isolation transformer

Discussion in 'Studio Construction & Acoustics Forum' started by vibrations1951, Sep 27, 2009.

  1. vibrations1951

    vibrations1951

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    Hello again. Been a while since I've posted but have been reading posts regularly. I've been quite busy for the past year plus, just trying to get the shell up and heated to the studio build. See vibrationsrecording.com even though I haven't updated it for a while now. anyway, time to get some ac power in there.

    I'll be bringing in single phase 200amps 60hz ac (local co. wouldn't do three phase even though it's a commercial service). My wife and I share the building so she gets 100amps "dirty power" to her piece (I'm also going to use that feed for my "dirty power"). I'm running the other 100amps to a "clean power" panel in my machine room.

    Both 100A feeds off the 200amp service will carry all three wires (2 hot and the neutral) to each respective 100amp breaker box. To make mine a "clean box" I want to put an isolation transformer in line before the "clean" box in my machine room to break the "dirty" ground.

    My sparky agrees that a single phase, 15kva (80% loss typical), 240/120V 100amp in and 240/120V 100amp out is desireable. This leaves plenty of room for eventual/possible growth even though I don't anticipate needing more than 60 amps total full bore at this time.

    The electrician suggested I find the right unit and he would graciously order for me so that i can pay his cost only. He's delt with these for cows/farms, not recording studios, though there may be no difference for all we know???Problem is, I've been researching for weeks now online and don't seem to be able to decide which brand/which type of isolation transformer to buy?? The Furman rigs look great but i want just one to hardwire inline before the breaker box. the Furman rig and others are too small and designed for after the box.

    So.....Toroidal iso trans., sheilded,...... Acme, Temco, GE, TSI power, Hammond power, Piltron, others???... I'm in need of some direction, suggestions???? I see many companies build to order though "of the shelf "would likely be less costly.

    You guys have been a great resource before and i hope you can help on this one.
     
  2. MadMax

    MadMax

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    I kept an eye on feeBay for weeks... finally snagged one out of Cali.

    Shipping wasn't horrible... one coast to the other... ended up cheaper by about $400 than new. It's a Square D.
     
  3. Thomas W. Bethel

    Thomas W. Bethel

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  4. vibrations1951

    vibrations1951

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    Hey Max, i have been following (drooling over!) your project for some time now. Mucho mucho kudos!!! I don't know how you have the energy to keep up with forum stuff let alone keeping the project moving ahead!

    So many thanks for your response. i've been watching "feebay" for sure but nothing quite right yet. I'll use your tenacity as a model and keep on searching. i envy your square D deal yet it couldn't have happened to a more deserving soul!

    Thanks for the suggestion, inspiration and mostly, generousity to so many of us out here. :cool:
     
  5. vibrations1951

    vibrations1951

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    Thanks so much Thomas. I checked the site and nothing yet but looks like a great resource! Greatly appreciate the connection. I hope I can hold out long enough although those prices on new units help, but as all of us find out sooner or later, nothin' cheap about this kind of project!!

    I want to do it right yet I don't I don't think a used transformer is a bad idea. Do you or any readers have an opinion here as my experience is limited??

    Wish me luck!
     
  6. MadMax

    MadMax

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    There's not really anything that can go wrong with a transformer... either is works, or it doesn't.
     
  7. djmukilteo

    djmukilteo

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  8. vibrations1951

    vibrations1951

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    Update. Turns out that a highly reccommended transformer type is Tiroidial. Power usage/loss is nearly nonexistant, can handle high power draw well beyond rating for a couple of minutes and usually comes with a shield I believe. I am going to attempt to post some info here. Thanks again for all the help. Hope this helps others.
    PS I'm going with a 10KVA unit, single phase, 60Hz to two legs (40A on each) on the studio 100A subpanel replacing the 100A main breaker with an 80A main breaker. The transformer will be fed by a 100A breaker off the single phase, 240v 200A 60Hz main entrance breaker box. My "dirty power gets the other 100A from a separate breaker box off the main.


    http://www.zycon.com/Products/Transformers.html?src=google&gclid=CLvEg9nLpJ0CFeRL5Qod4Vck2A

    http://www.equitech.com/products/industrial/xfmrs/toroid.html

    I actually am ordering mine made by Toroid.com--a guy named Ming Zu there was incredibly helpful and knowledgable about studio setups. I'll let you know how that works out. ciao, jp
     
  9. MadMax

    MadMax

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    Equitech makes some good stuff... I just couldn't afford it.

    That jump from 10KVA to 15KVA makes a world of difference in pricing!

    I just wanted to have the extra grunt available if I would ever find a nice 8088 or someone throwing their Legacy out.

    Good score!
     
  10. vibrations1951

    vibrations1951

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    Good to hear the confidence in Equitech. I plan to compare prices on their "'Q' type transformers" with the Toroid company now that I think I know what I need. I'm waiting for a quote from Toroid.

    I'm hoping to someday go with the Toft ATB32 in conjunction with my G5 with Nuendo (hope to do video work some day as well so Nuendo made sense). Not really sold on digital but trying to get the best of both worlds if you know what i mean.

    Soooooo....If I were ever to have the opportunity to snatch a nice 8088 or Legacy from say the dumpster I'll have to hock what I can to upgrade then!!!

    I'll have to see what the price jump from 10KVA to higher would do to my pocket book though right now, 10KVA might be all the stretch I can do. This is a long term project so at times it's easier to justify the expense but of course, there is so much gear I need and more I lust after! Yet, walls and ceilings would be a plus as well!!! I'll try and keep ya updated. Thanks for the info. ciao, jp
     
  11. vibrations1951

    vibrations1951

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    quick update. I checked Equitech and wow the prices. The quote Toroid gave me is much lower and makes me nervous...can it be right? 10KVA (secondary output 120V, 60hz, two legs and neutral with 40A rms ea leg and a static shield for ground). The whole rig with case is 155lbs. and cost is $1562.75. Equitech does have a few more bells and whistles but my god...4x's the cost or more???? Am I missing something here?? Sparky thinks it's all ok and i trust him though he has never done a recording studio before. He is very humble and honest. Any thoughts please! Thanks, jp
     
  12. MadMax

    MadMax

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    uh huh.... see my post before....

    Now you know why a traditional 15kva Square D is what I went with!

    Equitech (and all the toroidal mfr's for that matter) are sure proud of their gear... and charge accordingly.

    I just couldn't afford em'.

    If you look at the reality of toroidal vs conventional iron core iso, you can go up in KVA and essentially come out about the same AFA power soak.

    (Hoping Davedog or Rod will jump in and fix my statement if I'm too far off on the simplification)

    Lets say you come in needing a total energy transfer of 8KVA... which is a LOT of power... (8000/120=66amps) at continuous full load capacity.

    For a toroidal transformer, they can operate under 80% load all day and not bat an eye.

    For a conventional iron core isolation transformer, you should really only hit them at 50% continuous load. Otherwise, you can start to saturate that core and then noise CAN begin to play with the transfer of drops and spikes.

    Overall, the main advantage that I see with a toroidal is the size when you factor in EVERYTHING... cost, shipping, performance, etc.

    But when I could get a conventional 15KVA for 1/4 of the cost of a toroidal...
     
  13. Davedog

    Davedog Moderator

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    This is basically correct.

    Understand this about transformers. They will only do what you feed them with. You arent looking for anything that would be operating as a buck/boost but simply looking for quiet power, so a simple iron core rated at above your needs will do the trick and save you some cash.

    Again, understand that the ratings are all about potential. Demand creates the potential. If you are only using a certain number of watts at full load then that is what your current is going to drawing. Your demand will determine this. The ratings only give you the largest recommended current the transformer can safely operate at for an extended period of time. You have to view the current for a studio as a continuous load since by all thoughts the load is going to be on for a number of hours at a time.

    So if you fuse the primary of the transformer with 100 amp fuse(breaker) then the transformer, if it has a windings ratio one to one, will have the potential of 100 amps on the secondary.

    I guess my next question is what do you intend to run from this panel besides the rack gear and the recepts for instruments? Understand that ANYTHING that is one this panel can effect anything else on that panel as far as noise.So, an AC unit or any other motor load can potentially add noise to the line as well as sag at starting currents.

    Aint electricity fun...!
     
  14. vibrations1951

    vibrations1951

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    OK guys I may be starting to get this (or not :oops: ). I've been checking traditional isolation units right along as well and have not been able to get close to what i think I need on the used market. New on the traditional units in terms of apples for apples so to speak is about the same as my Toroid quote- about $1500 range or so. The traditional was a 15kva and the Toroid quote was for 120V,60hz, 80A (60+A output utilizing the 80% figure). The traditional 15kva (going with the 50% guidlines mentioned for traditional iron core) would be about the same 60+A.

    Rack gear-right now about 10A-which includes some tube units, hearback system, 2 Lynx 16's (plus computer, powered plug-ins). Then Toft atb32 console with meter bridge, 52"video screen, powered 5.1 for CR, powered nearfields, amp for foldback in live room, 2 tier digital Allen church organ with 4 power amps.

    That is not my present gear list but what is planned for right now. There is nothing around our area for audio or video post production for hundreds of miles (of course not many people either for that matter!) but there are very many music and top notch video folks (friends) looking forward to a facility and I will likely be serving the local new performing arts center being built in stages at the local high school. With all these possibilities I want to be prepared for whatever the future may bring so expansion is not out of the question by any means.

    My "dirty power" will all be on a separate 100A subpannel-HVAC, heating, lights, fridge, nuker, coffee pot, central vac.

    I guess I don't really need to rush. I could wire up my "clean pannel" before putting the iso-trans in line before it and try to wait for a good deal on a used traditional unit. I may have to but as it is, I have a couple of very talented young guys wanting to do more (I had to stop tracking because I was using bare bones #12 extension cords from the house to power things up and what a mess! I also do a lot of work for a guy doing lots of voice overs. Hate to turn them away but the new power feed may be adequate enough for now with star grounding.

    This could help some but the ledge becomes quite a problem around here for transmitting voltage through the ground and a retired neighbor 1/4 mi away loves to crank up his wood shop. Lots of farmers here need the iso transformers so the cows will produce adequately. Volts travel far in these parts, not to mention the high incidence of lightening strikes! The electrician had a tough time getting enough ground contact for my supply ground rods.

    I may need a line reactor later on as well. The power company has agreed (I hope) to put in a bigger transformer on the feed line to the house (I am the last on a very low voltage feed) because it is not uncommon to see 117volts as norm at the entrance to the house and drops down to 104v at the equipment while trying to do minimal tracking right now (maybe 8A draw at the most! Of course the extension cords don't help either!) I am anxious and you can probably see why.

    I am rambling but I sure do appreciate all the advice so please keep it coming before I do something I'll regret. ciao, jp
     
  15. MadMax

    MadMax

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    jp,

    Yeah man... Me thinks you're startin' to dial in on this.

    I'll try to keep an eye out for 15KVA's for ya'. Don't it figure... when I was desperate for one, I couldn't find em'. Then, after I got mine, I see em' quite regularly. DOH!

    Try EMSCO out of MN. They've been around for a pretty good while, and might be able to snag ya' one.

    Good luck and keep us updated!
     
  16. dvdhawk

    dvdhawk

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    Wow, that is some serious voltage drop. Have you looked into any of the line conditioning products that keep the voltage up - like Tripp-Lite or Furman?

    It would be a stop-gap measure to stablize the voltage, but I wouldn't want to run sensitive equipment at 104v either.

    http://www.tripplite.com/en/products/model.cfm?txtSeriesID=326&EID=13691&txtModelID=2832

    or

    http://www.furmansound.com/product.php?div=01&id=AR-20_II

    Hopefully the power company can get the voltage up to a respectable level with a new transformer. If not, you might have to think about going solar like one of the other posters here.
     
  17. Davedog

    Davedog Moderator

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    I'm not sure that these products are going to do much for an undervoltage situation. They will protect and regulate for over but not much in the pdf about under....

    Understanding more about your situations brings up a lot more thought . Undervoltage is a serious situation for electronic equipment, and having a situation where you are the last on the line in a rural area brings its own set of problems and ones that are not easily fixed.

    A line conditioning transformer will only do something for you if it has taps on its primary and even its secondary. This is how you would be able to get a transformer to 'boost' a voltage.

    Earlier I spoke of working in a buck/boost situation and indicated that you might not need that. I stand corrected. You very much need a transformer capable of putting out a higher voltage than its input. And I know you dont want to hear this, but this solution is going to take some cash.

    I run a variac on my console because the higher input voltage makes the rail voltage more constant and the pres are 'creamier' and more musical. And I'm not subjected to a full 'brown-out effect if theres a drain in the area.

    Those of you who would say, 'Hey! Dog, the rails are a regulated supply" would be right on one side, but not both. So I run my console at a constant 127 volts.....below the manufacturers upper range for this unit.

    Maybe you should look at something like this for the primary side of your transformer or look into a trans with taps.
     
  18. vibrations1951

    vibrations1951

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    Heh Max , that would be great! Now another ques. would power usage be 30% difference? If that is so, @ my cost for residential usage, $.12/KW, rough figuring, that would be around $400 more/yr electric bill for traditional unit as opposed to toroid.??Please set me straight. I'll check out EMSCO. tanx, ciao
     
  19. vibrations1951

    vibrations1951

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    Hello and thanks Dvdhawk and Davedog. I did check out the Furman stuff and others and came up with the same thoughts as Davedog. I have considered the buck boost and may need to go that way. The Variac is something I'll look into. I guess I'll have to wait until the power company sets me up and i get some actual readings under load to see how many more years I'll have to put in on my day gig! Line reactor may be needed as well...jeez louise!! Thanks guys, jp
     
  20. vibrations1951

    vibrations1951

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    Oh No. Info. overload here. The transformer primary will be fed with 240v 100A, 60Hz single phase. If I have 2-120v 40A RMS lines plus neutral coming off the transformer secondary fed respectively to the 2 bars and neutral of the subpanel, could this create a phase and resulting noise problem when I balance my loads from the subpanel, tapping circuits from both sides of the panel to utilize the potential 80A from that panel, (120V, 40A on each bar/leg of the subpanel)?? Does it matter Toroidal/Traditional as well??
    Am I over thinking things here?? lectricity..can't live with it...can't live without it!
     

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