803a load testing questions

[m32825]

Got a coil top stove and have been using it to load my system. First time it has had anything other than convenience outlet exercise.

It was originally dropping out around 32A@240V. The AC interrupter light would go out and the engine would be back to running at no-load speed.

After cleaning and exercising S8 it sustained 48A@240V, everything the oven could give it, for half an hour (ran out of daylight).

Tracked down the oven's lower element wiring and hard-wired it "on" so I could run all both stove elements at the same time for more load. Was able to get 60A@240V, reading a little over 115% load. This ran for a little while (maybe a minute?), then the engine shut down and the "over voltage" light was on. Is this normal behavior for an overload situation? What was causing the interrupter drop out I saw initially?

-- Carl

 

[csheath]

Are you reading/adjusting the voltage with the unit gauge or a known good voltmeter at the output legs?

 

[m32825]

I'm looking at a Kill A Watt plugged into the convenience outlet, and the control panel voltmeter agrees, but I didn't check the lugs with a multimeter, will add that to the "next time" list.

-- Carl

 

[csheath]

Connect a known good volt meter between L1 and L3 to see what the voltage really is. These gauges are known to be inaccurate at times.

 

[Guyfang]

Always use the lugs, when possible. Over voltage light, or Over load? The K-5 is respond able for both functions. So you could get the over volt light instead of the over load.

 

[csheath]

I would adjust to 240 between the lugs and then check from each line under load to make sure they both stay at 120. When I first got mine it was dropping voltage on L1 under load. I had to clean and recrimp connectors and exercise the switches and finally got it to maintain a steady voltage reading on both legs. Hertz will drop a little under load and there isn't much you can do about it but voltage should remain steady. There is an adjustment for hertz droop but it didn't have much effect on mine. I set mine at 61 with no load and settle for 59 under full load.

 

[m32825]

I did a little more testing, it was a volt or two high at the lugs. Voltage on both lugs is stable under load.

Tried to repeat the overload test result but getting different behavior now. The unit hangs in there with the load for a while, then begins to lose rpms and shuts down.

I could have sworn it was over voltage I saw before, but then I looked at the panel again and now I'm not sure. Need to get in the habit of taking pictures as I go...

-- Carl

 

[jamawieb]

Sure it didn't over heat? Will it restart right after it shuts down? If not, then it got to hot and it has to cool.

 

[Daybreak]

Howdy,
A few pointers.
A good full tank of diesel. Some additive if you have not had the unit long and do not know its history. A good hard loaded run at 80% or better for 4 hours will help clean out the cobwebs.

That way you know you can rely on it when you need it.

Acquired a Military surplus load bank

 

[m32825]

Sure it didn't over heat? Will it restart right after it shuts down? If not, then it got to hot and it has to cool.

Yep, starts right back up. It gets a low oil pressure light but I think that's because the engine is being dragged down to a stop. I've checked the oil pressure with an analog guage and it's fine.

Reading the technical manual, it looks like when you get overload or over voltage lights that the interrupter opens up and the engine keeps running, am I understanding that right? If so, I'm wondering if maybe my governor has an issue. I notice a bit of squealing when the unit starts that goes away after a few seconds, haven't been able to figure out where it is coming from, maybe that's related somehow?

-- Carl

 

[m32825]

Howdy,
A few pointers.
A good full tank of diesel. Some additive if you have not had the unit long and do not know its history. A good hard loaded run at 80% or better for 4 hours will help clean out the cobwebs.

Thanks, good suggestions. I'm working towards giving it a few hour continuous run.

-- Carl

 

[Guyfang]

Like Daybreak said, give it 4 hours at 80%, to work the engine up. Give it a chance to get good and warm. Burn out some carbon. Then you can bump it up. Can you run 60 clicks without working up to it? Bet not. But after working your way up to it, you should be able to do it. A gen set is no differant.

 

[zarathustra]

Does your unit have a Facet 40193 fuel pump?

 

[m32825]

Does your unit have a Facet 40193 fuel pump?

Hmm, good question. Will check it next time I pull the tarp. Does that one have known issues?

-- Carl

 

[zarathustra]

I have several NOS Facet pumps (40193) and about half are DOA. You can identify them from across the room... they're square-ish pumps and the Airtex replacements are like canisters.

I believe that a poorly functioning Facet pump can pump fuel fine during low demand, but can have have trouble at peak demand situations. The Facet pump is a high pressure, low volume pump...

If your generator is working fine, but as you increase demand to a point it simply cuts off -- like it is running out of fuel ---- I think it could be the pump.

One way to test that is when it starts to cut out at high load reduce the load by about half. If it quits coasting down and begins running properly again it's telling you that it is running out of fuel at peak demand (load). Given the fact that the Military "deep-sixed" the Facet pump for Airtex I believe that the Facet 40193 had performance issues.

Could be a governor problem, but the symptom I'd expect there is for the engine to begin bogging down rather than cutting off.

If that is your problem then you might be able to adapt the generator's AUX pump (40194) to replace it. The primary physical difference between 40194 and 40193 is the size of the fittings. The primary performance difference is that 40193 is high pressure / low volume whilst the 40194 is low pressure / high volume.

I haven't tried that, but if fuel delivery is the problem then that would improve the delivery issue.

If you have an Airtex pump, then I'd still suspect some sort of fuel delivery issue if your problem matches the above described symptoms.

 

[Guyfang]

This is the prime reason CECOM demanded a new pump. The Airtex model.

 

[zarathustra]

Now, finding the elusive Airtex E1074 pump is another matter. Frankly I don't think that Airtex ever made an E1074 model fuel pump.

Their web site does not show one, and no where can I find the specs on one. I called Airtex about an E1074 pump a while back and the techs there were very quick to tell me that an 8135 pump would work just fine.

So, since if one was prone to be a little cynical, he might wonder whether Airtex simply printed a label marked E1074, pasted it on the 'ol stand by 8135 pump and sold it to the Military. That beats having to spend money to develop a new pump for the Military, and it is a proven pump, and it could be done fast.

But a re-furb of a 40194 would definitely supply more fuel (higher GPH rating), just at a lower pressure. If I remember correctly the 40194 specs were similar to the 8135. That makes me more confident that a 40194 adaptation to to be the main fuel pump might just work fine.

40194 pumps are not hard to find. Look on the ebay UK site as well as the US site

 

[Guyfang]

2910- 01-565-9234 is the NSN for the Airtex pump. In my browser, it came up with multible listings. Org. cost S35.00

71425

AIRTEX PRODUCTS

DIV OF UIS INC

407 W MAIN ST

FAIRFIELD

IL

62837-1622

PHONE: 618-842-2111

View attachment MainFuelPmp.pdf

 

[Daybreak]

Howdy,
The 800 series TQG has 2 different fuel pumps. The older style is a square Facet electric fuel pump. The newer style is a round Airtex E1074 fuel pump. This is the primary pump location item. A lot of the units already have these mounted, or have been replaced with the round Airtex fuel pump.

MEP-802A fuel pump (primary)
MEP-812A fuel pump (primary)
MEP-803A fuel pump (primary)
MEP-813A fuel pump (primary)

The picture below shows the components.
NSN 2910-01-565-9234 E 1074 PUMP,FUEL,ELECTRICAL 24V (pump only)
NSN 2910-01-553-6571 FILTER ELEMENT,FLUID (small barrel filter only)
NSN 2910-01-491-1340 PARTS KIT,METERING AND DISTRIBUTING FUEL PUMP (full replacement kit = pump, filter, and steel line piping*(approx. 4 inch piece)

I also talked with Airtex about the unit. They are hooked with Southern Automotive. I called them, they want nothing to do with it, unless you are buying 100 units.

The NSN 2910-01-491-1340 is the full Facet replacement kit. It has the pump and the little 4 inch hard line connector.

I wanted a full kit as a spare, but not finding it. At one time some were sold here ( old listing )

It is also one of the Tier reset items

 

[Guyfang]

Got to keep an eye out for it. Every once in a while, one comes up for sale. Since I don't need one, I don't look often. As a mater of fact, I have seen several here in germany.