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Isolation Transformer and Subpanel recommendations

There are many isolation transformers out there new and used. What are the best recommended 5kVA/other isolation transformers for high-end audio setups. I live in the US so I need one that would be configurable for 110/120V output. I intend to put this on my dedicated circuit after my main panel in the house. The dedicated circuit is high-quality and 20-amp/10-guage in nature; this circuit is 110/120V, not 220. I'm looking for any recommendations for units that run quiet and have high common-mode noise rejection.

Also looking for recommendations on good quality sub-panels.

Thank you in advance for the assistance!
zephyr24069

Showing 3 responses by ngjockey

ngjockey
1,042 posts
 
Noise is unpredictable for either type, aggrevated by external conditions. Potential advantage of tighter windings of toroidal is offset by greater sensitivity to same conditions. Some people mount the transformer near the electrical panel (basement?), away from the living space.

Dryers and ovens are usually 240V.
ngjockey
1,042 posts
 
Quick search on Ebay turned up empty for this size and 120V. Generally prefer iron core instead of wide-band toroidal for this purpose. If it's going to be close to the rest of the system, toroidal has the benefits of less stray EM and more convenient packaging. Without step-down....

http://www.surplussales.com/transformers/IsolationXmers-3.html

Although, if you can get 240V there, options get much wider and less expensive. Perhaps even the option of center-tapping, if derated by half.
ngjockey
1,042 posts
 
For 240V, as an example...

http://www.ebay.ca/itm/FPE-5-KVA-1-Phase-240X480V-120-240-Volt-3R-SE2N5FS-Transformer-NEW-/310425276037?pt=BI_Circuit_Breakers_Transformers&hash=item4846c9ce85

Sola/ Hevi-Duty and Acme are usually the best bets for sheilded like this one. (the dashed line in the schematic)
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