Generator Size Vs. Service Amperage

[Joethemechanic]

Nonsense, I just finished load banking a 3 year old 150 kw generator with a John Deere 6 cylinder high pressure common rail engine and one of the exhaust manifold ports had leaked wet stacking gunk all down the side of the block. When we put the screws to it, the customer came running to see what was on fire. Cleaned right up after a while.

Everything I've seen wet stack in recent years has had something wrong with it. Low operating temp, bad injector, low compression, etc. To wet stack bad enough for you to see fuel leaking out of the manifold is really bad. Something other than light loading has to be wrong. That John Deere being as new as it is has to be at least a Tier 3 emissions engine even if it's a standby unit. It can't be spewing out tons of unburned hydrocarbons and make those standards

 

[Birken Vogt]

Well I'm a diesel mechanic first and I can tell you this one has none of those things wrong with it except it runs no load for hours/days on end since it belongs to a water department and is automatic standby, I'm sure you know the load profile, runs a pump once in a while but the rest of the time just keeps the power on.

Yes it's Tier 3, same engine model number and config as any number of units we service all around the area.

Nevertheless everything needs to be load banked annually for any number of reasons, if you ain't testing you're guessing.

 

[garbo]

This plant is for a small town that compared to some. Township of only about 2500 people. Hence the smaller motors and such. The generator fuel source has been decided upon as Natural Gas for those that wanted to know. It was asked of me to size the generator to whole plant backup with a 40% upsize as well.

Good luck with natural gas generators .Large hospital that I retired from had 4 760 KW PIG CAT gen sets that only ran at 1200 RPM and a maybe a 700 KW natural gas gen set for a new high rise office. Even after they spent a ton of money overhauling the 760 KW units along with all new controls we were unable to load bank the pigs at 700 KW especially during warm weather. They also required not four huge 12 volt batteries for two 24 volts starters but six huge batteries for three starters. They needed the third starter to get at least one of them started & supplying emergency power to ATS'S within ten seconds. We had trouble with the 700 KW natural gas gen set during every monthly ATS testing. Would provide too high of a voltage preventing transferring power to ATS'S. Good point the easy overtime Sunday morning test took three times longer while electrical contractor, ASCO ATS tech & CAT techs scratched their heads for a few hours. 25 year old diesel 2000 KW gen sets ,could be load bank at full power ( 2,000 KW ). The four natural gas gen sets took at least halve a hour every week to pull off the 144 battery caps and plunk down a water filling auto fill bottle with RO/ distilled water.

 

[Joethemechanic]

Good luck with natural gas generators .Large hospital that I retired from had 4 760 KW PIG CAT gen sets that only ran at 1200 RPM and a maybe a 700 KW natural gas gen set for a new high rise office. Even after they spent a ton of money overhauling the 760 KW units along with all new controls we were unable to load bank the pigs at 700 KW especially during warm weather. They also required not four huge 12 volt batteries for two 24 volts starters but six huge batteries for three starters. They needed the third starter to get at least one of them started & supplying emergency power to ATS'S within ten seconds. We had trouble with the 700 KW natural gas gen set during every monthly ATS testing. Would provide too high of a voltage preventing transferring power to ATS'S. Good point the easy overtime Sunday morning test took three times longer while electrical contractor, ASCO ATS tech & CAT techs scratched their heads for a few hours. 25 year old diesel 2000 KW gen sets ,could be load bank at full power ( 2,000 KW ). The four natural gas gen sets took at least halve a hour every week to pull off the 144 battery caps and plunk down a water filling auto fill bottle with RO/ distilled water.

3500 series Cat?

 

[tortuga]

Good luck with natural gas generators....

Yeah and I am surprised a wast water treatment operation critical / backup operations plan would rely on a off site utility to remain operational during a blackout vs on site storage of some sort like diesel.

 

[Hv&Lv]

Call the power company and ask for the peak demand. Simplest way.

 

[Joethemechanic]

Yeah and I am surprised a wast water treatment operation critical / backup operations plan would rely on a off site utility to remain operational during a blackout vs on site storage of some sort like diesel.

They are avoiding having bulk storage tanks on site. If the generators run or not is not their concern. All they care about is if they have met their legal obligation to have backup power. BTW from working on municipal installations, they never maintain their bulk storage tanks either. They are always slopped up with water and "algae". They think that because the sets fire up and run for a short time off of the day tanks that everything is just peachy keen

 

[Birken Vogt]

They are avoiding having bulk storage tanks on site. If the generators run or not is not their concern. All they care about is if they have met their legal obligation to have backup power. BTW from working on municipal installations, they never maintain their bulk storage tanks either. They are always slopped up with water and "algae". They think that because the sets fire up and run for a short time off of the day tanks that everything is just peachy keen

When I was reading the first part of your paragraph the same words were on the tip of my fingers.

I've got one diesel Cummins 855 right now that has been unloaded/light loaded for all its life, as soon as I put a couple hundred kw to it, falls on its face. Fuel hoses are disintegrating and tank is full of scum.

They also have a NG unit on the property, runs OK but can't reach full load, gas pressure falls away. Now I have to go troubleshoot some oxygen sensor fault that came later.

They all have problems and we stay in business.

 

[Joethemechanic]

Fuel hoses are disintegrating and tank is full of scum.

I couldn't count how many suction line restrictions I've found over the years. Hoses disintegrating, rubber bands, fuel cap rubber, cigarette butts.....

And by the time they get to me, they almost always have a new injection pump, nozzles, and turbo. It's like they go for the most expensive stuff and fire the parts cannon.

As far as the gen sets go, I find slopped up tanks in some seriously critical infrastructure. Police and fire stations, 911 call centers, communications sites, city hall and I'm not talking out in Podunkville, I'm talking about large American cities.

You can explain to them that they need someone to come in and do fuel polishing, but it's never in the budget. But what is in the budget is doing an oil change every 6 months even though the hour meter has only racked up 12 hours and completing a meaningless checklist that looks like some numbnuts that works at Jiffylube made it up

 

[garbo]

I couldn't count how many suction line restrictions I've found over the years. Hoses disintegrating, rubber bands, fuel cap rubber, cigarette butts.....

And by the time they get to me, they almost always have a new injection pump, nozzles, and turbo. It's like they go for the most expensive stuff and fire the parts cannon.

As far as the gen sets go, I find slopped up tanks in some seriously critical infrastructure. Police and fire stations, 911 call centers, communications sites, city hall and I'm not talking out in Podunkville, I'm talking about large American cities.

You can explain to them that they need someone to come in and do fuel polishing, but it's never in the budget. But what is in the budget is doing an oil change every 6 months even though the hour meter has only racked up 12 hours and completing a meaningless checklist that looks like some numbnuts that works at Jiffylube made it up

The large hospital that I retired from had a company come and run hoses to the two.large underground diesel. Finally found out that its called " Polishing ". One place that I worked at only had a single service so had a diesel engine run the fire pump. We had to add maybe a quart of fuel conditioner into the fuel tank every time we test ran it.At the Hospital we took oil & coolant samples every month and even though none of the 19 large generators most likely never had more then 100 running hours a year they had the oil & filters changed every year. Not sure if it was a JACHO rule but all the batteries for the hospital generators were replaced every two years. We checked battery water level every week. For years we had the sealed batteries like cars have had since the 1970's but CAT dealer said they had some blow up and only started selling batteries with filler caps. Our generator batteries almost always needed some water because my thinking is they used 24 volt from batteries to operate gen set controls.

 

[Joethemechanic]

The large hospital that I retired from had a company come and run hoses to the two.large underground diesel. Finally found out that its called " Polishing ". One place that I worked at only had a single service so had a diesel engine run the fire pump. We had to add maybe a quart of fuel conditioner into the fuel tank every time we test ran it.At the Hospital we took oil & coolant samples every month and even though none of the 19 large generators most likely never had more then 100 running hours a year they had the oil & filters changed every year. Not sure if it was a JACHO rule but all the batteries for the hospital generators were replaced every two years. We checked battery water level every week. For years we had the sealed batteries like cars have had since the 1970's but CAT dealer said they had some blow up and only started selling batteries with filler caps. Our generator batteries almost always needed some water because my thinking is they used 24 volt from batteries to operate gen set controls.

All the ones I took care of on critical infrastructure had heated battery blankets, battery tenders, and block (coolant) heaters. A couple had magnetic heaters that stuck on the bottom of the oil pan, but that was kinda overkill. Greater Philadelphia area is considered "subtropical climate", not to mention they were all in heated buildings or enclosures. I had to laugh because the one installation had two 16v92 Detroit Diesel powered Spectrum gensets. The bulk storage tanks were totally slopped up with water and algae. It got cold and the fuel supply from the bulk tanks stopped flowing into the day tanks. They insisted the fuel "gelled up". No amount of telling them what really happened would change their minds. (There was so much water in the system that it froze in the piping). Still couldn't convince them that the fuel needed polishing and treated with a biocide. So they had some dimwitt install heat trace and insulation on all the exposed piping. Now the water didn't freeze in the pipes, it was free to flow into the daytank.

Gov people for the most part are just not that bright. I had so many city electricians spew so much BS about failures. The whole electrical department liked to blame every failure on "Back EMF" every poor termination that fried was because of "The Back EMF". They get away with that horse S because the higher ups are even dumber and "Back EMF" sounds scientific and mysterious when one of the big goobers says it in a meeting