Single 4160v generator vs 8 low voltage?

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Todd0x1 said:
Natural gas doesn't seem like the most resilient fuel supply for an emergency backup generator, I'd use diesel.
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I use to lean more heavily towards diesel for that reason. But with diesel you have problems with long term fuel storage. Water gets in the storage tanks due to condensation or some other cause. Anaerobic bacteria lives in the interface and feeds off the fuel. Makes a big mess in the tank and is commonly referred to as "algae". The algae gets in the fuel system and plugs up the filters when the generator runs under load and it kicks out due to low frequency. I find that most don't do the proper maintenance to prevent this. There are companies who specialize in doing this for large storage tanks. It's called "fuel polishing" They add a biocide to the fuel and run it through a filtering process to remove the dead bacteria.

For myself, I'd still probably use diesel. But for a customer I'd lean more towards propane. Propane in it's tank lasts forever
 
Joethemechanic said:
I use to lean more heavily towards diesel for that reason. But with diesel you have problems with long term fuel storage. Water gets in the storage tanks due to condensation or some other cause. Anaerobic bacteria lives in the interface and feeds off the fuel. Makes a big mess in the tank and is commonly referred to as "algae". The algae gets in the fuel system and plugs up the filters when the generator runs under load and it kicks out due to low frequency. I find that most don't do the proper maintenance to prevent this. There are companies who specialize in doing this for large storage tanks. It's called "fuel polishing" They add a biocide to the fuel and run it through a filtering process to remove the dead bacteria.

For myself, I'd still probably use diesel. But for a customer I'd lean more towards propane. Propane in it's tank lasts forever
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Not that big of a deal, racor makes a fuel polisher you can install in the generator. https://ph.parker.com/us/en/product/pump-and-filter-fuel-polishing-system/p510mam
 
jroscow said:
Just outside - half acre and let’s do it lol
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hmm..... I do have two brand new (~2 hours) skid mounted open frame 65 kva units sitting here, isuzu 4JJ1 engine and oversize meccalte alternator. 120/208 or 277/480 or 120/240 1ph.
 
Todd0x1 said:
Not that big of a deal, racor makes a fuel polisher you can install in the generator. https://ph.parker.com/us/en/product/pump-and-filter-fuel-polishing-system/p510mam
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You would probably do it right, and so would I. Customers on the other hand never maintain those systems right. I did some generator inspections for one of the largest cities in the US. Wrote them a report on every generator site with all the maintenance concerns and my recommendations. One site of super critical infrastructure had two 600KW diesel generators. One large storage tank with pumps to fill each generator's day tank. Storage tank was fine, but both day tanks had like 3 inches of water and were all slopped up with algae. so I tell them they need to treat the fuel with Kathon fp 1.5 biocide. and they have to get someone in to remove the water and fuel polish the day tanks.

Six months later I'm back at that site and notice the separators have water in them, and are all slopped up with Algae. I ask the rep from the city, Didn't you treat the fuel and have the fuel polishing done" He says yeah we did. Now I'm trying to figure out how so much water got in the day tanks in 6 months. Turns out they had the fuel polishing done on the bulk storage tank and never did anything about the mess in the day tanks
 
Joethemechanic said:
You would probably do it right, and so would I. Customers on the other hand never maintain those systems right. I did some generator inspections for one of the largest cities in the US. Wrote them a report on every generator site with all the maintenance concerns and my recommendations. One site of super critical infrastructure had two 600KW diesel generators. One large storage tank with pumps to fill each generator's day tank. Storage tank was fine, but both day tanks had like 3 inches of water and were all slopped up with algae. so I tell them they need to treat the fuel with Kathon fp 1.5 biocide. and they have to get someone in to remove the water and fuel polish the day tanks.

Six months later I'm back at that site and notice the separators have water in them, and are all slopped up with Algae. I ask the rep from the city, Didn't you treat the fuel and have the fuel polishing done" He says yeah we did. Now I'm trying to figure out how so much water got in the day tanks in 6 months. Turns out they had the fuel polishing done on the bulk storage tank and never did anything about the mess in the day tanks
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wow.
 
Todd0x1 said:
wow.
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They were also impossible to convince that just because they started up for an exercise cycle and ran up to 1800rpm without a load and made voltage was proof that they could be relied on even though the whole fuel system was all slopped up. No way could you explain to them that 1800 loaded required much more fuel flow than 1800 idle.

But OMG if the oil and lube filters change they had us do every 6 months was a week late they would have fits. Damn things ran like 15 hours during the 6 months.

Most of the communications tower sites used Spectrum gens with 460 Fords on natural gas. At first I thought that was stupid. Who is to say the Natural Gas distribution is going to function if something really bad happened? After a few years I came to the conclusion that the NG units were more likely to run under load than the diesels
 
I recall reading that in most populated areas, the natural gas utility is the most reliable in terms of service delivery followed by the large water systems. Electric was behind those. Sure, they all go out at one time or another, but electric seems to do it more.

In terms of generators, what's the reliability of fuel delivery for the specific location? If you have natural gas, it's probably going to "just work".
 
zbang said:
I recall reading that in most populated areas, the natural gas utility is the most reliable in terms of service delivery followed by the large water systems. Electric was behind those. Sure, they all go out at one time or another, but electric seems to do it more.

In terms of generators, what's the reliability of fuel delivery for the specific location? If you have natural gas, it's probably going to "just work".
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Leaning heavily towards 8 LV natural gas generators with an ATS

Thanks again for all the input!
 
Hi Jroscow,

IT sounds like you are leaning the right direction. I am an applications engineer with a Generac distributor. With 25 years of engineering experience in emergency power I can say that the thought process and comments on this thread are pretty good.
  1. Natural gas is very reliable
  2. Diesel is hard to maintain
  3. Copper is expensive to install
 
PaulMmn said:
Do buried electrical systems reduce outages to the same level as water and gas?
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Yeah but underground is crazy expensive and hard to do for any kind of serious distance. I think the average cost needs to be increased tenfold, and there are problems with low leading power factor due the close proximity of the conductors because you have just created a big capacitor.

Then there is also the potential problem of ferroresonance because the line is now a capacitor, and you are hooking it to a transformer that is an inductor. So you just have created a tank circuit
 
jroscow said:
Looking at 400kw natural gas after chatting with generac about what would be powered
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Ok, think this through a little. Who buys the fuel and pays for routine testing, maintenance, etc.? If two residents turns on their hot tubs, 4 car chargers, sets their ACs to 62 and runs their oven all at the same time, overloading the generator when the other 6 residents are being reasonable, how is that handled?

Having separate generators is all around cleaner.
 
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