Working on a manufacturing facility audit here in Springfield served by City Utilities. They have a 150-ton chiller that cycles on and off throughout the day. Question - does anyone know if City Utilities uses 15-minute or 30-minute demand intervals? The billing doesn't specify and it's making a huge difference in how I calculate the potential savings from a demand limiting system.
Quick Question - Demand Reset Times
Elmer, most Missouri utilities use 15-minute intervals but City Utilities might be different since they're municipal. You should call their commercial rates department directly. Here in Corpus Christi with AEP Texas we use 15-minute windows and it makes a big difference for cycling equipment like chillers. A 30-minute window would be much more forgiving for demand spikes.
I believe City Utilities uses 15-minute demand intervals like most utilities. We deal with Alabama Power here and they're 15-minute windows on all commercial accounts over 50kW. The key thing with cycling chillers is that startup current - even with a soft starter you're looking at 2-3 times normal running current for the first few minutes. That can set your peak even with good load management.