3-Phase Dual Transformer

Three-Phase
three_phase_11000-voltThis diagram is taken from Electrical West, Volume 33 pub.1914.

I used this diagram as a guide for my own version. I liked the complexity but I wanted MORE .. so I added a workers platform. I am mostly concerned with how it looks .. not so much on how realistic .. although in this case it IS based on the diagram.

2trans3phsseHere we go .. side bracket transformer of the left. I will be using two of these side by side and wired as in the diagram.

Some of the photos I have found of older can type transformers were ribbed to aid cooling .. so I did that with these. The side/bracket mount was just to add intrest.

doubleworking.. and .. here we go. I followed the diagram pretty much but added a platform, ladder and foot pegs.

I also added telephone/telegraph insulators down lower .. again .. to add interest. Hey .. if you can’t have fun why do it.

2trans3phaseWiringHave all the wiring figured out except for the ground. In the wiring diagram above it shows the center lug grounded. Nothing is shown connected to the right center lug. I can *assume* that this is also grounded but .. gonna ask the experts
Notes
Cross-arms for telephone lines are usually 10 or 6 pin, the wires adjacent to the pole being 16 inches apart and others 12 inches apart. Cross-arms are mounted two feet apart. Poles are usually set to give an average span of 130 feet.1

On 40 ft. poles the transformer arms are placed 4 ft. below the 11,000 volts arm; on 45 ft. poles, 7ft; and on 50 ft. poles, 10 ft.2


  1. Electrical Engineer’s Pocket-book: A Hand-book of Useful data for Electricians and Electrical Engineers. pub. 1908 []
  2. Electrical West, Volume 33 pub. 1914 []