Ready made rectifier

[Shadow]

I have quite a few of these large rectifiers(8 of them so far)as used by Telephone companys for there battery back up systems.They are fed either 120 or 220 volt AC, which is rectified to 48 volt DC.These are all set to charge up to 52.4 volts, have high and low voltage alarm, float, equalize settings,and lots more.So far I've just used a couple for parts, gauges, heat sincs,100 amp fuses, shunt for amp gauge.Theres alot of parts inside.

              I was told if I tried hooking one directly to my wind turbine, the problem I would have is frequency. These are made to accept 60 hz. And mine would be a variable frequency. Is this the case?

              Next question, there are 4 large capacitors inside each one. (at least I think they are large lol) One is 60,000 uf 75Volt DC, one is 22,000uf and 2 are 17,000uf 65vdc.Can these be used in a wind system some way? I'm not sure how capacitors work exactly but could they used with heat elements? Wind charges up capactor,which in turn dumps power to an element? I dont know.

I just know they seemed to good to scrap.

They are fairly heavy, about 120 lbs each.

Theres a couple transformers in each unit, one is about the size of a small block Chevy. Thats where all the weight comes from.

The reason they are replacing them? Because they are not Digital! The employees have trouble recording the readings on the gauges.lol go figure.

[zap]

Whenever I see pictures like this of nice finds, I always wonder how many keyboards end up being trashed from drool.

[Opera House]

Looks like wedges in the center of the transformer.  That tells me that it is ferro-resonant and will only work at 60 Hz, even though I don't see the associated oil cap that would connect right to it.  Everything else would be fine to use.

[TomW]

Shadow;

Lots of goodies in those units, seems a shame to part them out tho.

I will give you $1 for any one of them.

As far as direct connection to a turbine I always thought if you put motor run caps in each line feeding a transformer you could, indeed, use standard A.C. transformers just not at peak efficiency. The caps would keep the primary windings from loading the mill until there was some speed on the prop or I think so.

Cheers.

TomW

[DanG]

-LOL- Reminds me of my old manager bringing in an old electro-mechanical counter he used on his home security system & me asking if he had another one, he got all snooty and denied me the trinket. That evening I walked up to local telephone company substation (disguised as a house) and looked in their dumpster...  The were converting to all solid-state and were trashing their spare parts, the next morning I went to work carrying a box of 20 brand new electro-mechanical counters!

I'd keep one as is & cannabilize the others & ebay the bits to support zeroing in on best system I could afford...  Those Xfrmrs are tuned for 60hz resonance, at low current who cares, but approach a medium-high load and you could smoke up a string of components...

[DanG]

And I seem to recall ferro-resonant xfmrs MUST have a load on them when connected to source or you can fry windings.

[RP]

Is it possible that the wedges are there simply to increase air cooling of the windings?

[richhagen]

Shadow, those would be really great for someone with a 48V system that needed a charge controller for charging from the grid if the batteries got to low.  As a matter of fact, I would love to have one of those myself.  The local utility here uses the same brand for there backup battery banks, but at a higher voltage.  They buy the most reliable components available from what I can see, and cost appears to be only a secondary concern.  I could be wrong, but I would think those would have significant value in one piece.  Rich

[Drives]

RP:

I have many transformers that have wooden wedges, and are not labeled ferro-resonant.  I believe that the wedges are for allowing cooling air flow, and vibration isolation.  I also have some small, oiless, 1-2Kva ferro-resonant control transformers, they seem very heavy, as if they had extra laminations in them.  I could be wrong.

Shadow...nice unit!  

I'm guessing if you could get a full schematic of the unit, you could trace out the secondary of the transformer to see it feeding a rectifier unit.  Couldn't you then feed the output of your (48v designed) genny to the rectifier, and disconnect the transformer?  It looks like you would still need a source of 120Vac 60hz control power for the electronics on the PCB, but this would make a very nice unit for a windmill.  The schematics would help greatly.

Just a thought.

[Shadow]

Yes they would be ideal hooked to the grid. I gave one to a freind and he's hooking it up as such. I have a 48 volt system but not close to the grid,but would be nice if I could feed my wind turbine into it and use it for rectifier/charge controller. I think I found some refurbished ones on the net somewhere and they were asking $1100 or something crazy. Goes to show more gov't waste, before I spoke for them they would take them to the scrap metal yard and roll them off their truck into the pile!In fact I bought the first one there for 20.00.Then I contacted the rep and he said we'll set them outside the door and you come pick them up.Not sure where you are Rich, but theres one here with your name on it,may cost a fortune to ship though.

[Nando]

DO NOT DIS-ASSEMBLE ANY UNTIL YOU AND I TALK ABOUT THEM.!!!!

They do not look like they are ferro-resonant chargers. ( the ones that can not be connected to a wind mill)

I am visiting a place right now, so I will send a message when I arrive to my computer to define if those are good for limited variable input frequency.

Nando

[Nando]

The wedges are for air cooling. quite common with these type of chargers to reduce winding heating.

If the charger is a ferro resonant type ( old SOLA type) it needs to have a high voltage AC capacitor to resonate at 60 HZ with one of the windings.

Also the transformer has at least one magnetic choke SHORT between the primary, and the resonant winding ( also the 48 volts secondary).

The 2 or 3 photos show the transformer with a front plate -- the primary is in the lower part of the transformer and immediately above the winding, it seems that there is either an isolator or a group of laminations that run from the left leg of the transformer, to the center leg then from the other side of the center leg to the right leg.

You need to tell me if that center part is metallic or not it it is metallic then you may have a saturable ferro resonant transformer -- the you need to find an OIL type capacitor, probably 600 volts AC rated and the capacitance medium value ( I do not know the power output to define the capacitor --or the input voltage ).

Certain types can have the capacitor removed as well as the shunting magnetic short and behave like regular transformer BUT the regulation will not be effective.

Nando

[Shadow]

Nando, This rectifier is disassembled to much to ever put back into use anyway, so tomorrow I will remove that transformer for closer inspection. I will take some more pictures. Actually  tucked in behind that transformer is another capacitor that I can read either 600 or 800 volt AC, and what appears to be 15.0 uf.  Also below the big transformer and to the right of, there are 2 more transformers about 4 inches by 4 inches.These all appear to be the same so whatever I learn on one will apply to the rest.

[richhagen]

saskatewan if a bit of a drive from Chicago, so a day trip is probably out.  Drop me an e-mail, I would be happy make any necessary arrangements.  Rich

[mlz]

Hmm, if they are anything like the ones we had at USWest, it is a FR transformer, you probably will find an AC cap either behind the XFMR or down in the lower right hand area.

REALLY watch those caps.  I've seen a few hold a charge for a few months, one zap and you'll remember to check them first next time, unless you have a bad heart, and it might be your last.

The transformers probably won't work for you, but there are TONS of goodies in there you could put to use, not the least that nice casing!

[Nothing40]

I've seen transformers with magnetic shunts like that before..Mostly in microwave ovens.The transformers run 'warm' to 'Hot!!'

The shunts help with voltage regulation..

Might be interesting to knock the shunts out of one of the trannies,and play around?

Be careful though,as the shunt-less transformer might draw more current,or have a much larger turn-on surge.

I've gotta go wipe up my slobber..

[terry5732]

Green

[tecker]

 Hook me up . I'll give a good price .Put em on ebay . My ups are down till I get a new spot built I could shuck them all and one of those could move right in.