User-agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0
Vincent,
What is the rating of the fuses you are using? 10 amps?
Are they slow blow or fast blow fuses?
Many old-school name brand variable autotransformers (Variac, Powerstat)
can handle double their rated nameplate current ratings for short runs
of 30 - 60 seconds without being damaged. Can't say the same for some
of the cheap Asian imports, though.
A Variac is not the part of the circuit that provides current limiting.
That is established by the NSTs themselves.
If you want to run 4 NSTs simultaneously, you will need a Variac big
enough to provide the all current they require.
Adding power factor correction capacitors (PFC) to the transformer input
may help manage their current drain.
Dave
On 11/24/2015 7:46 PM, Vincent D'Amore wrote:
Hi All
Recently I've been running my coil controlled by a 10amp variac. I'm running two parallels 12/30 franceformer neons sign transformers and have been running this way for several years but as of late I keep blowing fuses on the variac about every 4th run. I'm not sure if or what has weakened over time. I would like to run my coil with a much larger power supply but that obviously won't go over well with my 10amp variac and I certainly don't want to move forward until I know the weakest point. Any suggestions? Also if I do go with a larger supply I'm thinking of 4 12/30's in parallel but don't know what to do for current limiting. Larger variac? Something else? Thanks for any advice.
Vincent