so you may not realize that you are damaging your electronics. This process only takes a few minutes to happen.
Remember to either trip the breaker on your generator (or invertor) or unplug the load before starting the set. Can save you some money and headaches.

There's only one way to find out if it will work or cause damage to the generator.
Borrow your buddy's generator, load it up and then start it. :B