My Variac setup keeps tripping the breaker.

I am building a tesla coil and was testing out the Neon transformers in the garage, but when I powered on my variac the indicator light didn't turn on. I then switched to another outlet.. the same. I didn't even have the variac on and I checked for shorts, but couldn't find anything. I guess I blew the breaker to the garage because I ran an extension cord from an inside outlet and it worked.
Any suggestions on why this might be a problem or how I can include an inductor or something to slowly build up the current so it's not constantly going off?

Not enough details...
What voltage rating is the Variac. What is the wll AC voltage? Is the variac wired by you, or does it have a "standard" plug? How is the output wired?
Any mis-wiring will cause a breaker to trip....

sagor1 said:

Not enough details...
What voltage rating is the Variac. What is the wll AC voltage? Is the variac wired by you, or does it have a "standard" plug? How is the output wired?
Any mis-wiring will cause a breaker to trip....

Click to expand...

It is a 2000 volt 20 amp fuse variac. The wall input is 120 vac, The cord from the wall to the variac is the cord that is attached to the variac. I have a heavey duty cord from an old microwave oven about 3 ft long grd, hot, and neutral. I connected the grd to grd on NST, the hot and neutral to the ac inputs on the NST. Another piece of information is after reseting the breaker the variac was working.

Ok, as long as it is wired right, you should be ok.

If you had a full load when you first turned it on,it is possible the circuit had other loads and tripped the breaker