WANTED: 50hp Phase Converters - - - Tax Deductible - - EAGLE SCOUT Gov't Service Project

Hello, First of all let me take this opportunity to thank all of you who by virtue of reading this line have taken time out of your busy lives
in order to do so. I thank you profusely. I am working towards achieving the highest rank and honor of scouting, by becoming an Eagle Scout through completing a project as part of the Boy Scouts of America program.
My project is rather complex in nature and by virtue of this fact has been difficult to accomplish, with forecasted expenses the government gave us that come in well over $50,000. For my project we are going to take two Cold War era civil defense sirens and install them in a small rural community in Arizona north of Phoenix called Mesa Del Caballo which is near Payson Arizona, just for a reference point for anyone who is actually from Arizona. This is a small mountain community surrounded by the forest. Arizona has been going through a massive drought over the past years, and as a result, combined with the disastrous effects of the devastating bark beetle, our forests have been highly susceptible as of late to pernicious wild fires. My goal is to set up these two sirens in this community, one on one end, one on the other, such that if there ever were a forest fire, or other disaster which required a quick evacuation, the entire town could be alerted via these sirens which would span all distance and language barriers.
The government has been extraordinarily helpful to my project so far by letting us borrow two civil defense sirens each valued at roughly $25,000. Just to clear up a misconception we can only borrow the sirens per regulations that were set up before the Cold War when the sirens were originally installed throughout most of the greater Phoenix Arizona area. The sirens we are "borrowing" for the project should never need to be returned, it was just part of the original contract in case of an extreme unpredictable emergency.
The problem we have run into is that we now have two Cold War era civil defense sirens, but we don't have the money required to install them. The representative from the Arizona Government estimated the actual installation to be somewhere around $75,000. Our estimates upon further investigation show it to be a smaller figure, but nevertheless still a massively large amount. The two parts we stand in need of right now are two 220 volt 50hp phase converters to go from 1 phase to 3 phase. These would be tax deductible, and we can provide proof of their purpose for this project upon request. We are looking for a spare 50hp phase converter that can be donated to our project. It does not need to be new, used or surplus is absolutely fine. The exact specifications of the civil defense siren are below:
We are starting off with a 220 volt, 200 amp, 1 phase line. The siren we seek to power has three separate motors. Motor 1 is a 7hp Motor 2 is a 4.5hp Motor 3 is a 1.5hp RLA is 89amps, 220 volt, 3 phase
I was told by a specialist per these specifications that we needed a 50hp phase converter. If anyone has a spare they can donate or knows of a possibility for a donation, or can point us in the right direction, or has any other helpful information for the project we would deeply appreciate every little thing we can get at this point! Thank you for your time in reading this letter. I deeply appreciate it. In case my email address is blocked as I have begun to notice that many usenet services do, I will spell it out here. It is: jkeagle13 at aol dot com
Thank you!
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I have a 40 HP one on ebay right now. It is going to sell pretty cheap check it out.:http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item862006851&ssPageName=STRK:MESE:IT
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On 27 Dec 2004 22:15:16 -0800, snipped-for-privacy@aol.com wroth:

---- assuming that the original poster will come back to read replies ---
    The government should have plenty of surplus mobile generators available. You know, the ones that have diesel engines and can be towed around behind a big truck. I'll bet you could arrange to "borrow" one of those with suitable output power specifications to allow you to connect directly to your sirens for free.
Jim
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A 10hp phase converter should be more than enough. I have a 7.5hp motor on my planer and it starts just fine with a 10hp unit. Also, each motor you have in the circuit running contributes to the total rating.
You should be able to buy a 10hp unit for just a couple hundred if you do it yourself. Get a pre-made panel for $250 and get a used motor for about $100.
snipped-for-privacy@aol.com wrote:

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wrote:

That would be correct for three 1725 RPM machine tool motors which can start one at a time with low to moderate inertia and no load. Several factors can significantly increase the converter size required including higher speed motors (3450 RPM), high inertia load, permanantly connected load requiring startup into full load (which often means a different NEMA design class having higher starting current requirements), load horsepower requirements very close to motor rating, a requirement that all 3 motors start at once, and probably a few other factors I don't think of right now.
Perhaps the OP can provide a bit more info on his requirements - all of the rest of the motor nameplate data including design class, service factor and speed as well as the startup requirements and the nature of the connected loads would be good. Probably however lack of available details will make this a trial and error process, and I would recommend attempting to borrow a converter for a test before shelling out cash for a converter that might be too small for your application.
Use of a static converter (by which I mean a box of capacitors with controls, not a solid state inverter) rather than a rotary converter might well require a higher rated unit also, the OP did not specify what type of converter he was referring to. 7 HP is a bit large for a single phase input 3-phase output inverter, otherwise 3 inverters would probably be the best solution.
Glen
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On 27 Dec 2004 22:15:16 -0800, snipped-for-privacy@aol.com wrote:

I would question the assertion that you need a 50hp converter for this application, especially if you can add a couple of time delay relays to the controller so that the motors start one at a time. The required size of the rotary converter can also be reduced by adding phase correction capacitors to the larger load motors. The actual size of the converter required depends partly on how much safety factor the siren designers built in; if the actual mechanical load is over 80% of the motor rating including the service factor, then a seemingly oversized converter may really be required. Your local specialist may have some information on this.
You can get a lot of good information about rotary phase converters from the rec.crafts.metalworking newsgroup - a lot of the regulars there use them for their machine tools and some of them have plans posted in an archive somewhere which they will no doubt refer you to if you inquire there, or you could find them with a search for "rotary phase converter" in the newsgroup archives on google groups. I use the design posted by Fitch (IIRC) and it works well even though I only use a 5hp converter for a 5hp lathe motor (from which I only require about 3hp output power, your application is different).
Nice project, good luck with it.
Glen
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Why not look for VFD's on ebay? Variable frequency drives are capable of doing the same thing, taking two phases and turning them into three. Being solid state, they have no moving parts, will not rust out, and are perfectly capable of doing what you need. The reliability in a system that will see rare usage I assume is pretty attractive. Take up a whole lot less space, wiring, and so forth, also. Any competent reliable electrical contractor will be able to wire one up, and if you talked nicely enough, he'll liably do it for free. Even if you don't pay more in up-front costs, shipping will for sure be a whole lot less!
| Hello, | First of all let me take this opportunity to thank all of you who | by virtue of reading this line have taken time out of your busy lives | in order to do so. I thank you profusely. I am working towards | achieving the highest rank and honor of scouting, by becoming an Eagle | Scout through completing a project as part of the Boy Scouts of America | program. | | My project is rather complex in nature and by virtue of this fact | has been difficult to accomplish, with forecasted expenses the | government gave us that come in well over $50,000. For my project we | are going to take two Cold War era civil defense sirens and install | them in a small rural community in Arizona north of Phoenix called Mesa | Del Caballo which is near Payson Arizona, just for a reference point | for anyone who is actually from Arizona. This is a small mountain | community surrounded by the forest. Arizona has been going through a | massive drought over the past years, and as a result, combined with the | disastrous effects of the devastating bark beetle, our forests have | been highly susceptible as of late to pernicious wild fires. My goal is | to set up these two sirens in this community, one on one end, one on | the other, such that if there ever were a forest fire, or other | disaster which required a quick evacuation, the entire town could be | alerted via these sirens which would span all distance and language | barriers. | | The government has been extraordinarily helpful to my project so | far by letting us borrow two civil defense sirens each valued at | roughly $25,000. Just to clear up a misconception we can only borrow | the sirens per regulations that were set up before the Cold War when | the sirens were originally installed throughout most of the greater | Phoenix Arizona area. The sirens we are "borrowing" for the project | should never need to be returned, it was just part of the original | contract in case of an extreme unpredictable emergency. | | The problem we have run into is that we now have two Cold War era | civil defense sirens, but we don't have the money required to install | them. The representative from the Arizona Government estimated the | actual installation to be somewhere around $75,000. Our estimates upon | further investigation show it to be a smaller figure, but nevertheless | still a massively large amount. The two parts we stand in need of right | now are two 220 volt 50hp phase converters to go from 1 phase to 3 | phase. These would be tax deductible, and we can provide proof of their | purpose for this project upon request. We are looking for a spare 50hp | phase converter that can be donated to our project. It does not need to | be new, used or surplus is absolutely fine. The exact specifications of | the civil defense siren are below: | | We are starting off with a 220 volt, 200 amp, 1 phase line. | The siren we seek to power has three separate motors. | Motor 1 is a 7hp | Motor 2 is a 4.5hp | Motor 3 is a 1.5hp | RLA is 89amps, 220 volt, 3 phase | | I was told by a specialist per these specifications that we needed | a 50hp phase converter. If anyone has a spare they can donate or knows | of a possibility for a donation, or can point us in the right | direction, or has any other helpful information for the project we | would deeply appreciate every little thing we can get at this point! | Thank you for your time in reading this letter. I deeply appreciate it. | In case my email address is blocked as I have begun to notice that many | usenet services do, I will spell it out here. It is: jkeagle13 at aol | dot com | | Thank you! |
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snipped-for-privacy@aol.com wrote:

Are you connected to a University or other group ?
Can you not just use a transformer ? Most of us don't have them but Universities and Power companies do. Maybe you can get a consultant to the group from the local power company.
Martin
--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer snipped-for-privacy@pacbell.net
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JKeagle
I had expected to read a response from you concerning your more exact needs regarding this "phase converter". Your project interests me, but it is unclear if you are hoping for a donation, or if you have interest in developing a power source for the sirens. I'm pretty sure you could power your sirens with a much smaller rotary converter. It could be a real learning project for some electrically inclined young scout. I'd expect a little (5 HP) idler at each siren could make all the sound you'd ever need. If this *is* a real project where only the "results" (siren sounds) is the goal, and no *overseeing specification writing group* of people need to be satisfied, I'd voluntere my time and materials to a task like this. I'd even bring some parts.
I'd sure like to hear more about what your 'constraints" are.
Jerry (who lives about a day's drive away from Payson and would be willing to drive there)

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Hmm. Yep, why does this project sound like one of those "no good deed goes unpunished" kind of thing?
1) a hit-n-run request, giving an absolute requirement, with no apparent justification.
2) absolutely no follow-up post to the folks who took the time to make comments.
3) absolutely no further technical information about the project.
4) governmental participation....
Jim
--
==================================================
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Hi! Thank you everyone for the posts. Sorry I did not respond sooner. I just recently had surgery and I had to go to the hospital yesterday for a post-surgery visit. I am highly appreciative as I mentioned in my original post to all of those people who donated their time. I am sorry it took me this long to respond.
Sadly I can't right now comment on most of the posts as I am not really an electricity person and understand very very little about any of it, so it is all Greek to me! I will pass it on to the electrician who is volunteering his time and I will have him explain it, then we both can comment and post follow-up questions but for now I am afraid I don't understand enough of what was said to say anything in response!
I am open to all ideas including the VFD idea. I have no set "has to be a 50hp phase converter". I thought that was all it could be after a call to a local shop that specializes in phase converters. I gave them the requirements and they said the only thing that would work in this case is a 50hp phase converter, nothing else, which was why I thought that is what I was set on, finding one of those. I would be happy to use any alternate solution, especially if it is cheaper. Because I have so little an understanding of electricity that is the explanation for why I gave an absolute requirement, is because I didn't realize anything else existed, but I am glad to utilize whatever works.
Unfortunately in response to one of the comments yes, their is an overseeing board. The Arizona Emergency Management Services team is closely monitoring this. We have to have a structural engineer on board, and everything must be perfectly assembled and inspected to be up to code. They didn't give the sirens to me and say, "alright, go have fun now, make them work", the Emergency Management team that deals with the Civil Defense Sirens are very much involved and oversee every step of the project so everything has to be satisfactory for them and up to code. I am not associated with any university. I am still in high school and I am working on my Eagle Scout project which must be completed before my 18th birthday in order to qualify for the award.
So I will pass everything on to the electrician. He is very busy but hopefully sometime this week he can look at the comments and we can make another response. All the technical specifications I have were in the original post. I can call my contact with Maricopa to get more of the specific details if necessary.
To recap. The fire station the first siren we are working on right now is to be mounted at has a 1 phase 220 volt 200 amp service. The siren is 3 phase, 220 volt, 100 amp. My assignment was to figure out how to get from point A to point B, and they suggested the best way would be to use a phase converter. The only other alternative they said would be to run the 3-phase lines from the local town of Payson to this rural community Mesa Del Caballo, but they suggested a phase converter would be easier and cheaper. I thus called a local machine shop as I said and gave them everything and they said the only one that could handle it would be a 50hp phase converter, based upon these requirements:
The three motors to run the siren are: Motor 1 is a 7hp Motor 2 is a 4.5hp Motor 3 is a 1.5hp RLA is 89amps
I can get further details once I know what to ask the siren specialist, but that is everything I have right now.
I would like to thank everyone who has posted and will post for their time and help! I will show it all to the electrician and respond with a better response. I am sure many of the solutions will work though, so thank you all very much, I wasn't trying to ignore anyone!
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On 29 Dec 2004 11:47:47 -0800, snipped-for-privacy@aol.com wrote:

Phase Converters may be easier and cheaper, but they're simply not as reliable. KISS is a valuable principle to follow. When there is an emergency and you hit the button for that siren, it needs to work every time - or why bother putting it up in the first place?
Check with your local power utility about those power lines going from Payson to Mesa Del Caballo, and feeding through the town. I find it /very/ hard to believe that they would run a rural power feed any distance at ALL with only single-phase, since practically all utility generation facilities (SWAG 99.5% plus) put out native 3-phase, and almost any commercial or industrial use needs it to work - including water well pumps on far-flung farms and ranches.
I'm willing to bet that when you get in contact with an engineer at the local power utility, and he checks the blueprints for the area, the 3-phase is fairly close by. And I'm sure he can show you how it all works, and go over the pros and cons of how to run those sirens.
Look at the top set of wires on the pole - if they come in sets of three, or four with one strung on a set of smaller (lower voltage) white-glazed insulators, that is 3-phase.
Where the expensive problem can come in is if they don't have the transformers available already to knock down the 15,000 or 34,500-Volt transmission line down to the 240-Volt 3-phase that you need.
If the third phase is already at the pole feeding the fire station, it gets a whole lot easier... Ask the power company to add a second transformer for a 120/240V 3-Ph "Open Delta" feed like they usually use for an elevator service. Bada-Bing, you're most of the way there.
You (and the rest of the pack) can do a lot of the mechanical work yourselves installing a second power meter and service at the Fire Station to feed the siren - I would use a 200-Amp service and oversize all wiring and breakers as much as possible for insurance, since this use is life critical you don't want any nuisance trips of the main breaker...
Just get that local electrician to show you how it's done and get you the special-order parts, then he can check your work for obvious goofs before the local Electrical Inspector comes out for the real sign-off.
Another way to do it, as has been suggested, is to get a "surplus" 3-phase motor-generator plant to run the siren - and as a bonus, it can also power the Fire Station in a power outage. You can run the control electronics, generator starting battery trickle charger and block heater off the single-phase feed to the FS.
If you stay on top of the maintenance, generators are pretty reliable, though it will introduce about a 15-second delay while it starts and comes up to speed before you can start the siren.
--<< Bruce >>--
PS: If I think of it, I'll get you a picture of the old CD Siren (abandoned in place) in West Hollywood CA, where they have an Onan gasoline engine direct-coupled to the siren at the top of the lattice tower, mounted on a big swivel bearing - no big electric motors at all, just a small 120V utility feed for the battery charger...
--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
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On Wed, 29 Dec 2004 06:13:29 GMT, "Jerry Martes"

Rotary converters are sooo 60's. Siemens, GE, Allen-Bradley among others make solid state motordrives of all types and power ratings. Basically they rectify the incoming power and reconvert the DC to variable voltage and frequency AC (user defined). This means many models accept being powered by single phase while driving a three-phase motor.
- YD.
--
Remove HAT if replying by mail.

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proposed a theory ......and in reply I say!:
remove ns from my header address to reply via email
....and sooooo cheap <G>

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So are Civil Defense sirens.
"If you see a bright flash immediately duck down and cover yourself with whatever is at hand. Jim and Judy are shown in this film using their picnic blanket for thermal radiation flash protection. _They_ didn't let a nuclear blast interfere with their outdoor eating enjoyment."
--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
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On Sat, 01 Jan 2005 20:09:33 +0000, Nicholas O. Lindan wrote:

No they are *not*! In fact they put them in in the 80's (well after I left the region).

In the midwest, if you hear a CD siren you'd better find a place to hide your sorry ass. There is a tornado right on it! They only fire 'em up if it's on the ground and confirmed, so you'd better know what to do before you hear it.
--
Keith


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On Sun, 02 Jan 2005 20:08:41 -0500, keith wrote:

place your head firmly between your knees, and kiss your ass good-bye."
Cheers! Rich
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Hi, Thanks again for your replies. I am afraid that I am a little confused on how we can use anything less than a 25hp phase converter. I am no expert here, so I am just trying to understand it myself. Just simply from browsing the internet, and eBay, it appears to me that the specialist I called was correct in the fact that it needed to be a very large phase converter. The sirens have a RLA of 89amps, and a mandatory government safety, has to exist regulation of the phase converter being able to produce 100amps.
So I am looking for a phase converter to produce 100amps.
A chart I found at the following link states that the phase converter must be at least a 25hp motor in order to generate 100amps.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&categoryA952&item863629765&rd=1&ssPageName=WDVW
So accounting this chart, can I use a smaller motor, like a 7.5hp motor, and still generate 100amps?
Also, I am getting ready to write a press release in order to gain some media attention and community support for my project. I have been persuing over the last several months trying to get APS involved, and my efforts so far have been in vain. The only returned call from APS out of many many messages, 6 or 7, possibly more that I have left for APS was simply to say I had the wrong person, which new person, many phone messages later, still won't return my calls. So the press release has many functions. A: Simply to inform the public of my project. B: To see if someone who reads it knows where there is an unused surplus phase converter at an old farm or machine shop or something, and C: To show everyone, specifically at this point APS that I am serious, and see if a newspaper article might help them jump on the project a little bit quicker. So I know the technical details of how to circulate a press release, etc., thanks to my wonderful Eagle Scout Advisor, but I am just curious on if anyone has any suggestions on what to say or how to phrase it besides the base explanation of my project. Should we leave it at simply that, an explanation of the project? Or should we try and draw public support and donations? Any suggestions would be greatly appreciated.
Thank you everyone for your time in this matter. Jkeagle13 (at) aol (dot) com
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I read in sci.electronics.design that snipped-for-privacy@aol.com wrote (in
50hp Phase Converters - - - Tax Deductible - - EAGLE SCOUT Gov't Service Project', on Sun, 2 Jan 2005:

Something doesn't make sense. Your motors total 13 HP, which is 13 x 746 watts = 9698 W, say 10 kW. This implies a *single phase* 220 V current of 44 A. To start the motors you will need a current larger than that.
100 A would be a generous allowance for starting if you were using single phase, but in the three-phase system, the current per phase is not 44 A but 44/sqrt(3) = 25.4 A, so 50 A per phase would be a generous allowance.
I think you need more technical advice *locally*, to see why you are being given inconsistent specifications.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
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I don't know where you came up with 50hp requirement. The motors themselves only add to 13hp. FOS of 2 only gives you 26 hp. There are other mitigating factors, but 50hp seems extraordinally over sized.
In any case, is it possible to change the motors out? None of these are too big to not be used as single phase motors. The biggest factor would be the mounting type. If you weren't so far away, I could probably give you at least one of each size, but shipping from my location would be cheaper to go buy a new one or close to it.
JW
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