Talked to the guy that maintains cell phone site generators

[Chris142]

He said that the cell companies are terrible about maintaining their equipment. Especially the hard to get to cell sites. He said that it's common to have to back pack 5 or more miles loaded down with 8 or so gallons of oil,filter,tools and a can to carry it all out!

The cell companies tend to let them run with no maintenance until it gives a problem. He said that 1800 hrs on an oil change is common on the hard to get to cell sites.

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!

 

[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.

 

[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

 

[P10crew]

Sunny is correct they test test test. The ones I know about are air blast start. The controls are monitoring power quality and a lot of times are up and running before the lights even go out then transfer is barely a blink.

 

[GMFan]

Hospitals are legally required to test their life safety systems routinely. A cell site would be classified as an "optional standby" site, and therefore is not legally required to regularly test their generators (or maintain them for that matter). Most generators are set to "exercise" once a week automatically, where they simply idle. Idling a generator with no load is generally not a good thing to do for long periods of time, as it causes "wet-stacking." Mission critical facilities, and facilities legally-required to maintain generators will typically "exercise" the generators either on building load, or with load banks.

 

[KJSmith]

They run at 1800 rpm.
They are tested monthly, usually for an hour under load.
They try to do a 8 hr run before hurricane season.

Oil changes are every 100 hrs.
Fuel tanks are sized for 100 hr runs.

They can be inside or outside.
Usually have electric block heaters.

Maintenance isn't what it used to be.
In the past, the fuel was polished at least once a year,

Most gen sets have very little run time until a storm hits.

 

[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.

 

[Skippy722]

Originally Posted by ctechbob


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.


There is nothing better than the sound of a Detroit diesel!

 

[Delta]

There's lots of equipment that as soon as it starts it's "WOT." We have a Caterpillar 16 cylinder generator at work (thing's a beast, has to run the whole plant) that is run 20 minutes bi-weekly. As soon as you put it in run it's full load. They are pretty good with maintenance though, thing gets oil changes when it barely gets 30 hours a year.

 

[dnewton3]

I used to supervise the maintenance of stationary fire-suppression-system pump engines when I worked at Ford. Those were old 2-stroke DD engines that fired up upon demand, and went WOT the moment they were live. We had to test them monthly. We ran them under load by pumping the water from the water storage tanks back into the tanks via a bypass loop. There was a sequential set of four pumps; the first one was electric (non-fused BTW) and then the three DDs came online anytime the pressure dropped below prescribed limits. One time a 20" high-pressure main supply line burst and the entire system came on "live"; that was about 12k gallons per minute pumping into the cafeteria. The DDs were impressive! There's something that makes one's skin tingle when a cacophony of DDs are running full-tilt under full load! It's inspiring, if you're into that sort of thing.

I do have a question about the conditions the gentleman described to Chris142 ...
If they have to carry in (backpack) all this maintenance stuff, then how does the generator fuel get there? Do Sherpas carry it in 10 gallons at a time? Is it flown in via helicopter? Are these cell-sites only run by generator upon back-up conditions, or are they powered continuously by the generators? It seems to be that humping maintenance stuff to the generator is not the most impressive quest in this scenario.

 

[demarpaint]

Originally Posted by Chris142
He said that the cell companies are terrible about maintaining their equipment. Especially the hard to get to cell sites. He said that it's common to have to back pack 5 or more miles loaded down with 8 or so gallons of oil,filter,tools and a can to carry it all out!

The cell companies tend to let them run with no maintenance until it gives a problem. He said that 1800 hrs on an oil change is common on the hard to get to cell sites.

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!

That's a long OCI.

With regard to full throttle operation immediately after start up. A lot of OPE does the same thing, mowers, snowblowers, etc. I know plenty of people with snowblowers who start it running WOT and get to work within a couple of seconds blowing snow. These machines last decades.

 

[Tman220]

Originally Posted by Chris142
He said that it's common to have to back pack 5 or more miles loaded down with 8 or so gallons of oil,filter,tools and a can to carry it all out!


The guy was pulling your leg. As someone that used to climb cell towers... Tower upgrades, tower maintenance, requires much larger equipment that needs to get in and out. Just remember someone at one time drove a crane capable of lifting 150-250 tons to stack that tower. Our crew trucks were 1 ton trucks towing 35' goose necks. There was never a cell site we couldn't reach.

 

[RayCJ]

I work at a facility with massive standby generators. They have enclosed structures and oil heaters and pumps that slowly circulate the oil from top to bottom. The oil is kept between 125 and 150F year round. As I recall, the requirement is sub-10 second response time between outage and switch-over to backup. The generators need to start-up faster than that to synchronize and meet the overall system requirements. They are beasts... V16 diesels ... 6 of them. Don't now for sure but they're probably 2MW each. Fuel storage tanks are the size of small grain silos.

Ray

 

[dadto2]

This isn't the case for all of the generators at my company, but the really big ones at our data centers are buffered with UPS, we can run on the UPS for 30 minutes after losing grid power. The generators do fire up instantly, but I don't know that are at full power immediately. We also have enough diesel stored on site to run the entire building for 3 weeks, or just the data center for 6 weeks continuously. Our fuel supplier regularly tests and polishes the stored fuel. The units all run for 30 minute weekly test.

 

[OVERKILL]

Originally Posted by dadto2
This isn't the case for all of the generators at my company, but the really big ones at our data centers are buffered with UPS, we can run on the UPS for 30 minutes after losing grid power. The generators do fire up instantly, but I don't know that are at full power immediately. We also have enough diesel stored on site to run the entire building for 3 weeks, or just the data center for 6 weeks continuously. Our fuel supplier regularly tests and polishes the stored fuel. The units all run for 30 minute weekly test.


Yup, that's a very typical setup. Everything important is buffered with a UPS so that the transition to standby generation is smoothed.

In terms of what the standby systems are comprised of and whether they are inside or outside, it varies wildly. Last hospital I worked at in Cali, it had a single diesel genset outside, as it wasn't a huge building. Some of the larger facilities will have several. I've only ever been at a few where they were inside, most are outside and are basically a shipping container. These can be swapped out relatively easily if needed.

 

[Schmoe]

I manage 42 emergency gensets here and also for clean air act compliance. If those gensets that have 1800 oci's are in California, I'd call Bull on that. California is the WORSE state to keep compliance for the clean air act. That company would have been fined to death if that really happened. Emergency generators have super strict regulation and record keeping requirements. Change engine oil every 100 hours, air filter every 250 hours, spark plugs every 250 hours and belts UNLESS the manufacturer has a stricter requirement. Those generators are EPA compliant only if they are kept maintained. If they are not, California Air Resources Board, CARB, will shut you down and fine the heck out of you. Fuel too has to be certified. If they are getting away with it, it's just a matter of time. New fines are now 92,500 dollars per day, per violation.

 

[ragtoplvr]

Critical installations have a bank of usually lead acid batteries on a UPS that can take the load for a while.. Examples of a critical loads are operating suites, intensive care equipment, chemical processes, data centers for banking etc.. Less critical loads are general lights, HVAC, freezers. Noncritical loads are parking lot lights, general lights, office lights other than the emergency lights. Most larger hospitals have several generators, any one of them is sufficient to run the critical loads. Then if there is a failure to start, no one dies. There are emergency services that have generators warehouse ready to run, within the contracted deliver time. They also make supplemental HVAC with giant hoses that can be installed to keep a building habitable. All hospitals and banks have to have this.

Now in the Joplin tornado, there was no point. The hospital was NOT useable. Memorial Hall was the emergency treatment location, it it had massive generators paid for by civil defense. The after triage and emergency surgery the survivors were transported to other hospitals and surviving nursing homes. There were patients on gurneys in the halls. The national guard, ems within 500 miles, Fema and lots of other government agencies did a wonderful job. Many locals took in homeless as needed. There were lots of Dr and nurses that worked for a week or longer with only cat naps.

Rod

 

[WyrTwister]

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.


Hospitals are required to do engine runs , at least , once a month . Their engines may be inside . The ones I have seen are .

As for as TelCos , they also do engine runs at least once a month . Their engines may or may not be outside . The ones outside may or may not be in an engine enclosure .

All the engines I have have shore power to keep the batteries charged and engine heaters ( usually coolant heaters ) .

I have no doubt the full load starts are not ideal on the engines . But that is part of the reason they are there . And it may not be 100% load , depending on how much the engine is oversized .

Not uncommon for a load bank to be part of the installation , at least on TelCo engines .

I worked maintenance at a hospital , ages ago . They had two 120/208 engines for the old part of the hospital & a 277/480 engine for the new part .

The 120/208 engines were paralleled through a parallel board . They were so oversized that one could easily carry the load , and still not bring coolant temp up to " Normal " . They had to have Onan bring in a load bank , to bring coolant temperature up to " Normal " & get the rings to " set " . Then repeat on the other one .

 

[john_pifer]

What does it mean to polish fuel?

 

[AlaskaMike]

Here in AK, very few cell sites have generators, regardless of whether they're in a remote area or downtown Anchorage. They will typically have a small UPS that can support a couple of hours' runtime, but that's it. Generators are typically only installed at sites that support critical infrastructure, and they have coolant heaters that keep them at 120+ deg F constantly. I'm extremely surprised that telcos in the lower 48 would maintain generators at cell sites.

Here's a photo of the data plates on a 350 KW generator at a site that was built in the mid-1960s. The generator is from the 1980s I believe. This facility does include a cell site, but it also supports stuff more critical than a bunch of millennials posting on Facebook.