Water Cooled Chiller CheckForRunawayPlantTemps Fatal Error

Hello All,

I am trying to model an air-cooled chiller plant vs. a water cooled chiller plant in Open Studio to present two different options for a client. The air-cooled chiller plant worked flawlessly. The water cooled plant keeps generating a "CheckForRunawayPlantTemps" fatal error. I have checked the following:

1) Setpoint manager for condenser water plant: set to 85 degrees (F) year round. 2) Changed constant speed condenser pump to variable speed pump. No change. 3) Made sure to add chiller and condenser water bypass pipes. No change. 4) Pumps cycled from intermittent to continuous duty. No change.

Any help is greatly appreciated.

AlwaysFrosy's avatar
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AlwaysFrosy
asked 2018-04-19 09:38:17 -0500
__AmirRoth__'s avatar
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__AmirRoth__
updated 2018-04-19 10:08:43 -0500
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Which loop is giving you the error? You are on the right track to check pump operation - this usually happens because the pump is running without any heat exchange on the loop. Try setting your pumps back to intermittent, and check the flow rates on the pump to see if it is operating when you expect it and then report back.

mdahlhausen's avatar mdahlhausen (2018-04-19 15:53:45 -0500) edit

The condenser water loop was giving me the error. The cooling tower defaulted to an 85 degree leaving temperature as well as a 20 degree Delta T. When I changed the delta T to 10 degrees, the error went away. I'm not sure why but it seems to be working now.

AlwaysFrosy's avatar AlwaysFrosy (2018-04-20 08:00:51 -0500) edit
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