MEP 802A Load Issue

[csmitty]

So with the forecast for outages here in ATL I got the 802 buttoned up and connected to the subpanel to test it out. Warmed it up and closed the contactor and verified power at lugs and subpanel, right on 240V.

Largest load I had in the garage is a 30gal air compressor. Tag says 15A at 120V so I turn it on (connected through my cable reel) and it really bogs the 802. Hz meter bottoms out and starts pumping black smoke, doesn't stall though. Flip it off and goes back to normal. Try a few other loads, smaller air comp, table saw, and it operates fine.

Any thoughts on it bogging down with the 30gal comp? Only thing I can think of is voltage drop on the long run.

 

[Grizzlypower2001]

Keep an eye on the hertz, bring it up couple points and try it again I had the same issue. Mine ran no problem 26 amps soon as I put like a 32 amp load on it the frequency drop down and it did the same thing that fell flat on its face.

Sent from my XT1254 using Tapatalk

 

[Kenny0]

Compressors can be very hard starting requiring 2 to 4 sometimes more amps to start. It seems like it should start this load though. I would replace all fuel filters and check air filter. I would also add more and more smaller loads to capacity to see if the generator will output what it should. What size of wire and how long of a run is it?

 

[Kenny0]

So with the forecast for outages here in ATL I got the 802 buttoned up and connected to the subpanel to test it out. Warmed it up and closed the contactor and verified power at lugs and subpanel, right on 240V.

Largest load I had in the garage is a 30gal air compressor. Tag says 15A at 120V so I turn it on (connected through my cable reel) and it really bogs the 802. Hz meter bottoms out and starts pumping black smoke, doesn't stall though. Flip it off and goes back to normal. Try a few other loads, smaller air comp, table saw, and it operates fine.

Any thoughts on it bogging down with the 30gal comp? Only thing I can think of is voltage drop on the long run.

Also if possible plug the compressor directly to the generator, if that works okay probable voltage drop.
Do not use the convenience outlet for this, too much load
One more thing, if you already have a good load on the generator might not be enough surge capacity left to start the compressor

 

[csmitty]

Keep an eye on the hertz, bring it up couple points and try it again I had the same issue. Mine ran no problem 26 amps soon as I put like a 32 amp load on it the frequency drop down and it did the same thing that fell flat on its face.

Sent from my XT1254 using Tapatalk

So you bump it up to start with to anticipate the slow down.

 

[csmitty]

Compressors can be very hard starting requiring 2 to 4 sometimes more amps to start. It seems like it should start this load though. I would replace all fuel filters and check air filter. I would also add more and more smaller loads to capacity to see if the generator will output what it should. What size of wire and how long of a run is it?

That's a good point. I should put a meter on it when running off the grid and see. It's not a critical load just the largest I had that would work the gen some. All fuel filters are new. I'll have to double check the air but I believe it's recent as well. I did run a small pancake Compressor and started the table saw, the starting current of that peaked it around 50% with the small comp running then dropped down as expected.

The run is about 25' of 12ga Romex to the reel then probably 80' of 10ga SO cord.

 

[Kenny0]

With over 100 feet cable the 12ga is definitely too small. If it was mine with that long of a run, I would go with 8ga the whole run. The bigger the voltage drop the longer it takes to start and will bog the generator even more. Even with 10ga the whole run, I think your pushing too much current.The longer the run the larger wire size you need. Too much current for too long will heat the wire up too much, enough to melt the wires together and short out or even start a fire. Nothing to mess with, go with the 8ga.

 

[Guyfang]

Have you ever had this gen set up to rated load before? And ran it for extended times?

 

[csmitty]

Have you ever had this gen set up to rated load before? And ran it for extended times?

I haven't. I got it May last year and just went through it slowly. Put new injectors and new return line on it and all new filters. Engine looked in good shape though a compression/leak down wasn't done it. It was borescoped. I've just exercised it with no load occasionally so just now starting to add some load. Been being to put together a load tester just hasn't been high on the project list at the moment.

 

[Guyfang]

You do have a problem with voltage drop. KennyO's post is spot on. Your cable is too small/too long.

You can also try to put a smaller load on it, and run it a while. Do you get carbon chunks flying out? If so, it's a wet stack problem. Lots of threads on that here. Continue to add load, if there is no wet stacking problem. If you do get chunks of carbon comming out, then follow instruction in the threads for solving this problem.

Do you have any sign of fuel leaks/seeps on the engine. Lots of threads here discuss how the rubberized fuel lines have pinhole leaks. You can barely see them, if at all. But the fuel system no longer has the PSI pushing the fuel provided to the IP's, and the engine speed/hertz falls off.

These are three problems that are common. So start looking here.

 

[csmitty]

You do have a problem with voltage drop. KennyO's post is spot on. Your cable is too small/too long.

You can also try to put a smaller load on it, and run it a while. Do you get carbon chunks flying out? If so, it's a wet stack problem. Lots of threads on that here. Continue to add load, if there is no wet stacking problem. If you do get chunks of carbon comming out, then follow instruction in the threads for solving this problem.

Do you have any sign of fuel leaks/seeps on the engine. Lots of threads here discuss how the rubberized fuel lines have pinhole leaks. You can barely see them, if at all. But the fuel system no longer has the PSI pushing the fuel provided to the IP's, and the engine speed/hertz falls off.

These are three problems that are common. So start looking here.

Yea the long cable voltage drop is what I was figuring, I can try a shorter cable. Not necessary to run though. I did add some small loads and it handled them just fine. When I turned on the compressor though I just had black smoke which I would expect from a large load. No chunks or anything. I pulled the muffler and exhaust manifold when I got and it was pretty clean granted I couldn't see in the muffler. I borescoped around the exhaust valves and they looked pretty good as well. So no real wet stacking issues from previous use, maybe just my few exercises.

After running it for 20mins with some small loads I shut it off and checked around the top of the engine as I did have some leakage from the return lines before I replaced them. Was dry up there. I did not go over the bottom closely but I was looking for a dropped nut (hate those things, rivet nuts were planned but hadn't gotten to it yet) and didn't notice anything out of the ordinary. I'll look again though.

 

[csmitty]

Wondering if this loose wire which I think goes to the pressure sensor could be an issue with putting a large load to it? Or maybe with the fuel gauge not working. Ran for 7 hours and didn't move, granted below 50% load.

Sorry it's blurry. It was running.

 

[Zed254]

My 802A has 3 wires coming out of that item. One is disconnected. The other 2 run the oil pressure gauge. I've had to repair one of the wires twice due to the vibration of this machine and tight zip ties. I now have a longish pair of wires that are free to vibrate (cut some zip ties) and my oil gauge works fine.

 

[Bmxenbrett]

Useing a air compressor or any electric motor is not a good load test. Do you have a electric stove or hot water heater you can properly load test is?

If you put new/used injection pumps in could you have clocked them wrong? Turning them in the block is basicly there fuel adjustment.

 

[Guyfang]

Zed, have you looked the vibration dampers? There are four of them, rubber baby bumpers. If they are too hard or cracked, the set can vibrate. Also, as Bmex just remined me, you can adjust the injectors a tad, N smouth out the set. When they are too far out of adj, the eng can vibrate.

 

[Zed254]

Yes sir. I've been soaking up info from this site: I've adjusted the injectors and lubed up the isolators - they are in good shape. One seemed to be more compressed than it's matching unit so I tightened them all as much as I could - tough getting a wrench on the bottom nut. Vibration has improved a LOT. I think it is now all me: wanting a 2 cylinder to purr as smoothly as the 4 cylinder. But it was a jumper when I first got it.

 

[csmitty]

Useing a air compressor or any electric motor is not a good load test. Do you have a electric stove or hot water heater you can properly load test is?

If you put new/used injection pumps in could you have clocked them wrong? Turning them in the block is basicly there fuel adjustment.

I will most likely build a dryer heater element tester soon to run it more continuously with a full load. I did remember I had a 1500W garage heater so used that for a bit. I was able to get it up 75% with the oven on 350. I didn't do anything major to the engine, just replaced injectors and return line, along with filters. I probably will add a fuel pressure gauge to see if the pump is having issues.

Zed, have you looked the vibration dampers? There are four of them, rubber baby bumpers. If they are too hard or cracked, the set can vibrate. Also, as Bmex just remined me, you can adjust the injectors a tad, N smouth out the set. When they are too far out of adj, the eng can vibrate.

How much vibration would you expect to see from the 2cyl? I noticed the engine does vibrate (obviously) but its not jumping all over the place. I also only have two on the engine feet, the side towards the radiator. Then two on the gen housing.

 

[Bmxenbrett]

I had a 802 that would move about 4 in across a concrete floor in about 15min. They do vibrate more than the 4cyl but as long as you can load it to 5kw i would call it good.

 

[jamawieb]

I've had some that would vibrate like crazy and then some that would just vibrate a little.

 

[Zed254]

For typical vibration performance you can compare the run movies on GovPlanet sales: MEP802A vs MPE803A. I've been able to get my 802 to where it compares nicely to most of those I've seen for sale. Just watch the oil cap chain jump around. The 803 has always run smoothly with very minor vibration.