[time-nuts] Three Phase Power

Jason Rabel jason at extremeoverclocking.com
Mon Jun 27 20:38:01 UTC 2011

Will & Bill,

Our (commercial) three phase power is fed by only two high-voltage wires (7,200v I think) which each pole has a pair of
transformers. I can only assume one generates the 220v single phase lines and the other is the high-leg delta. Around here 230v
three phase delta seems to be more common than 208v Y style.

I remember a couple years ago we had a transformer die (thankfully it was a passive failure and not a massive fireball on the pole).
People were wondering why their machines weren't working (but the lights were on)... Sure enough hooking up a meter and the high leg
was dead...

I did read somewhere that this change might have an effect on demand meters? There was no further explanation unfortunately, but
that does kind of worry me as I know about 90% of the meters on our property are that style. The power company just loves to tack on
a "demand charge" to the bill, which can often double, or triple the cost of your electric... Just because you want to have the
lights on, A/C running, and an air-compressor... :(

I've never seen or heard of anyone here in Houston with three phase residential (except for farmers, but I guess they are

Centerpoint Energy has reached the epitome of laziness and is converting everyone over to "smart meters" so people can better
monitor their usage... In reality it does nothing more than offer real-time monitoring for the power company, and they no longer
have a use for meter-readers...

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