MEP-005a First run on Load bank with smoke

[bosko]

Hi,

I got around to getting a home made load bank setup with some parts that were laying around. I have eight 240v 1ph 3,800watt water heater elements. I have 4 breakers wired to a pair of elements, so one of the legs is a little lighter than the other two. When we ran the engine unloaded it made some white smoke. Today I put it under its first load for a little over an hour running all 8 elements. The smoke lightened up a little bit but there is still smoke. I took a video, its hard to see it in the video but does this look normal? Do I need to put it under more load or just run it longer? Please see video.

Thanks

http://www.youtube.com/watch?v=clGMUpeHob8

 

[1800 Diesel]

Hi,

I got around to getting a home made load bank setup with some parts that were laying around. I have eight 240v 1ph 3,800watt water heater elements. I have 4 breakers wired to a pair of elements, so one of the legs is a little lighter than the other two. When we ran the engine unloaded it made some white smoke. Today I put it under its first load for a little over an hour running all 8 elements. The smoke lightened up a little bit but there is still smoke. I took a video, its hard to see it in the video but does this look normal? Do I need to put it under more load or just run it longer? Please see video.

Thanks

First--my comments are generic in nature as related to the oil burning...I have not dug into the TM to review the specifics of the 298 engine. Obviously, the blue smoke indicates oil being burned.

From an engine that's been sitting up for years, surface rust on the liners may be causing a sealing problem and the rings may need to seat a little longer through some good hard running. Other reasons--the oil or compression rings may be partially collapsed--again from not running. As to the amount of smoke, I've seen much worse than that amount on many different types of generators. The oil burning isn't really hurting anything though but you'll need to watch the dipstick level pretty close. Another possibility--valve stem seals could be worn (or brittle/dried out) and allowing oil to be drawn into the cylinders. If the oil burning continues as is, or it gets worse, you'll need to do a compression test to help isolate the problem. In the short term, I would continue to run it as much as possible to see if it clears up. Also I would load the unit up to at least 75-80% for another hour or two to help clear some of the oil burning.

I assume you're just running clean diesel with no additives? On our start-ups we use O/B motor oil for lubricity & also diesel additive (injector cleaner), so our 1st-time start ups tend to show a little smoke too--but not as much as in your video....I'm sure other fellows on here will come up with additional causes and suggestions as well.

Keep us posted...

Kevin

 

[Stalwart]

Myself I'd run it another hour or two and then give it an oil and filter change and call it good. A small amount of smoke for such an old Diesel design is normal, most old Diesels ALWAYS smoked at least a little at ALL times. When I was a kid I serviced numerous Allis-Chalmbers heavy equipment Diesels and if they weren't smoking a bit they weren't running, and those had a turbocharger that cleans things up quite a bit. Same engine they put in some of the 70's and 80's 60KW Mil Gensets.,

 

[Harleyd315]

Take a look at the muffler and check for any signs of previous wet stacking. Some tar like drips or a black line from the muffler flange. It takes along time to burn off residual oil that may have accumulated in the exhaust system. I have an 005 that smoked lightly for almost a day before it cleared up and it still isn't perfectly clear. These are older engines not like the new clean burning diesels of today. I would run it at 80% load for a good 4-8 hours and check oil consumption before I was worried.

 

[1800 Diesel]

Take a look at the muffler and check for any signs of previous wet stacking. Some tar like drips or a black line from the muffler flange. It takes along time to burn off residual oil that may have accumulated in the exhaust system. I have an 005 that smoked lightly for almost a day before it cleared up and it still isn't perfectly clear. These are older engines not like the new clean burning diesels of today. I would run it at 80% load for a good 4-8 hours and check oil consumption before I was worried.

Now that's a good point--it seems like every MEP4 I get in shows signs of wet stacking on the manifold--some worse than others. Definitely would be easier to burn off old oil residue than to go into the engine...

 

[sewerzuk]

This looks pretty normal to me...those engines typically smoke a little.
The wet stacking that Harleyd315 mentioned is very common with these sets; I have load tested a few that took several hours under full load to "clean up." I would run it under 100% load for a few hours...I will bet that at least some of that smoke clears up.

Edit: I can't tell for sure, but it looks like your % current meter is reading around 75%...do you have a clamp on meter to see how much current you're actually sending through those elements? Assuming that the elements actually pull 3800W at 240v, you should be right at 100% load. Being a purely resistive load, you can "fine tune" current flow with your voltage. A higher voltage =more current flow =more load.

 

[M35A2-AZ]

I like your load bank!! I need to billed something like that for my mep-005a.

I think the smoke is ok.

 

[glassk]

View attachment 418505I was wondering, you don't have the load selector anywhere , i see it in the manuals , looks like it part of the genset, or maybe just the presice, any way been reading about them, lot of good features, lot of relays it seems,...

 

[bosko]

Thank you for all of the great replys.

I was going to tinker with the generator today but got called away just after I fired it up. I poured a bottle of some Lucas Diesel fuel cleaner in to the tank, Hopefully tomorrow I will be able to let it run for several hours.

sewerzuk, Good eye....

I did not have the voltage up enough it was about 208 leg to leg, I adjusted it up to 240-250ish. I will pull out my Ammeter/multimeter tomorrow to check voltages and amp draw. I notice that when I apply load in 7,600kw intervals the Hz does not adjust its self back to 60hz, so I bump up the throttle. Am I not patient enough or is that how it is? How many amps should I be able to pull from each leg?

I am thinking the cooling system thermostat maybe stuck open, I have to close the louvers nearly all of the way for it to build any temperature or are these naturally cold blooded? ambient temeprature was in the 60s today.

I also have 2 or 3 tiny coolant links from the head gasket area, it seemed to stop after i closed the louvers and got it up to 140F.

I do have the tar like drip marks coming from the muffler flange.

Here is a quick pic of it running at 240ish with 30,040hw worth of 240v 1ph elements.

<a href="http://tinypic.com?ref=1zf0cb6" target="_blank"><img src="http://i50.tinypic.com/1zf0cb6.jpg" border="0" alt="Image and video hosting by TinyPic"></a>

 

[bosko]

Thanks or all of the great comments, sorry for taking so long to get back on here.
1800 Diesel - I was running straight diesel, so I added 100 gallons worth (whole bottle) of Lucas Diesel fuel system cleaner to a full tank.
Harleyd315 – I do have some tar dip marks coming from the muffler/header flange.
Glassk – I don’t think I have that panel on mine.
Sewerzuk – You are right, I had the voltage set to 208, So I probably was not getting the full 3,800w*8 elements=30,400 kw as they are rated at 240v. When the voltage is at 208 the load meter reads ~75%, when its at 240 it reads ~90%.

Today I let the generator run for about 2 hours with some load. The smoke is over all is much less, I think it must have just needed a work out to clear the pipes. I adjusted the voltage knob on the panel so I was getting 240v output. I let the generator warm and applied load little by little. Once I turned the 4[SUP]th[/SUP] pair of elements on the generator started to fluctuate voltage a little and could hear the engine/generator surge a little bit up and down. I backed the voltage down to 208 where it ran steady and let it run for about 2 hours total. I was wondering about the surging, I didn’t want to duplicate it until I checked with you guys. Am I not supposto run this set to 240? And only 208? Or do I have another problem?

I put a ammeter on the legs with voltage set to 208 with all of the elements on: (elements are not evenly distributed for all legs, so one will be lighter)
L1: 48amps
L2: 70amps
L3: 70amps
How many amps can I expect to get out of this generator per leg?

 

[bosko]

Amps draw of L1,L2 and L3 all 8 elemets running @ 208v



MEP-005a Running 75% Load after 2 hours less exhaust smoke
http://youtu.be/58RU3ZlgfJc

MEP-005a 75% Load On, then Off, Then back on
http://youtu.be/gFrosn-NWTI

 

[sewerzuk]

Today I let the generator run for about 2 hours with some load. The smoke is over all is much less, I think it must have just needed a work out to clear the pipes. I adjusted the voltage knob on the panel so I was getting 240v output. I let the generator warm and applied load little by little. Once I turned the 4[SUP]th[/SUP] pair of elements on the generator started to fluctuate voltage a little and could hear the engine/generator surge a little bit up and down. I backed the voltage down to 208 where it ran steady and let it run for about 2 hours total. I was wondering about the surging, I didn’t want to duplicate it until I checked with you guys. Am I not supposto run this set to 240? And only 208? Or do I have another problem?

I put a ammeter on the legs with voltage set to 208 with all of the elements on: (elements are not evenly distributed for all legs, so one will be lighter)
L1: 48amps
L2: 70amps
L3: 70amps
How many amps can I expect to get out of this generator per leg?

The engine surge has to do with the real load on the set; sounds like it may be having a difficult time keeping up with the load you had placed on it. A sign of wet stacking, a weak injection pump, or low compression. Most of the sets I test are capable of around 150-160% of their rating in short pulls, and 125% of their rated load indefinitely; so you really aren't pushing the limits of the set by putting 90-100% load on it. I would add a few more heaters and push it to around 110% for an hour or so...the higher EGT's help clean things out more quickly.

240v is no problem; it is within the "normal" adjustment range of the VR. A few volts higher will trip the overvoltage relay, and if it is adjusted to 240v during startup, when the field is flashed it will also trip the overvoltage relay. But, no problem running it at 240v for the purpose of load testing.

At 100% load at 208v, each leg would read about 84A. At 240v, max load would be 74A. The generator will trip on overload if any leg exceeds 130% of rated current for 8 minutes; that time decreases the more the setpoint is exceeded. If you do want to push your set to more than 100% load, you will need to balance the load a little better or the set will trip on overload before you actually get anywhere near 130%. No real problem with the unbalanced load; its just that the legs with the higher load will trip the safety before you actually are fully loaded.

 

[bosko]

I thought it would be be faster if i swapped out some of the 3,800w heaters with 5,500w heaters. So I changed 4 of them. 5,500w x 4=22,000w and 3,800w x4 = 15,200 for a total of 37,200w. That is more than 110% so I may disconnect one 3,800w heater to get to the 110% (~33,000kw).

I replaced 4 heater with 5,550w ones. And fired up the generator. I turned on all 8 heaters (37,200w), and let it it run for a few minutes. It did surge a little and puffed some inconsistent black smoke. It seemed to clear up a little. I will try to let it run a little later for an hour with 7 heaters (110%) later today if I get some free time.

Are these MEP-005 generators cold blooded? it doesn't seem to go much over 120F on the gauge. I leave the louvers almost all the way closed to try and get it to get warm. Maybe bad thermostat?

Heres some pics and video for fun.



http://youtu.be/X9uMCrTTcUY

http://youtu.be/U8w3hFXSt3Y

 

[1800 Diesel]

I like your load bank!! I need to billed something like that for my mep-005a.

I think the smoke is ok.

We're working on a similar setup for a load bank...have four 4500 watt HW elements & eight 2500 watt elements. The elements will be turned on by DP switches rated for the amperage & each element will have a red indicator light showing it's turned on. If my math is correct the elements will total up to 38 KW. For anything larger we plan to build a salt box, similar to what we used testing the shipboard generators. As for the load bank materials we've come up with everything except an enclosure for all the switches & lights. Also came across a large HW heater for salvaging the tank, but now having second thoughts about spending the time, effort & money--using the thin-shelled heater tank. Now I'm on the hunt for an old propane tank 150 gals or larger. At least it will have a thicker wall for welding in the couplings and it will also last longer as far as internal & external rusting & corrosion. It'll take several more weeks to get the project done...have many other irons in the fire...not to mention trying to make a living....will post pictures whenever it gets done....

 

[bosko]

Thanks for comments on the load bank... Im not an electrician, and probably shouldn't be "playing" with generators but I want to get familiar with electricity in general, hopefully i don't get "too" familiar with it ..

sewerzuk - my phases are too imbalanced and after reading your last post im confused with the 74amps@240v/leg. id like to rewire my elements and breaker panel so I can get the 110% load for this generator and run it for a few hours (if that is what you recommend), i can pick up some different elements if need be. How should I setup the elements and the panel?

Im using a 3ph 12slot breaker pannel, 3 slots im using for a MAIN (currently 100amp). I have a plenty of different breakers to swap in and out if i need them and several 3,800w and 5,500w 1ph 240v heaters.


I was thinking of using 3 2 pole breakers on the right side of the panel, and wire 2 5,500w elements to each breaker.

AB=5,500x2=11,000w
CA=5,500x2=11,000w
BC=5,500x2=11,000w
=33,000w = ~110%

but when I divide 11,000w by 240v i get 46Amps not the 74+ you mentioned above...??

 

[sewerzuk]

Ahh yes...we are getting into the complex world of mathematically computing 3 phase loads!
The reason you can't just measure the real load on a single phase and get an accurate current flow is that the leg is also doing some work on another phase (for example, you can't just calculate current on the AB phase, because part of the A leg is also doing some work on the CA phase, and part of the B leg is doing some work on the BC phase). That calculation (Power=volts x amps) does work if you are only loading a single phase, but it does not if you are loading more than one phase.

The correct way to calculate 3 phase power is:
Watts(real load)=Voltage(average) x Current(average) x Power factor (1 for the resistive load you are running, so don't worry about it) x Square root of 3 (about 1.7)

So, you calculated single phase current correctly; if you were to put an 11000 watt load on one leg only, it would be about 46 amps. But, since you are running 3 phase, you need to add in the current from the other phases...which brings the total to around 74 amps per phase.