Buying Advice Aurora Silent Diesel Generator

[TractorBob1529]

Rayko thanks for the input on your genny. Got some sound tips for breaking in a genny. If im going to buy a new genny im leaning toward a diesel one. And welcome to the TBN.

crazyall thanks for your input on the well distance. I think im going to get somebody to recur the whole two meter thing and have one for all my electrical needs.

 

[ModMech]

From what I can ascertain, HF and NT edits all reviews before posting.......

HF offers a nice Detroit Diesel (3-71) genset for I think, 4 grand.

Correction, 5 grand ($4999) and you'd better at least OFFER some of it's power to your neighbors or they will be planning sabotage after the first 5 minutes it is running!

20 KW Generator

Notice they are "reconditioned", DDA has not built a "new" 2-stroke engine in many years, almost 10 I think.

 

[jenkinsph]

Correction, 5 grand ($4999) and you'd better at least OFFER some of it's power to your neighbors or they will be planning sabotage after the first 5 minutes it is running!

20 KW Generator

Notice they are "reconditioned", DDA has not built a "new" 2-stroke engine in many years, almost 10 I think.

Years ago I had two of these 3 71 20kw gensets on a tug, swapped them out every 24 hrs, one of them was always running 24hrs/365 days a year. Fuel wasn't an issue as it is today. Nothing quiet about them but these were much preferred over the 2 71 20kw 1800 rpm model much more noise and shorter life between rebuilds.

 

[TimberXX]

These Aurora's seem like nice units, that are at an attractive pricepoint.

The liquid cooled ones are rated at 10,000 hours. Any idea how many hours you would get out of an air cooled? 5,000 hours maybe?

 

[ayelvington]

My 2006 Aurora 6500 generator let me down after running for 5 hours (60 hours total). It was VERY hot, and some of the rubber inside the case was smoking. No, the oil pressure lamp was NOT lighted.

I called Aurora and talked with Ron. He pointed out that a malfunctioning fuel pump solenoid will lean the mix, make the generator run hot, and eventually cause the generator to shut-down.

Aurora has always answered the phone and had the parts, so I'm very grateful for that! I'm going to suit up and take a look at the fuel pump now to see if I can get it running today.

Update 7/27/2012

The generator was installed on a pedestal for easy of changing the oil and accessing the front panel. I just put in a chain hoist to make it easier to remove and replace for servicing.

Ron has been great with phone support, and I'll be doing an overdue groom on the engine this weekend, with the hope of finding what went wrong. I've been running it without enough load for many years, so I'm inclined to think that the problem is related to that. A load bank may be in the future.

 

[ayelvington]

Air cooled units will likely get a quarter (or less) of the service life of a liquid cooled unit. Generators are expensive no matter how you look at them. I think our Amish neighbors must consider us crazy!

These Aurora's seem like nice units, that are at an attractive pricepoint.

The liquid cooled ones are rated at 10,000 hours. Any idea how many hours you would get out of an air cooled? 5,000 hours maybe?

 

[BobRip]

Air cooled units will likely get a quarter (or less) of the service life of a liquid cooled unit. Generators are expensive no matter how you look at them. I think our Amish neighbors must consider us crazy!

Is this generator going to be used for continuous service or just emergency or occasional use? If just the later even 500 hours will last you many years or even decades.

 

[ayelvington]

Is this generator going to be used for continuous service or just emergency or occasional use? If just the later even 500 hours will last you many years or even decades.

I agree! Our generator really only logs about 12 hours a year. If you're going for continuous service, be sure to match to your load or you'll have troubles with carbon build up. I just ordered a 240V space heater to act as a test load bank and supplemental load since our generator doesn't really get loaded until everything is on (including the water pump). TPI Corp. electric space heater model H474TMC 4000 watt heavy duty 240 volt | eBay is an affordable load bank with 2kw/4kw settings.

 

[ayelvington]

This is an update to my post from yesterday.

I pulled the injector and found it hopelessly fouled with carbon. This is a 6.5kw generator running with less than 1kw of load unless the water pump turns on. The years of running it practically unloaded were hard on it, and it's cheaper to replace the injector than to waste the time trying to clean it right now.

I also ordered a 2kw/4kw 240V space heater to use as a load bank for testing or to bring up the load when demand is low. TPI Corp. electric space heater model H474TMC 4000 watt heavy duty 240 volt | eBay This is very affordable, and I'll just dump the heat outside when we don't need it inside. (The generator already does a great job of heating the garage...)

I also ordered a pair of current transformers (CT) and meters to put in my auxilliary power panel so that I can look at the load at a glance. Rectangle Analog AMP Meter AC 50A + Current Transformer | eBay Let's hear it for Coast Guard training on power systems! I expect that I'll put the 2kw load on frequently to keep the generator above 25% of capacity. I'll need to cycle the water pump to see how much head room will be left over for that.

Bottom line: No complaints what so ever about Aurora Generators!

Here's a link to a very short video of what you see when your injector is clogged:

Clogged generator injector operation while cranking - YouTube

And here's what the injector SHOULD look like when your cranking the engine:

Diesel Generator - Fuel Injector - YouTube

Here's a very nice video on how the injector works. Aurora Generators use hole-type injectors, and you get an idea of why you don't want your skin near the injector when it's in operation.

How a diesel fuel injector works

 

[ayelvington]

Placed my order for a new injector and an oil filter gasket today, and had a shipment tracking number before the day was over. Very glad that I bought from Aurora and not some Ebay.

 

[ayelvington]

Wet stacking: I had heard of this before, but I never dealt with it until my generator stopped working because of a carbon-clogged injector. If you're running a diesel generator for prime or back-up power, it's something you need to be aware of and mitigate by ensuring you have enough of a load on the engine.

Here is a great primer to help you along: http://www.kraftpower.com/pdfs/KPC_IS_17_Wet_Stacking.pdf

Space heaters make very affordable load banks for small generators, and the one that I referenced before ensures a balanced and purely resistive load. I remember watching a portable generator grunt at a cabin when someone plugged in a toaster!

Another trap folks get into is testing a battery-powered transfer switch while the batter charger is connected. (I've seen this go very badly under emergency conditions.) Make sure that the transfer equipment works properly with only the battery running it. Boiled batteries can appear charged to a charger, and do nothing for you when the lights go out.

Anyway, no matter whose generator you buy, be sure to exercise it periodically under load to make sure it works, and to blow the carbon out.

 

[Skyco]

I called Aurora and talked with Ron. He pointed out that a malfunctioning fuel pump solenoid will lean the mix, make the generator run hot, and eventually cause the generator to shut-down.

I hope that isn't what he told you. A diesel always runs "lean" unless it is overfueled (notice I did not say -rich-) it cannot be run too lean and there is no "mix"..

 

[BobRip]

I agree! Our generator really only logs about 12 hours a year. If you're going for continuous service, be sure to match to your load or you'll have troubles with carbon build up. I just ordered a 240V space heater to act as a test load bank and supplemental load since our generator doesn't really get loaded until everything is on (including the water pump). TPI Corp. electric space heater model H474TMC 4000 watt heavy duty 240 volt | eBay is an affordable load bank with 2kw/4kw settings.

Do you have to keep it loaded most of the time or just occasionally?

 

[ayelvington]

I hope that isn't what he told you. A diesel always runs "lean" unless it is overfueled (notice I did not say -rich-) it cannot be run too lean and there is no "mix"..

Actually, it can when it's malfunctioning! (I agree with you for normal operation, but this was not normal.) The generator was running with virtually no load, so it was in the process of wet-stacking since much of the fuel was not burning (too rich). As the jets clogged (there are 4), the mix leaned, but the engine did not slow since there was virtually no load. As the air/fuel mix went to lean (abnormal operation), the combustion temperature went up which explains why the head got so hot. Eventually the last jet clogged and the engine stopped running.

None of this could/would have happened if the engine had been properly loaded so that the temperature would have been where it belonged, and changes in the quantity and time of the fuel injection would have changed the available power/torque/rpm.

 

[ayelvington]

Do you have to keep it loaded most of the time or just occasionally?

It's really not a good idea to run it unloaded because of the gradual wet stacking. Mind you, my machine had over 60 hours on it before it grunted, but it was not good for it. I strongly recommend you read the document that I referenced earlier, and I'm going to exercise mine at 80% load (4 kW) from now on. I have current meters on the way so that I can monitor the load when the house is being backed up, and make sure there's at least a 50% load on it to prevent wet stacking.

The reference document that I cited earlier gives the NFPA code requirements for exercising an emergency generator. Good reading!

This is the first time that I've dealt with a generator that was too big for the load! I guess it's one way to learn

 

[Skyco]

I hope that isn't what he told you. A diesel always runs "lean" unless it is overfueled (notice I did not say -rich-) it cannot be run too lean and there is no "mix"..

Actually, it can when it's malfunctioning! (I agree with you for normal operation, but this was not normal.) The generator was running with virtually no load, so it was in the process of wet-stacking since much of the fuel was not burning (too rich). As the jets clogged (there are 4), the mix leaned, but the engine did not slow since there was virtually no load. As the air/fuel mix went to lean (abnormal operation), the combustion temperature went up which explains why the head got so hot. Eventually the last jet clogged and the engine stopped running.

None of this could/would have happened if the engine had been properly loaded so that the temperature would have been where it belonged, and changes in the quantity and time of the fuel injection would have changed the available power/torque/rpm.

You hit on the likely real problem in your last sentence. Again a diesel, especially a single cylinder one, cannot run too lean.

What likely happened is as the injector clogged the timing was off since injector pop off pressure changed or the injector was dribbling (in effect uncontrolled timing) and THAT is what made your diesel overheat.
If timing stayed the same as the injector clogged power would go down, but it will not and cannot run "too lean".

 

[DarkBlack]

It's really not a good idea to run it unloaded because of the gradual wet stacking. Mind you, my machine had over 60 hours on it before it grunted, but it was not good for it. I strongly recommend you read the document that I referenced earlier, and I'm going to exercise mine at 80% load (4 kW) from now on. I have current meters on the way so that I can monitor the load when the house is being backed up, and make sure there's at least a 50% load on it to prevent wet stacking.

The reference document that I cited earlier gives the NFPA code requirements for exercising an emergency generator. Good reading!

This is the first time that I've dealt with a generator that was too big for the load! I guess it's one way to learn

That sounds like a double PITA. You have to worry about a minimum 50% load, so there goes any fuel savings, and then if you have it loaded with dummy loads, then you risk not having enough headroom for some real loads that may kick on. Also 50 hours seems like an awfully short time to fail.
I think I'll stick with my petrol backup.

 

[daybreak1998]

Howdy,
Any generator (gas, diesel, propane, natural gas) should have a load put on it. This is not just for the engine, but for the magnetic needs of the generator (alternator) head. The same thing can be said about someone not using a generator for a long time and then runs it, only to find it then does not produce power. You would then need to do a field flash, which is like jump starting the windings and making a magnetic field to then produce energy.

Engine have rings, the pistons might go up and down, but the rings need to seat. Like anything, non-use is hard on a engine. Even a old old car, the engines still needs to run and brought up to proper operating temperture. That is why the standby generators out there have the exercise cycles which obvoisly run longer than 5 minutes.
60 hours on a generator is longer then you think.

 

[DarkBlack]

Howdy,
Any generator (gas, diesel, propane, natural gas) should have a load put on it. This is not just for the engine, but for the magnetic needs of the generator (alternator) head. The same thing can be said about someone not using a generator for a long time and then runs it, only to find it then does not produce power. You would then need to do a field flash, which is like jump starting the windings and making a magnetic field to then produce energy.

Engine have rings, the pistons might go up and down, but the rings need to seat. Like anything, non-use is hard on a engine. Even a old old car, the engines still needs to run and brought up to proper operating temperture. That is why the standby generators out there have the exercise cycles which obvoisly run longer than 5 minutes.
60 hours on a generator is longer then you think.

I disagree. Gas generators do not "stack". It's totally not the same issue.

 

[BobRip]

I disagree. Gas generators do not "stack". It's totally not the same issue.

Stacking is not a problem, but non use is. That was the point he is making.