Chiller or boiler seasonal lockout

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I thought I had a correct example, but it appears the chiller I have is not shutting off during the winter season. What am i doing wrong (I can apply this also to boiler).
Thanks. It has been a long day.
John R. Aulbach, PE

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I wasn?t able to achieve the seasonal control. I am not sure what the correct steps are. It seems like it should be fairly simple ? one flag for LOOP-ON and another flag for LOOP-OFF but it doesn?t seem to work.

Christopher Jones, P. Eng.
Rowan Williams Davies & Irwin Inc.
Consulting Engineers & Scientists
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I would just use LOOP-OPERATION -> SCHEDULED for the CHW loop instead of bothering with the equipment control and load management.

William Bishop, PE, BEMP, BEAP, CEM, LEED AP | Pathfinder Engineers & Architects LLP
Senior Energy Engineer

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LOOP-OPERATION ? SNAP to an outdoor temp of 55-65 is my go-to quick means of approximating a seasonal heating/cooling plant lockout (and an appropriate starting point or guess when you don?t/can?t know an exact schedule for manual shutoff).

As Bill says, you can go further and assign a specific schedule under LOOP-OPERATION using an ON/OFF/TEMP. Natural progression when you have calendar dates in mind for the lockout and/or you have a combination of snap behavior and forcing things off to consider.

If you need to lock out SPECIFIC boilers/chillers, then you gotta step up to equip-controls/load-management. Eliminate the simpler options before pressing forward.


Nick Caton, P.E.

Senior Energy Engineer
Energy and Sustainability Services
North America Operations
Schneider Electric

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