Why is battery backup the only option?

[holler]

In cities such as Huntsville,Phil Campbell,and Arab along with many others the outdoor warning sirens were all that were left and they did their duty magnificently

None of the sirens in Huntsville are battery backup, all AC only.

[Unit of Civil Defense]

The biggest drawback to generator back up ...as what has been discussed already...is maintenance, or the lack there of. I spent 7 years in the Army dealing with generators as that was my M.O.S (Military Occupational Specialty)...I have seen the good, the bad and the ugly as far as generators are concerned.

The standards that I went by, whether is was a gas or diesel fuel unit, was that the generator be operated NO LESS than at least 1 hour a month with a load....Preventive Maintenance Schedule. This standard was to insure that the gaskets where kept pliable and did not dry out as well as to help prevent the build up of moisture in the fuel tank and oil pan....the load portion was to insure that the generator side of the unit was still in phase at 60 hz cycles.......not every generator was maintained this way and some failed in the field as a result.....fun times!
LP gas units have less of a chance of moisture build up in the bottle , but have as much chance if not more of moisture being built up in the oil pan and upper cylinder area of the head(s)
With all that being said, I have my doubts that any municipality would be willing to do what it would take to keep the generators running at peak performance year round....where as the deep cycle batteries or UPS that are being used get changed according to what manufactures say is the life time of the batteries or UPS. Fuel that is allowed to sit for months or years eventually turns into varnish.
Generators are easy to ignore and forget about...my own generator here at home is in need of some maintenance....have not done anything with it for a couple of years.

[DJ2226]

Are the 2001s out that way solar powered? Solar powered sirens can be installed pretty much anywhere, no? I would imagine the installation would be a bit easier to deal with since the power company isn't involved, and the siren could be powered up the day of the install.

[Andys Live WX]

In my opinion a great minimal maintenance siren is the 2T22A. It is very basic in that it only contains 3 moving parts. Probably the most simple and reliable of all omni-directional sirens every made. No brushes, capacitors, springs, battery chargers, or batteries to go bad. It can even be retro fitted with modern controls to follow code and what not.

Jeb also has a good point with Thunderbolts. It seems as though people in society now days are too lazy to get off their 3 letter word and take 15 minutes at the most to check oil levels, belts, and operation. This is really sad. Everyone thinks you buy a new siren and it will last forever without any maintenance. THAT DOESN'T HAPPEN. Any mechanical siren will require maintenance overtime, but putting in 15 minutes of your life will lengthen the life of your siren, I guarantee it. It will save you lots of money on major repairs later.

I agree with Eric, battery back-up is not cost effective since all batteries have a shelf life, and very rarely will they ever be used because there are not tornado warnings everyday. So even though those batteries that have sat for 5 years in that cabinet unused, doesn't mean they are able to hold charge if the cells have dried up. Then it costs money to replace those batteries. You are basically throwing money out the door at something that never gets used. If the power goes out, it's not the end of the world. Back in the day there were never battery back-up sirens and everybody got along fine. And what if a lightning bolt hits the incoming power lines? The first thing it's going to take out is battery chargers and PCBs. Even just a regular voltage spike is enough to mess up a PCB.

[freebrickproductions]

In cities such as Huntsville,Phil Campbell,and Arab along with many others the outdoor warning sirens were all that were left and they did their duty magnificently

None of the sirens in Huntsville are battery backup, all AC only.

If I recall what emofficer told me back in May correctly, only two sirens in Madison County, AL's system have batteries. The rest are AC only (except for maybe the ones on Redstone Arsenal).

[metalstorm]

My bad on Huntsville I thought their 2001s were battery units. Still many of the cities had only their battery backed up sirens to rely on on that day.

[archangel_cpj]

I think anymore I move 70 percent AC and the rest are battery back up 16V1TS mainly... I personally like AC sirens especially for smaller communities and tight budgets... Say you have a community who gets a grant for 5 or six sirens... They want maintenance free and may not have a budget to replace 6 200 dollar batteries per unit every 3 - 5 years... So in this case you can throw up AC sirens and for all intents and purposes they can stay there for 25 plus years with no maintenance at all... If you have a brushed motor that's another story... But then you hear the what if the power is out????? My thinking is that most of the time the power is not out before the storm and the word EARLY in Early Warning System is key... IF you have sirens there should be someone or a PC watching the weather and get the units activated before the power fails... Now a qualification if your power grid is held together with duct tape and baling wire and it fails every-time it blows a bit AC/DC is the way to go... A good consultant treats every community as a unique entity with different needs and priorities and works to fill those with the budget allowed... There always has to be compromises... The biggest reason not to keep older units in a system comes down to duty cycles and brushes... Will a community pull that unit down every few years to re-brush it and does it have bearings that need greased etc etc... Most will not and when it fails it will sit there for years until something happens to make the administrators remember it is broken... I liken sirens to silent sentinels most folks forget they are there until they work or don't work and you can be a hero or zero real fast so make the administrators job easier if they can swing the extra maintenance of AC/DC go for it but if they likely cant AC is better...

[holler]

I agree with everything you say except for the duty cycle part and the brushes. Brushes only apply to the single phase federals and the tbolt/model 2. They can be changed without removing the siren head. Plus the brushes last a very long time with at least 10 years of service life on a good commutator. Pretty much the same service life you get out of a set of capacitors on an induction single phase motor.

Bearings on the majority of your old sirens are non greasable anyway, either shielded or sealed just like those new sentry sirens you install. The only greaseable bearings I have run across are on OLD sirens (pre 1950s), everything else has been sealed or shielded. Those that do have greasable bearings get new sealed bearings so they are maintenance free.

As for the duty cycles, those old sirens are pretty tough, especially the three phase ones. We had a three phase STH-10 take a lightning hit and run for almost 2 hours straight until somebody went out and turned it off. Didn't hurt the siren, just fried the FC and burned the neutral wire up in the disconnect.

But you have a very valid point about the often overlooked three phase omnidirectional siren, and I have been saying the same thing for years.

[archangel_cpj]

Id pay attention to the duty cycle I had an old model 5 a client rebuilt and it blew the armature clean off because the client ran it 15 minutes at a time Id never seen that before the motor shop had said it was from overheating due to the cycle most of those old motors were a 10 min max run time and then a 50 min cool down...Saw a rebuilt M10 do about the same thing but I think that may have been a lightning strike They were also cast iron and that ended up being a huge heat sink and hence the long cool down...Ive always been weary of brushes Im finding that alot of folks are not happy with the just spin it up once for a tornado warning alot are running them 20 - 30 minutes or the length the community is at risk then you throw in the folks who are using them for sever t storms over 70MPH and there is a bunch of run time Id bet two or three times what they did even ten years ago... Now with NWS embedding the wind data into the warnings we have folks letting the PC automatically activate the sirens for t storms over 70MPH and any tornado warning and Id bet 60 percent of my clients run them many minutes per event... Ive been in the deal for 15 years and the last 5 - 7 has seen a big increase in tech and warning lead time hence the longer run times...The biggest issue with bearings in general is lack of a weekly test the grease in hot weather can get thin and settle in the bottom of the bearing and over time in high humidity a bit of condensation happens can shorten bearing life...

[holler]

How old was that model 5 that smoked? Was it a later model or one of the old cast iron pigs? All of my clients run 3 on/ 3 off for warnings, with the majority of sirens being 2001s.

We've found the Marathons to be really tough. They are a more modern motor and cool down pretty fast. The big single phase motors on the other hand would throw the commutator out after 30 minutes run time.