I have a facility control with Tracer Summit and would like to install power monitoring and controls to shed loads when the power exceeds a preset limit. The purpose is to reduce peak 15 minute demand from approx. mid May to July for a smaller utility bill the other 9 months of the year. Last year we hit a peak of 477kw in May some time last year, but the following 3 months we never exceeded 318 kw. That extra 100kw cost us approx. $10k in higher demand pricies for the remainder of the year.
Here's the HVAC equipment I can control trouch Tracer Summit:
3 Voyager RTU with gas heat and economizers (no sure on size, I think 10 tons each)
1 Voyager RTU with electric heat, economizer Varitrac II system (again 10 tons)
Chilled water system:
New Trane CGAM 130Ton just installed (4x20 ton and 2x25 ton compressors)
1 large custom air handler with economizer supply & return fans. (estimate 50 ton capacity, using only 2/3rds capacity on current building design (1 wing left unfinished). VFD on chiller water pump to control discharge temp. Hot water reheat from a steam heat exchanger.
1 10 ton air handler with 2 pipe hydronic coil. Trol-a-temp - zone control sytem. VFD on blower.
Couple dozen 2 pipe hydronic fan coils - not on tracer, other than the stema heat exchanger.
The load on chilled water system at outdoor design conditions I estimate currently is only about 80 tons, but it will run at max for almost 10 minutes when changing over from heating to cooling mode as warm water hits the system. Heat supplied by gas fired steam boilers.
My thought was to monitor current on the incomming power. If it exceeds lets say 450 amps, then the control starts restricting the RTU's to 1st stage, and either limits RLA, disables the 3rd compressor in each circuit or raises the chilled water setpoint.
How hard is this to do? Has anyone done this before and what were the results?