Bitcoin Forum

My poco is saying I will need a THD filter on the secondary side because other bitcoin miners have burnt wiring or transformers.  They say I will, of course, have to pay for it.

Has anyone heard of anything like this?  I know THD is "bad", but can it really hurt a transformer?  I'm assuming they are really talking about a poor power factor, which can overload a transformer prematurely and also cause THD?

Anyway, just trying to get 800A service put into my house.  They are being surprisingly supportive aside from this stupid filter. :)

THD can cause transformers to heat up but you would need a very high transformer load to even being to worry about it.

First off, the PSU is the one that would be creating the harmonics, not the miner itself.

Second, with proper wiring and breakers nothing will heat up or burn.

I realize it is the power supply causing it, which is why I intend to measure the THD on my EVGA power supplies to see how good or bad they are.  I imagine that they would be better than the aliexpress "bitcoin" power supplies?  Maybe even bitmain supplies are junk?

In the small time I've looked at "filters" (so far the poco has not got back to me on what exactly they are proposing I buy) I could just buy EVGA Platinum-Titanium supplies exclusively rather than the filter!

Where I am it is not uncommon for a 15kva tank to supply 3-4 homes or 25kva for 6 homes.  They know my load factor will be a max of 150kva and it is possible that I will be the only home serviced by that transformer.  They are just afraid because before they discovered someone mining burning up their undersized transformers (based on typical residential loads) and in some cases burning up utility side secondary wiring...

Would THD transfer to the primary side of a large 150-200kva transformer?

How much are they wanting to charge?

For the service?  They are working up an estimate.  Hopefully I won't owe anything after all of the new service credits (50% up front, 50% after one year...$100/kw).  I have to pay for the labor, ditching, wire, CT enclosure, and meter can and everything else on the customer side.  I'm hoping they will accept 4 200A fusible disconnects and 4 200A 3R panels with 4 50A outlets on each.  After I get the jigawatt dealer on my side then I have to convert the code man.

I have an electrician friend who will pull the permit and I'll probably do some of the labor.  All in I expect to pay $5-10k materials and labor.

Gotcha, thank you for the breakdown. I just meant the THD filter :)

The distribution engineer told me the design engineer would require it, and that I should ask my engineer what it would cost.   >:( >:( >:(

If they are requiring me to have a filter that isn't specifically required in code then they should be able to provide me an example of what I would need to buy.  I'm not interested in paying an engineer to bounce proposals back and forth to see what sticks.

Because of the service size I will need to hire an engineer with a stamp to write down on a piece of paper the number of circuits and miners on each circuit.  Load factor, power factor, etc.  My electrician has one that will help on the simple job, but I told the poco I didn't want to waste any money until everything was basically approved and the costs known.

Like I said, the distribution engineer has been very helpful.  After explaining the situation to him, like the economics of mining with .1415/kw electricity, he is agreeing to basically jump forward and price the system and follow up with the engineering later.  I should hear back about the filter Monday or Tuesday next week.  I am going to see if the power factor is good enough on the power supplies that they will forget about the filter.