Power Monitoring Tips

Consider logging your data in UTC more than local time. Daylight saving time switches will make your logging unhappy (parseecmpower will handle most artificial data jumps when time jumps back 1H and eventually data from 2:00 to 2:01 jumps by 1 hour's worth).
When you wire multiple CTs to the same input (like multiple breakers for lights), make sure to orient each CT donut according to the phase so that you don't end up having lights on one phase canceling out induced current from lights on another phase.
Setup monitoring to see when things go wrong. I had a mysql upgrade which contained a moronic change which moved logging to /var/run/mysql (thank you whoever did that) which will fill up /var/run tmpfs, cause mysql to crash, and cacti logging to stop.

Consider logging your data in UTC more than local time. Daylight saving time switches will make your logging unhappy (parseecmpower will handle most artificial data jumps when time jumps back 1H and eventually data from 2:00 to 2:01 jumps by 1 hour's worth).