[Boatanchors] Big, old & heavy transformer ID
Barrie Smith
barrie at centric.net
Sun Jan 31 19:18:24 EST 2010
Hello:
I have a large, heavy transformer I'm trying to figure out. It's 13" X 9" X
9" and certainly weights over 100 lbs.
It does have a rather difficult to read label on it. The manufacturer is
"Ameritran". The model number is 31029. The KVA test is 7.5. Primary is 220
volts and secondary is 1500/3000 volts. The rated KVA is 2.1.
While I'm pretty sure the secondary is not center-tapped, it does have three
terminals. One is much larger than the other two. I'm guessing that the
larger one is one end of the winding, the center one is 1500 volts and the
third is 3000 volts.
The primary also has three terminals, and that's where I'm lost.
Using a 120 volt (not 220) variac earlier today, I measured (using the outer
terminals, which I would think correspond to full primary and full
secondary), 1100 volts, or 2200 volts if I were using 220 on the primary.
If I put the primary voltage to the leftmost terminal (which I would think
would be number 1), and terminal number two I got, with the variac only half
way up, 3600 volts! Looks as if I was using only a small portion of the
primary and the turns ratio was very high.
If I put the 120 primary voltage to terminals number 2 & 3 I got 1600 volts,
which sounds about right for 220 in and 3000 out.
My confussion is regarding the primary terminals. It looks as if terminal
number three is common, and number two is the tap? Usually, with tapped
windings, terminal number 1 is on the left.
I've done a lot of Googling on this manufacturer and have come up short.
If anyone has any information on this transformer, or ideas on the primary,
I'd sure appreciate it.
73, Barrie, W7ALW
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