MEP 803a when does the overload kick in? Motor bogs down big time when overloaded.

So pretty much wrapping up my process of getting the 803a going. Had it running on the load bank the other night and it will handle no problem 13500 watts resistive load. Throws the percent load meter to a little over 100%. My load bank is simply 6 4500 water heater elements I built it to load up my 005a wish I had smaller steps now between elements. Any way three of them were switched on and just to see what she would do I threw on the switch for the fourth one. I believe that is around 16000 watts or so, way over what the unit is rated for. Well as you can see in the first video the one filmed at night the motor just starts to bog down pretty much just a givn er but just dosent have the poop to do it. Well I did not leave it in dropped off one 4500 element and it sort of recovers but not really till I dump more load off.

So the next day I tried this one more time with the forklift charger running so a little less than 16000 watts 3 elements and the forklift charger comes out to more like 14k somethin. Any way I found the generator will do it if I throttle it up to full throttle and then drop it in however you can see the exhaust it is really workin hard to do it. As soon as I throttle down a little to bring it into 60hz the motor just starts to bog so I drop an element again to lighten the load.

Couple questions bout all this why is the overload not kickin it and opening up the contactor? I performed the test procedure as it is outlined in the TM for the over current/ short circuit relay seemed to test okay on the first test however the #2 terminal and #3 terminal on the overload relay just threw the short circuit light as soon as I closed the contator. Perharps this part is bad? Not to worried about it never going to be pushing this thing this hard at the house was just curious at what point they usually open up. From the reading on here looks like around 13000 watts or so.

The other thing is if the motor can keep up with the load put on it when you manually throttle it why is the governor not asking for full throttle and allowing the motor to keep up instead of bogging down?

Attached are the first and second videos so you can see what I am talking about.

https://youtu.be/i80uZSanc7o
https://youtu.be/cR1DhfWZPdE
Lee

What does the exhaust look like? If it has trouble recovering, you might want to run some Seafoam through the set, and let it rip at full rated load (or close to it) for a few hours. Will help clean up the entire combustion system. Then retest and see if she takes the load better.

The stator is 12KVA or 12 x .8 is approximately 10kw. Now that is 12000 watts. I assume you are checking current via an amp meter. The meter on the unit may be off. 16k is way too much of an inductive load to run on a 10k generator. You can damage the stator. Just because it is military grade doesn't mean it will do impossible things without damage. Your battery charger test is more practical for a 804 not an 803.

Light in the Dark said:

What does the exhaust look like? If it has trouble recovering, you might want to run some Seafoam through the set, and let it rip at full rated load (or close to it) for a few hours. Will help clean up the entire combustion system. Then retest and see if she takes the load better.

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I'll. Have to do that exhast slight black color to it at full load and then over full load blowing lots of black smoke can see it in the second video.

Hard Head said:

The stator is 12KVA or 12 x .8 is approximately 10kw. Now that is 12000 watts. I assume you are checking current via an amp meter. The meter on the unit may be off. 16k is way too much of an inductive load to run on a 10k generator. You can damage the stator. Just because it is military grade doesn't mean it will do impossible things without damage. Your battery charger test is more practical for a 804 not an 803.

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Current is being checked on clamp on amp meter. I figured 16k was way to much so why is the overload not kickin out the contactor? This was the question I had in mind and then wondered if it has to be loaded even higher for the overload relay to disconnect the contactor. Should it not be protecting the unit from overloading?

Yes 16 is too much to ask of this genset. While Lister does rate the LPW4 for 18.7kw @ 1800rpm, thats not going to work in these sets (http://www.lister-petter.com/p/power-water-solutions/4/lp-range/1/engines/16/lpw4). You could always wire the elements differently. For example my load bank has (4) 5400w elements, but two are wired together in such a way as they draw 2700w. So I have a bank of 5400, a bank of 5400, and a bank of 2700 (giving me the range of 5.4, 8.1, 10.8, and 13.5kw).

leedawg said:

I'll. Have to do that exhast slight black color to it at full load and then over full load blowing lots of black smoke can see it in the second video.

Current is being checked on clamp on amp meter. I figured 16k was way to much so why is the overload not kickin out the contactor? This was the question I had in mind and then wondered if it has to be loaded even higher for the overload relay to disconnect the contactor. Should it not be protecting the unit from overloading?

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How long were you overloading in this manner? The set does have burden resistors, to do the heavy lifting. Seafoam is excellent stuff, if you have never run it. Just dump a whole can in the tank and give it ****.

Why must everyone just has to max overload these sets? Be happy they work!

I am happy it works. I've put the issue to bed was just wondering why it did not trip out. Only ran it that way for bout a minute. Thanks for the responses.

Mine dosnt trip either..its really not a problem to me.

Dumping 16k or 12k on a 10k set is not a good idea.

I agree that 16kw is way to much for these machines. I load test every unit I sell at 14kw for approximately 30 minutes and then set it to 12kw for an extended period (minimal of 6 hours) to make sure everything performs perfectly. The only reason I do that is because I want to make sure the person buying it doesn't have any problems. If a problem should come up, it will be within that time period I stated. I've sold hundreds of these units and never had a failure that stopped operation. I have one gentleman that has logged 13,500 hours on his 802a and the only major issue he has encountered is the battery alternator failed at approximately 12,000 hours but he had it rebuilt locally for under $100.

My 802A will just bog down instead over tripping at overload. If I run it over 100% it will overload somewhat randomly. My best guess is if it's way to much, the engine bogging down is your overload signal.

jamawieb said:

I agree that 16kw is way to much for these machines. I load test every unit I sell at 14kw for approximately 30 minutes and then set it to 12kw for an extended period (minimal of 6 hours) to make sure everything performs perfectly. The only reason I do that is because I want to make sure the person buying it doesn't have any problems. If a problem should come up, it will be within that time period I stated. I've sold hundreds of these units and never had a failure that stopped operation. I have one gentleman that has logged 13,500 hours on his 802a and the only major issue he has encountered is the battery alternator failed at approximately 12,000 hours but he had it rebuilt locally for under $100.

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You would have been welcome in my shop!

I’m doing a load run on my 803a right now. Running my house it barely works unless the hot water heater is going. Even my heat pump barely puts any load on it. I usually just load it to 75-100 percent for an hour or two every once in a while to combat wet stacking. I have had it loaded to 100 percent and had the water heater kick on. All the lights in the house dimmed and the generator started cranking out black smoke. I was able to turn off my dryer before it tripped any breakers. All that being said, I can’t load it much without intentionally putting extra loading on it. The 803a is more than enough for my house and it always fires up when I need it. Definitely would have been fine with the 802a though. It would still get the job done while burning less fuel and wet stacking less.