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Wiring an Isolation Transformer

I found a pristine, never been used, Topaz (Square D Company) 91018-31 1.8 KVA Ultra Isolator Line Noise Suppressor for $40. Other markings include .0005pF, 50/60 Hz, 120/240, Indoor Type 1, Enclosure Class 1-80 Insulation. However, it has no receptacle or chord.

My first question to the forum, is how to wire it? Could I just take a short extension cord, cut in half, wire the male end to the output side and the female end to the input side? Should I use bare wire under the screw terminals, or should I crimp/solder on spades? What wires go on what screw terminals? Some suggest balanced is the way to go. But some suggest this cuts the power in half, some suggest it doesn’t. Here is an example I found of balanced wiring:

Input:
Neutral (white) to H1
Hot (black) to H4
Ground to chassis

Output:
Hot 1 (white) to X1
Hot 2 (black) to X4
X2/X3 center tap connected to chassis ground and outlet ground.

Is this all there is to it? I am a complete newb when it comes to electrical work. Is this something I can do myself, or should I hire an electrician? Any assistance would be greatly appreciated.
cpalcott
cpalcott OP
14 posts
 
Ok, I heard fromn the electrician. I now undertstand the open ground reading was expected behavior. My only remaining question is, how many watts can I safely put on a 1.8 KVA iso transformer? I had it wired for balanced, so I am assuming that knocks the rating down to .9 KVA which would equal 900 va/watts, correct. Cut that in half to allow sufficient headroom would equal 450va/watts to work with. Is my math correct?
ngjockey
1,042 posts
 
Math is correct. 80% would be 720W.

Apple TV - reports from 20 to 48W
DIP - negligible 6W

Vide switcher/Tivo ???
My HD tuner/PVR is rated for 4A max (480W) and it can get warm.

Pre/DAC ???
examples: Plinius M8 - 20W, ARC LS17 - 50W, SFL2 -135W

Putting everything on a single isolation xformer defeats some of the purpose, don't you think? Particularly if you're mixing digital with analog or SMPS with linear power supplies.

How is the xformer for noise and heat? Shouldn't be uncomfortable keep your hand on.
cpalcott OP
14 posts
 
Thanks for the reply Ngjockey,

TADAC Tube Pre/DAC = 25W According to Paul at TAD)
Apple TV = 20W (according to Apple)
DIP (Original) = 10W (according to back panel)
Tivo HD = 40W (according to tivocommunity)
Video Switcher = (don't know but could it be much?)
TV = 240W (according to manual)
McCormack DNA-1 Deluxe = 400 (according to SmCAudio)
TOTAL = 735W (certainly pushing it depending on the draw of the switcher)

I don't have all this on the xfrmr right now. Just the PRe/DAC, Apple TV, DIP, Video Switcher and Tivo. In your opinion, what would be the most beneficial strategy for using the iso? I guess I just threw everything on there that I thought it could take. Anyway, it is buzzing but I can only hear it when I put my head right up to it. Can'thear it from listening position at all. Just barely warm after running it all night. I have to admit, I was skeptical about how much difference this would make. But it is significant. Not night and day, but very noticeable. The only way I can describe is that everything is just so much more right sounding. Whatever that means.
ngjockey
1,042 posts
 
Don't see any advantage of the xformer for the video switcher, which is essentially just relays. Wouldn't even try the amp on it, as much for the way it draws (half cycle cap recharging), combined with the capacity. TV is a noise source and one of the things to isolate from. Aside from that, glad it works and happy for you.

Now, you just have to try every brand of power conditioner to it and tell us how they compare.

Would've liked to see the electrician's expression when you mentioned balanced AC.
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