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3242 Severe errors - Controller error for controller=cooling water coil

asked 2016-05-18 16:26:41 -0500

rkbest gravatar image

updated 2017-05-17 12:23:16 -0500

I am unable to tweak this error which I got while running for full year simulation. I have set one chiller feed to TES and TES to the Colling coil in the secondary Chilled water loop. I have set the Controller for water coil as

IDF,Controller:WaterCoil,Controller Water Coil 2,Temperature,Reverse,Flow,CC Air Outlet Node1,CC1 Water Inlet Node,Autosize,Autosize,0;

The error I am getting is

 ** Severe  ** FindRootSimpleController: Controller error for controller = "CONTROLLER WATER COIL 2"
   **   ~~~   **  Environment=RUN PERIOD 1, at Simulation time=01/28 06:02 - 06:04
   **   ~~~   **   Controller function is inconsistent with user specified controller action = Reverse action
   **   ~~~   **   Actuator will be set to maximum action
   **   ~~~   ** Controller control type=Temperature
   **   ~~~   ** Controller temperature setpoint = 15.82 [C]
   **   ~~~   ** Controller sensed temperature = 16.13 [C]
   **   ~~~   ** Controller actuator mass flow rate set to 3.09 [kg/s]
   **   ~~~   ** Controller actuator temperature = 16.13 [C]
   **   ~~~   **   Note: Chilled water coils should be reverse action and the entering chilled
   **   ~~~   **         water temperature (controller actuator temperature) should be below the setpoint temperature
   **   ~~~   **   Note: Hot water coils should be normal action and the entering hot
   **   ~~~   **         water temperature (controller actuator temperature) should be above the setpoint temperature
 ************* ===== Recurring Error Summary =====
   ************* The following recurring error messages occurred.
   *************
   *************  ** Severe  ** FindRootSimpleController: Previous controller action error continues for controller = CONTROLLER WATER COIL 2
   *************  **   ~~~   **   This error occurred 3242 total times;
   *************  **   ~~~   **   during Warmup 0 times;
   *************  **   ~~~   **   during Sizing 0 times.
   *************
   *************  ** Warning ** SimHVAC: Exceeding Maximum iterations for all HVAC loops, during RUN PERIOD 1 continues
   *************  **   ~~~   **   This error occurred 40 total times;
   *************  **   ~~~   **   during Warmup 0 times;
   *************  **   ~~~   **   during Sizing 0 times.

While I am still trying to understand the SimHVAC iteration fix based on the suggestions here https://unmethours.com/question/17449...

Blockquote

IDF file -http://pastebin.com/MV1ET0dS

Blockquote

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answered 2016-05-19 10:44:47 -0500

rkbest gravatar image

My 'Sec-CW Loop supply Temp is schedule' for 7.5 C, Which is from TES tank with setpoint Temp of 7.5 C as well. I removed the Minimum Actuated Flow or 0 to nil Reduced ThermalStorage:ChilledWAter:Stratified: Deadband Temp Diff from 3.5 ->2.5 ( i think this did not help in anyway but I did not try to see the impact)

Added Cooling coil inlet & outlet node names to SetpointManager:MixedAir, Cooling Coil ( this was blank earlier)

This removed the warning

Now back to figuring the SImHVAC error that I am getting around 35 times with weather file simulation days.

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answered 2016-05-19 08:52:46 -0500

Your Controller Water Coil 2 applies to a cooling coil and is correctly set to be Reverse Action, so that's not the problem.

The problem is :

**   ~~~   ** Controller temperature setpoint = 15.82 [C]
**   ~~~   ** Controller sensed temperature = 16.13 [C]

Your loop temperature is higher than the setpoint, that's what you should investigate.

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Asked: 2016-05-18 16:26:41 -0500

Seen: 899 times

Last updated: May 19 '16