Battery Backups and UPS
Вставка
- Опубліковано 15 жов 2023
- I'm talking with Xrey from Los Angeles about backup power solutions.
I recorded this interview with Riverside.fm. If you'd like to record content like this, sign up here: www.riverside.fm/?via=socalbr...
FOLLOW THE ADVENTURES:
Instagram: / socalbroadcastengineer
Facebook: / socalbroadcastengineer
Join this channel to get access to perks:
/ @thebroadcastengineer
Get some cool SoCal Broadcast Engineer merch, because, why not?
shop.spreadshirt.com/socal-br... - Наука та технологія
I have 2 CAT / Active power Flywheel UPS units here on Mt Wilson. They are very large each have two wheels 600 kW units 480 Volt and LOVE them no battery issues . Run time is only a couple minutes so you have to have good hospital grade generators. These units have been running over 20 years with very little problems. Getting ready to replace them with new units due to parts are becoming end of life. We will be using flywheels for the replacements .... Another plus is no battery fire protection needed.
One note was these were the only ups that did not mind the big Comark IOT Tube crowbars....
Flywheel UPSes are a strange thing to me. It makes a ton of sense from the science.
@@TheBroadcastEngineer IBM made some with an integrated Perkins diesel engine as part of the rotating mass. Engine coupled with a flex coupler to the flywheel, and with an electric oil pump for startup, which was then switched off when oil pressure from the engine oil pump came up, to provide oil flow on all the bearings, generator and engine. engine ran all the tip with no fuel, and with valvetrain pressurised into decompression, so it was just a poor air pump, but had full lubrication on all parts. On power failure flywheel alternator generator would see power fail, wait 10 seconds, then turn on fuel and valvetrain, so the diesel would take over and spin it up the 1 RPM to maintain the load, so no spikes, and no sudden slews in phase either. Power comes back, unit is automatically synchronised with mains again, then contactors close to apply power to the synchronous motor side, and the fuel is cut off, the engine stops delivering power, and the valvetrain is again disconnected.
Exceedingly expensive, but IBM did sell a pretty big number of them to data centres and telcos, to power the mainframes they had, and they were big enough to run an entire data centre easily.
@@SeanBZA Wow! I never knew IBM built some.
@@TheBroadcastEngineer Remember that IBM used to supply entire data centers, including the building itself, as a turnkey operation. You contracted with them for a 20 year period or more, and got a fixed monthly price with escalation clauses, and guaranteed uptime as well, plus programming and support. They were the original cloud compute service, in that you rented all from them. They just got too big and not nimble any more, and got the death of a million cuts.
Even now they are still a giant, but are a shadow of the former self, having shed all sorts of divisions off to try to stay relevant, though the one thing that should long have gone was the clotted top layer, who basically kept on with the past, and never adapted. they now are firing the experienced workers, and hiring cheap staff, with no knowledge on the product, and are loosing money and market every year. but still trying to follow the old ways, while they could have been bigger than AWS and MS combined, if they had taken even a small amount of risk and gone hard into that market space when it was small.
@SeanBZA I totally forgot about that!
Even AWS and MS are slow to move at times. When you get to a certain size the bureaucracy takes over.
Right In my wheelhouse. Here we go.
My background is 30 years in telco/cellular though so I have a different perspective. I've installed those UPC appliances before for workstations and a few for small microwave hops but the vast majority of my work is with -48v battery plants. Back in the day when analog phones were still a thing those base stations ran on +24v but all of that is gone since 09 at the very latest.
I guess fm/am xmitters and all the required equipment feeding those xmitters are all AC line voltage so my preferred UPS schema starts out converting(rectifying) shore power to -48v DC and the equipment is powered from that. If that equipment is available with -48v DC power supplies, that's ideal but it sounds like an inverter would be required to convert that -48v back to AC for whatever equipment doesn't have a DC option. That's extra cost and also that will drive up your power bill rectifying to DC then inverting back to AC, because thermodynamics...
I believe it's worth it if you're powering mission critical devices. Public safety is also a function of commercial broadcast radio... With the DC plant architecture, all your loads are running parallel to the battery system. When the AC fails, there's nothing to switch. Everything is already connected, the rectifiers just drop out of the picture. The only switch in the circuit usually(if equipped but fairly common) is an LVD low voltage disconnect. which disconnects the batteries from the load when the voltage goes below a certain threshold. Which damages and possibly destroys the batteries. That's how you reverse a battery's polarity, discharging it too far.
This architecture since the systems are so modular lets you decide how much backup you want(hours or enough to cover the genny spooling up) and also you can expand the overall capacity easier with many systems. You can start with a system that has space for 6 or 8 rectifiers(or more) but only have a load needing 2 rectifiers. Leave those other positions unpopulated until you need them. Unneeded rectifiers aren't using power that way and wearing out. You do want an N+1 population of rectifiers though. That Marconi plant you did a video on replacing rectifiers, you can add additional rectifier and distribution bays if it's ever needed.
I'm a bit old school on the batteries. I will die on this hill. Tank cells are the way. Take care of them and they will outlive you. VRLA and such are compact and less intimidating but the Tank cells will be there for you.
Forgot to add, you can't ask for a cleaner power supply than a DC system. Any surges are soaked by the rectifier on the AC side, the load will never see it.
I'll have to qualify my sermon to say I never had anything to do with the larger Liebert data center scale UPS systems. They are industry standard on the data center side.
@@davewood406 When we built our now-gone Glendale radio facilities, we had a wall-length Liebert UPS that backed up the studios and fire, life, & safety on our floor. In addition we had a building generator that only ran our two-floor suite and 2 of the 6 elevator cores + f/l/s systems. Don't recall it ever going on-line in the 5 years I remained. It just received periodic maintenance, and perhaps went on-line for a rare overnight building electrical cutover. If it did, it was a non-event.
Another major L.A. radio station inherited the same Liebert ups from an ex-mobile provider when they moved in and built a back-up facility on Mt. Harvard. It's big enough to run their s.s. transmitter for a good while. It's easy to see why it was left there.
Yes line interactive double conversion UPS are the best
UPS not beeping, because you can turn that off when you are using a cable to communicate with it. Helps a lot to stop that annoying beeping, and makes life easier. Yes many people do not connect the UPS to a computer, and you get software that can provide monitoring for a few of them, so you get a little better view of the site.
I use an APC that I got for free, dead batteries, and put on an external battery bank. Surge protection would always add on extra, on the input to the UPS, as an extra layer of protection is always good. Input surge protection is good, but you also need per unit ones, so that the primary handles the big surge, while the smaller ones, at the end of the thinner equipment cables that provide the impedance they have to have to work properly, will clamp the spikes down to a manageable level.
With batteries that 9V Durahell has 6 AAAA cells in it, and yes they do leak just like the AA and AAA cells. Lead acid battery will happily charge in reverse, because the plates are symmetrical, and the charge builds up on the one plate, so you can make it flat, and charge in reverse with the battery still giving full charge. The 7Ah lead acid batteries, commonly called alarm batteries, also loose water, so you do get them that, on removal, they rattle, and also the terminals get acid build up, so if you deal with them a lot, you always will carry around a few dozen crimp on terminals, plus some heatshrink in red and black, that you shrink on the terminals to provide extra protection and polarity marking. Those lead acid batteries always are recyclable, any scrap yard will take them no problem.
Bigger UPS units, the ones that come as a table size units, you have lots of 7Ah batteries in racks there, so changing out the batteries you first go and order a gross of batteries (144 of them, to fill the complete unit with 4 banks), and then make yourself 100 new wire links, because half of them will be corroded on opening that tray, and then you do a remove and replace on the bays. Then you have the big noise when you are powering up the batteries, as the fuses are the disconnects, and they make a rather big noise when you push them into the closed position. Oh yes, you also have to change the fan, because it runs 24/7, and after a few years it fails. Powered from the output, and with it's own fuse, though you unfortunately have to remember that the neutral is not fused, and will trip out the UPS on ground fault if you happen to let it touch any of the metalwork.
Great information, Sean! We have an outside vendor who monitors our connected ups units and servers in T.O.C., or so we thought. We just discovered one ups failed the other day that escaped them. Luckily we installed ats units, otherwise the failed ups would have taken down an entire rack
You can adjust the UPS to let dirty ac through
Out of curiosity, why would you want to do that?
@@TheBroadcastEngineer to make it charge and pass power once generator has come on