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So the power company upgraded me to a 50 KVA transformer after the 25 KVA exploded. I am running 200 amps at 120v constant. Anyone know if this is safe on that size transformer? I dont want to blow another one, they will charge me a ton of money.

I don't know what would be "safe", but...

120V X 200A = 24000VA

How long have you been running the 25 KvA one?
If you have been running it for a long time, then there shouldn't be much risk.
But if it happened the first time you used, then you might want to do the power calculation.

I am guessing the fluctuations with that would cause you to blow your transformer.
@allcoinminer, how did you come to 24KVA , with 200A and 120V?

Sorry for the noob question but do we have transformer outside of every house? I can't find mine..

I don't think so.. Transformer for us here is for several houses not every house..

I think you mean 200Ax240V if your in the USA.

Most houses have 2 phases of 120V at 200A to max your circuit you would have to use both phases that are 180 degrees off from each other.

To anwser your question to be safe you should use up to 80% of your max load continously.  So for like mining you should be using 160A per phase, if you have all your miners only on one phase of your house try wiring your circuits for 240v to balance the load.  Or manually move some of your miners to the other leg so one side of your circuit is not maxed.

I am currently upgrading from 200A to 400A and their installing new poles, transformers, meters, etc etc.

Depends on the power build out design.  My house shares a transformer with 3 houses; I have also seen a large transformer power one whole side of a street of houses.

Its used for long distances to convert low voltages(and high currents) to high volatges(low currents) and viceversa.
In a local area, all houses are close, so a transformer usually exist at a local area, and from there power is sent to the houses.
But some houses, or a group of houses have their own as well.

I dont want to repost everything in here, I see you did a very good job with this thread, so could you guys take a look at this thread and let me know what you think

https://bitcointalk.org/index.php?topic=882414.0

are you mining at home because all you get is 200 amps at 120v. that's the max unless your in a facility.

You actually blew a transformer. wow.
 
How much do you pay for electricity in a month?

Distribution transformer usually had protection like circuit breaker or fuse. The one near my neighborhood use NT fuse.
So even if there is any overload, the fuse will be burn not the transformer(happen every week  :D).

If the transformer is exploded, it's just weird. Either the transformer already too old or the power company forget to change the insulating oil.

I would say this too. There is always a circuit breaker or a safety mechanism in it, because the companies can't just take a loss of thousands of dollars if an overload happens.
You can also ask the company why the transformer exploded in the first place.

50Kva at 120v is 416amps..

so you have two hot legs.. your running 200amps so 100 on each leg as long as they are distributed evenly leaves you 3/4 load left over.(too the transformer). but if your sharing it with other houses thats not much.

The real question is what is your main breaker, and go buy a clamping amp meter, even your load over your two single phase legs and stay under 80% of your main breaker and you'll be fine.

Let me know if you need more info.

Thanks

Chicagoleo
========================
http://coin-mining.mystarpoint.com

I have had a similar issue as well, but turned out some kind of breaker circuit saved it. THats what the guy who came over to fix it said.
I wasn't sure it was due to mining, but definitely looked like it.

Mine has one of the big ceramic fuses on it.  When I was looking at it closely one day I noticed that the fuse had been bypassed.  I'm not sure why.

Yes, that is nt fuse. The fuse must be already burn then the engineer make "emergency" repair  ::)
The fuse is expensive  :D
This may cause problem later since there is no protection if something happen like overload, short circuit, unbalanced load etc

Because of the sine form of mains power this 120 V is only the RMS voltage. According to Ohm's law current and voltage are proportional. Constant 200 A gives then sqrt(2) at peak resulting 283 A. But voltage isn't always the same. If the highest value is 6 % over the normal then it would result 300 A peak. The needed capacity is then 36 KVA. 50 KVA should be fine.

^^^ or for everyone else...  Don't go over 80% , lol

I believe it also depends on the temperature on the outside, if it is summer, I think only 70% load is safe as it is really hot.

anyone ever try this?
 https://www.youtube.com/watch?v=Vcbw-t-CCx4