Talked to the guy that maintains cell phone site generators

[Reggaemon]

I did a couple health care facilities. V 12 twin turbo Cat engines. They were on an auto start once a week, one hour at full load.
Year maintenance was all filters and oil changed. Oil samples were taken and analyzed. Power failures were a rare occurrence
so oil changes were done at 50 to 150 hours. At 35 years old they are still like new.

 

[AlaskaMike]

Originally Posted by john_pifer
What does it mean to polish fuel?


That's typically on a diesel engine where you have a separate fuel circuit, independent from the engine with a pump to filter the fuel. I have no first-hand experience with these systems, but I've mostly heard of them used with marine diesels.

 

[Mad_Hatter]

Originally Posted by Chris142

He also said that he also maintains generators for hospitals. He said that when the power goes out that generator has to start from dead cold to fully online in 8 seconds! No warm up. No ramping up to speed just wide open and full load immediately.

I have seen posts here where people were worried about entering a freeway on a cold morning and the engine was not fully warmed up. Ain't got nothing on these poor generators!

You're talking apples and oranges...

Stationary equipment turning low, fixed rpm's, fixed heat, fixed load are different beasts than high rpm vehicle engines that have variable loads, varying temps and varying operating conditions. Industrial machine lubricants often have low VI's because of this.

For example an industrial sowing machine can run on a straight 8, 10, 15 or 22 grade lubricant. The fixed operating conditions, load and temps allow for a low viscosity straight grade which flows super easy at startup.

 

[KJSmith]

Originally Posted by john_pifer
What does it mean to polish fuel?


The other answer was mostly correct.
We had portable equipment.
Remove water, filter fuel and add algicide.
Takes awhile, cleans up nice.

Sometimes the fuel can be in the tank for several years.

 

[RayCJ]

Originally Posted by AlaskaMike
Originally Posted by john_pifer
What does it mean to polish fuel?


That's typically on a diesel engine where you have a separate fuel circuit, independent from the engine with a pump to filter the fuel. I have no first-hand experience with these systems, but I've mostly heard of them used with marine diesels.


Polishing diesel fuel involves various forms of filtering along with possible analysis and additive restoration. Diesel fuel can actually get contaminated with a type of bacteria (folks tend to call it algae) that breaks the fuel down. Storage containers that sit for a very long time need to be maintained. There are mobile services that do this. In some cases, the service will simply draw-out a percentage of the tank and fill it with fresh fuel to keep it alive. Many different strategies and services are available. Marinas and yacht yards where boats are kept on the dry for long periods will have several such services available.

 

[blupupher]

Originally Posted by Reggaemon
I did a couple health care facilities. V 12 twin turbo Cat engines. They were on an auto start once a week, one hour at full load.
Year maintenance was all filters and oil changed. Oil samples were taken and analyzed. Power failures were a rare occurrence
so oil changes were done at 50 to 150 hours. At 35 years old they are still like new.

I know the hospital I work at does weekly generator tests (generator starts and runs for 1 hour, no idea if under artificial load or not), but I do know once a month they do a switch test and run the hospital emergency outlets off the generator only (red plugs and switches are generator power, what all critical equipment is supposed to be plugged in to, and half overhead lights are generator power, as is the HVAC).
No idea on what they are or maintenance schedule. They are outside behind a big wall, so can't see them. I think they run off CNG (seems I heard one of the maintanance guys mentioning it) though.

 

[JTK]

I wonder if there's any repercussions against cell phone companies if one of their towers goes dead other than pee'd off customers?

 

[Andrew1972]

These Generators spend the vast majority of life not run except exercising themselves.

 

[Jarlaxle]

Originally Posted by ctechbob
Originally Posted by Sunnyinhollister
Originally Posted by Danno
I don't doubt the cold start to full throttle in 8 seconds is rough, but how often do the hospital generators have to do that, and I would assume they are in a temperature controlled building, where a cold start, really isn't that cold.

In my area a cold start is -40F.


I believe they test them monthly


Yep, same requirement that we have at our jail. I love the noise that big Detroit makes when they blast it full throttle first thing in the morning. Tested once a month, full power run.

Earlier this year one of the control boards died and it wouldn't run. Regulations require 24/7 available power, so they had to truck in a giant portable and connect it up. I'm sure that cost the county a pretty truckload of pennies, but those are the rules. Took them a week to get the board and install it.


Sounds like the place my mother worked...the backup generator was a 12V71 Detroit, probably dating to the 60s. WOW, what a sound! I heard it under full load once (power failure due to a storm), and that was LOUD. You could hear it halfway across the parking lot, and the building it was in, you could feel the vibration through the floor.

 

[KJSmith]

Originally Posted by JTK
I wonder if there's any repercussions against cell phone companies if one of their towers goes dead other than pee'd off customers?


Cable companies or cell companies... I don't think so.

Traditional phone companies, yes.

 

[dlundblad]

I do think the abuse these things can see is quite impressive. The ~300 employee machine shop I used to work at had a Cummins powered diesel generator. Dead cold to running the entire plant in seconds.

The thing sounded like a combine.. No idea on the fuel consumption, but I'm sure it's cheaper than no production.

 

[KJSmith]

Typical fuel consumption at full load is.075 gallons per KW per hr. If I remember right and I usually don't.

A lot of our sites have 425kw gen sets.
A little under 35 gallons an hr.
We typically have 4000 gallon tanks.
You fill a tank to 90% max.
That will give you a little more than 100 hr run time.

As I said earlier, 100 hrs is the required oil change.

Most of our sites are not fully loaded.

 

[Jarlaxle]

Fuel consumption of a 12V71 Detroit at full power..."the whole bloody tanker truck" comes to mind.