Mep-803a Fuel or Electrical problem. Will Not Trip.

[mt4x4]

I have had my mep-803a for about 2 weeks. I got it from government auction with about 2000 hours on the meter. I have been reading here all the posts on cleaning and testing. So far i have changed the oil, oil filter, air filter, and the big fuel filter. I have also been cleaning the switches.

The first problem i had was the set would bog down the engine to maybe 800-1000 rpm's with about 43 amps from my clamp on meter(gen set on 120/240). i started checking fuel and found the lift pump was bad. I found the lift pump and aux pump had the same part number (E-1074) so i swapped and got one on order. The aux pump in the lift pump location now pumps fuel. I have replaced all the return lines with the correct tubing. I now get fuel flow back to the tank. This all made no change. I noticed the fuel cut off solenoid looked new. After a closer look i found the linkage was mounted in the top hole. I moved it down the the bottom of the top 2 holes and now i can go above 43 amps.

The problem i have now is i can still bog the engine down to 800-1000 rpm's (i'm guessing rpm from sound) at about 56 amps. The engine runs just fine adding in amps slowly until i hit that 56 amp point and than just drops in about one or two seconds. If i disconnect the load it will come right back up. I start getting some black smoke around 52 amps or so. When the engine drops its still producing black smoke.

I would hope i should get an overload fault before the engine bogs down. Should i be looking for more fuel problems or problems with the set not faulting?

 

[Daybreak]

Howdy,

I would suggest you run your unit for 3-5 hours at around 45 amps load. Meter should be around 80% or more. You need to clean it out.

 

[69birdman]

You may want to change the fuel filter too. I just did my first major service on mine and look what I found. Looks like original filter.

 

[Light in the Dark]

What have you done to the machine, be specific. I would definitely recommend replacing the in line fuel filter, as well as draining the water separator, before anything else. Are you running on old fuel? Have you put any Seafoam through this?

 

[Zed254]

Read up on wet stacking. It takes time at higher load to clean out the exhaust system if your machine was run for long periods of time at low load. Your machine is rated at 52 amps max, not 56 amps. PUSH RESET TEST LAMPS button will confirm all of your trouble light bulbs are working.

 

[Ray70]

Also, keep in mind that the overload on these machines do not trip off immediately. Once an overload is applied, it will bog the motor and it will start to chug black smoke for a short period of time before tripping the overload. It doesn't react instantly like the circuit breaker on an 003A. The time delay depends on the amount of overload. The overload also tends to trip slower when progressively adding higher and higher resistiance loads. An immediate inductive load like a large motor will tend to trip it faster. Once you get the carbon burned out of the muffler, load the machine up until you get to about 133% on the meter. It should hold that load for a few minutes before tripping the overload. If you apply a hugely oversized load the short circuit light should come on and the load disconnect almost immediately.

 

[mt4x4]

I have read about wet stacking. The trouble lights are working. I'm running new fuel. i had drained the water separator. I replaced the fuel strainer at the pump. I will replace the inline fuel filter and run the load test at 45 amps for 5 hours and report back. I understand the unit is rated at 52 amps. I want this thing to trip, i just can't make it. I would like an idea of how many amps will for sure cause a trip. If i run 54 amps for an hour, will it trip? How many amps will cause a trip in a matter of seconds?

 

[Light in the Dark]

Get some real high quality fuel system treatment in it (like only put a couple gallons in the day tank, but an entire can of Seafoam) and burn it through. This machine should not be bogging down below its 100% rating... so we need to clear that part of this up first. This machine is rated 52A @ 100%.... I routinely test them up to about 62A and they hold steady, but I dont do that for long.

I think you need to get the engine squared away first, before we troubleshoot the rest. If its been 'stacked, its time we clean it out and get a good baseline.

 

[Daybreak]

Howdy,

You can watch a few hard runs here [FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]MEP-802A/MEP-803A units on a military surplus load bank[/FONT]

You want to ensure everything is working and running to the best ability before raising above 100%. You need to monitor and watch for any problems, and be prepared to take action if you do have issues.

 

[mt4x4]

At this point i can hold 52A no problem. Before i fixed the fuel cut off solenoid it was a problem. So i should be able to pull 62 amps without the engine dropping? How long should it do 62 amps before a trip? I will add seafoam to my tank on my test this weekend. I just ordered some dryer elements to build a more proper load bank.

 

[Farmitall]

Maybe its just me, and maybe I just don't get it, but why are some people always trying to push their generators to the breaking point?

I understand that these sets are rugged but why purposely try to break them? I see this same mentality with side by side owners too. They buy a vehicle for $15-$20k then take it out to try and deliberately punish it to the breaking point....and usually break it. Then they weep and complain when they are hit with a $2000 dollar repair bill at the shop.

Sitting here scratching my head.

 

[Light in the Dark]

The MEP-803A has a prime designation at 10kw @ 80% PF. The prime designation means designed for 24x7 use. These machines are capable of more than that (most government products are designed for over stated capacity, that sometimes gets whittled away through the contracting process) for use other than 'prime'. As I go through many units, I need to make sure that they will put out what they say they will, and then some. Most civilians will never use these as they were designed, for anywhere near the hours. I can't speak for others, but when I ramp them up its for testing purposes only, and within their stated capacity (the engine lister petter builds for these is rated for a maximum of 17kw based on HP produced). The controls in place are what put the limits on the output, and for good reason. The output gauge goes to 133% for a reason...

 

[Farmitall]

The MEP-803A has a prime designation at 10kw @ 80% PF. The prime designation means designed for 24x7 use. These machines are capable of more than that (most government products are designed for over stated capacity, that sometimes gets whittled away through the contracting process) for use other than 'prime'. As I go through many units, I need to make sure that they will put out what they say they will, and then some. Most civilians will never use these as they were designed, for anywhere near the hours. I can't speak for others, but when I ramp them up its for testing purposes only, and within their stated capacity (the engine lister petter builds for these is rated for a maximum of 17kw based on HP produced). The controls in place are what put the limits on the output, and for good reason. The output gauge goes to 133% for a reason...

Ok, thanks I get that, and know your operation purposes with the testing and all but as you state, its the controls that put the limits on the output.....and thats what a lot of people try to push( and frequently break) instead of operating the sets with a comfortable margin of reserve capacity so it will basically run forever.

My mindset is that if I can get a constant 80% out of it without pushing it and know beyond any reasonable doubt that it will continue to perform without malfunction then thats how I'll run them. I'd rather have an extremely reliable 80% than an iffy 100-130% with the constant anticipation of a breakdown. Just my 2 cents.

 

[jamawieb]

I personally load test these at 56 amps (13,400 watts) continuously for at least 6 hours before I sell them. The main reason I test them that hard is because if a problem is going to surface, it will show with a hard run on the machine. This way I can guarantee someone a quality machine with no problems. I've sold over 350 803a's and 802a's and I've never had a person with a failure. I've had one person where the fuel pump failed after about 40 hours of use but that is the only problem I've experienced with a customer and I sent him a new one free of charge. I have one customer that just logged 19,000 hours on an 802a and a couple of other guys have logged over 10,000 hours on my machines with no problems, so I say the testing proves the point.

 

[jamawieb]

I will say, every machine is different. I have some that will do 62 amps and above but then I have other machines that max at 58amps before the motor bogs down. So your machine may not do 62amps or it might do 65amps so don't push it to 62 amps if it won't but at the very least it should do 56amps. Everyone is right, you need to get the wet stacking out before pushing that hard.

 

[mt4x4]

Maybe its just me, and maybe I just don't get it, but why are some people always trying to push their generators to the breaking point?

I understand that these sets are rugged but why purposely try to break them? I see this same mentality with side by side owners too. They buy a vehicle for $15-$20k then take it out to try and deliberately punish it to the breaking point....and usually break it. Then they weep and complain when they are hit with a $2000 dollar repair bill at the shop.

Sitting here scratching my head.

I have no plans to run this at max all the time. My problem is if my wife turns too many burners on at the same time the water heater is calling for heat our generator better fault before the engine drops and gives my house 35hz. The generator faults to protect it and right now i'm only trying to test the faults to make sure they will do there job if needed.

 

[Light in the Dark]

Ok, thanks I get that, and know your operation purposes with the testing and all but as you state, its the controls that put the limits on the output.....and thats what a lot of people try to push( and frequently break) instead of operating the sets with a comfortable margin of reserve capacity so it will basically run forever.

My mindset is that if I can get a constant 80% out of it without pushing it and know beyond any reasonable doubt that it will continue to perform without malfunction then thats how I'll run them. I'd rather have an extremely reliable 80% than an iffy 100-130% with the constant anticipation of a breakdown. Just my 2 cents.

Some customers that are using this for large draw applications require huge LRA to get the machine up and going, so at least the units I sell, I try to make sure it will do exactly what they want. The inrush capability is sometimes what makes or breaks the sale. They will consume much lower power during use, well within the 803s capability.

 

[mt4x4]

last night i couldn't help but try some more. I don't have my load bank yet so i was still using the house. I put some seafoam in and got it up to 59.7A on one lag and 60.4 on the other. It was blowing some carbon out but not a lot. About 117% on the meter. After about 20 minutes something in the house kicked on and and caused the engine to drop. I was looking at my clamp on meter before i disconnected the load. 71 amps. It probably was one second before i disconnected the load. i'm not sure if it was 71 on both lags as i was using my house with both 120 and 240 loads.

Once the engine drops it will blow the fuse on the quad winding if i leave it there for more than one or two seconds. That does not surprise me as i have a fast blow fuse in there and the the rpm being so low.

 

[Light in the Dark]

Even if you can safely load it up to 80+%, just let it rip for a few hours straight at that. Its loaded enough to get burning up the gunk. You can step up from there after you really give is a nice warmup.

 

[Daybreak]

Howdy,
Let's get a few things straight. Any running over 100% is not what I do for a long time.

The over 100% is in a very controlled situation, and for final testing purposes only. I am using a military load bank.

It is not wise to use your house as a load bank. As you know, things can go bad, and things can get zapped. After you have a correct operating unit, now connect your house and carry on.

The best thing you can do is to stop pushing it. You need to follow a course of action. Run your unit at 100% for four hours. Monitor it the whole time. Check the oil level, listen to the sound, watch for problems. Watch oil pressure, coolant temp, hertz, voltage.

Wet stack correction is not just black soot specs flying out. Some will be the black smoke, some will be the dissolved soot from the muffler, some will be the soot from the cylinder walls, piston tops, and valves. In other words, some are worse than others. What you want in the end is a correctly functioning unit which you know you can depend on when you need it.

The military MEP generators are overbuilt. They demand 24/7 100% operation.