Your last generator Maintenance Run

[90cummins]

I have loaded it to 13,500 with nary a grunt. Been trying to find ways to keep a load on it to prevent wet stacking. Ran it 11 hours straight then shut it down for just a few minutes to check it over and check the oil. All dry and full so I started it back up and it will probably have to run through the night.

Fortunately living in Florida as warm as it is wet-stacking shouldn't be so much of an issue.
I agree with keeping a load on it which keeps the exhaust temperatures up.
Has anyone put thermocouples on the cylinder head or exhaust to determine the temperature threshold at which wet-stacking occurs??
90cummins

 

[daugen]

Fortunately living in Florida as warm as it is wet-stacking shouldn't be so much of an issue.
I agree with keeping a load on it which keeps the exhaust temperatures up.
Has anyone put thermocouples on the cylinder head or exhaust to determine the temperature threshold at which wet-stacking occurs??
90cummins

hopefully my memory is ok but years ago I was told the big yachts idling through the no wake and manatee zones in Florida and the Intracoastal in general were
getting damaged because operating temps did not get above 150-155. The implication was get it hotter than that and problem goes away.
Now this is coolant temp; you like me want pyrometers everywhere. I would think engine design would mandate, particularly with latest emissions, that the engines get hot enough
to run cleanly no matter what. But perhaps not necessarily mandate that the engine would last a long time doing so. Most of my knowledge here is early emission control days, maybe today
things are better controlled. Would make sense they are. But for a home diesel generator, I'm not sure what Tier applies.

I'd google wet stacking and see what others think.

 

[check]

Where auto is useful is for a cottage that does not see Winter use, though many do today. It seems that many/most residential systems exercise unloaded; I was curious if Kohler was different. I like NatGas and propane for their clean-burning characteristics (don't go by oil colour re Needs Changing though....), and propane for portability. Up here, we just need to make sure propane tank surface area is adequate (low temperatures), and any pro-installation would address that. Rgds, D.

Our cottage is winterized and we do use it quite a bit in the winter. That is why we got an automatic standby generator in the first place. (That and the hot tub!)

 

[3930dave]

Our cottage is winterized and we do use it quite a bit in the winter. That is why we got an automatic standby generator in the first place. (That and the hot tub!)

Getting through a power-outage without the hot-tub ? Now that's struggling through a Canuck Winter ! :laughing:

All joking aside, if you get snowed in up there (roads closed), you may be there a while....

Rgds, D.

 

[3930dave]

Fortunately living in Florida as warm as it is wet-stacking shouldn't be so much of an issue.
I agree with keeping a load on it which keeps the exhaust temperatures up.
Has anyone put thermocouples on the cylinder head or exhaust to determine the temperature threshold at which wet-stacking occurs??
90cummins

That's an excellent point 90......

I've never built one to run that way, but I'm used to people using Thermocouples on diesel trucks for performance builds - the worry being high EGTs in those builds...... IIRC 1200F or thereabouts being the ceiling.

I've poked around a bit on the 'net just now, looking for minimum diesel EGT info, but didn't come up with much...... I suspect that info is manufacturer specific, and perhaps not that commonly shared ?

I did find a few good related diesel articles, and am posting 2 here. One does a good job of describing wet-stacking, and the CAT one cites 30% of capacity as the target for minimum operating load. CAT paper goes on to comment that esp. in cases where diesels are too lightly loaded then exercising them with significant loads is a valuable maintenance process....

This diesel low-EGT temperature question is definitely worth clarifying. W/O installing a thermocouple I'd be tempted to baseline a diesel generator I had with an IR gun - run the unit at something like 50/75/100% loads at typical ambient temps, and measure a defined spot at the exhaust manifold output - once the reading settled for a given load, then that would be my (seat of the pants....) baseline # for that generator. Then I'd compare the same reference spot with cold ambient temperatures and 30% and say 10% loads, and see how much EGTs dropped.

But... that still leaves the question "How low is too low for diesel EGT ?".

At this point I can't distinguish between that low-limit diesel EGT # being poorly understood versus just being closely-held proprietary information. Based only on a quick read tonight, the rule of thumb seems to be "Watch for these symptoms (slobber, oil dilution....); if you see them, then you have a problem.....". Clearly, better data would be useful.

View attachment is_09_wet_stacking.pdf

View attachment CAT_re_Underloading_generators.pdf

Rgds, D.

 

[check]

Getting through a power-outage without the hot-tub ? Now that's struggling through a Canuck Winter ! :laughing: All joking aside, if you get snowed in up there (roads closed), you may be there a while.... Rgds, D.

Ha! We don't DO snowed in!

 

[PILOON]

I only have a 6000 watt portable.
I keep a battery maintainer hooked up at all times as I hate hand cranking.
To exercise my genset I connect an old 2000 watt baseboard heater as my load.
About 10 mins run time gets it nice and warm, enough to boil away and internal condensation.
Only using high test gas is another must as U don't want any alcohol laced gas that gums things up. Also alcohol attracts water.
So far this basic system (connected via a transfer panel) has served me well.

 

[3930dave]

I only have a 6000 watt portable.
I keep a battery maintainer hooked up at all times as I hate hand cranking.
To exercise my genset I connect an old 2000 watt baseboard heater as my load.
About 10 mins run time gets it nice and warm, enough to boil away and internal condensation.
Only using high test gas is another must as U don't want any alcohol laced gas that gums things up. Also alcohol attracts water.
So far this basic system (connected via a transfer panel) has served me well.

6kw will handle most household emergency loads well, and 2kw loading sounds appropriate for a gas-engined gen.

I too am an Efree fan. Unfortunately, that is not always readily available, depending where one lives....

Rgds, D.

 

[3Ts]

Those of you who load your generators, how do you do that? Just turn on lights and appliances when on the generator, or do you have a load bank that you use?

I was thinking that 4 water heater elements of 4500 watts would be a good load for a whole house generator. (In a water tank big enough to keep from boiling the water). I can't think of any other method at the moment that would provide a heavy load.

 

[check]

What does it have to be really heavy? Why not just the dryer or maybe the oven in the stove?