Re: Variac Help

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Esondrmn-at-aol-dot-com 

In a message dated 11/20/03 6:45:36 AM Pacific Standard Time, 
tesla-at-pupman-dot-com writes:


>I am in need of help on wiring of a Technipower 30A Variac.  I purchased it
>used and there are no instructions. I don't want to toast it as it was a
>little on the expensive side so your assistance is appreciated.  It has
>five connection points in this order;
>
>1  5  3  2  4
>
>1 = one end of the coil
>5 = between connection 1 and the center tap
>3 = center point of coil
>2 = between the center point and the end of the coil, point 5
>5 = the other end of the coil
>
>This is a 130 volt single phase model that mounts inside a cabinet of some
>type and does not have it's own enclosure.. My question is which points
>does the 120V supply connect to and which points are the output. Also where
>would the safety ground connect.
>
>Thanks in advance for your help,
>
>Emmett


Emmett,

You don't mention the connection to the wiper (brush) which will be one 
output.  We normally would use this variac by connecting the 120 volt ac 
input power to the most outside terminals which would be 1 and 5.  Then, 
assuming the wiper is contacting terminal # 1 when in the off (fully 
counter clockwise position) the outputs would be from terminal # 1 and the 
wiper (brush) contact.  This should produce 120 volts out.  If you connect 
the ac input voltage across terminals # 1 and the second terminal in from 
the other side, you will have 130 to 140 volts out.  I always connect the 
metal frame of the variac to line ground - green wire.

Ed Sonderman