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FindRootSimpleController

asked 2024-03-12 08:03:58 -0500

Yagnik's avatar

updated 2024-03-14 15:25:41 -0500

hello,

I am encountering the error like * Severe * FindRootSimpleController: Controller error for controller = "CENTRAL COOLING COIL CONTOLLER 1". I have tried to find solution but I could not by my self yet. and here is the error message

************* Beginning Simulation
** Severe ** FindRootSimpleController: Controller error for controller = "CENTRAL COOLING COIL CONTOLLER 1"
** ~~~ ** Environment=WEATHERFILEDAYS, at Simulation time=01/01 20:03 - 20:07
** ~~~ ** Controller function is inconsistent with user specified controller action = Reverse action
** ~~~ ** Actuator will be set to maximum action
** ~~~ ** Controller control type=Temperature and humidity ratio
** ~~~ ** Controller temperature setpoint = 6.31E-003 [C]
** ~~~ ** Controller sensed temperature = 7.62E-003 [C]
** ~~~ ** Controller humidity ratio setpoint = 6.31E-003 [kgWater/kgDryAir]
** ~~~ ** Controller sensed humidity ratio = 7.62E-003 [kgWater/kgDryAir]
** ~~~ ** Controller actuator mass flow rate set to 4.07 [kg/s]

************* ** Severe ** FindRootSimpleController: Previous controller action error continues for controller = CENTRAL COOLING COIL CONTOLLER 1
************* ** ~~~ ** This error occurred 575 total times;
************* ** ~~~ ** during Warmup 0 times;
************* ** ~~~ ** during Sizing 0 times.

I have checked all the avilable question at unmethours and repo:NREL/EnergyPlus in github, but I could not get satisfied answer to it, so could you please make this clear for me.

Thanks in advance... Yagnik

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answered 2024-03-12 08:14:46 -0500

updated 2024-03-14 10:28:55 -0500

It appears from the warning message that you have set the temperature set point to a humidity ratio instead of a temperature. Check which type of set point manager is used for temperature control.

Update: when using water coil controller control type = Temperature and humidity ratio, the controller may switch to humidity control where the humidity ratio is the active set point. This is normal and the message is being clarified in the E+ engine software.

Controller temperature setpoint    = 6.31E-003 [C]
Controller humidity ratio setpoint = 6.31E-003 [kgWater/kgDryAir]

Regarding this type of water coil controller error message, if the water cooling coil outlet air set point temperature is lower than the chilled water temperature then the controller will throw this message.

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Hello, Thanks for responce, I have used in class list - 'Controller:WaterCoil' Temperature and humidity ratio.

here is the field of class list - 'Controller:WaterCoil' IDF,Controller:WaterCoil, name - Central Cooling Coil Contoller 1, control variable -TemperatureAndHumidityRatio, Action - Reverse,Flow, Actuator variable - Main Cooling Coil 1 Outlet Node, Actuator node name - Main Cooling Coil 1 Water Inlet Node, Control converegence tolerance - autosize, maximum actuated flow - autosize, Minimum actuated flow - 0.

I have reffered to the examlpe file - 5ZoneWaterCooled_GasFiredSteamHumifer

Yagnik's avatar Yagnik  ( 2024-03-12 09:01:51 -0500 )edit

Yes, that is your water coil controller. But you also need SetpointManager* objects to place a temperature set point and humidity ratio set point at the air outlet node of the coil (Main Cooling Coil 1 Outlet Node). Which set point mangers are you using for temperature and humidity set points at this node?

rraustad's avatar rraustad  ( 2024-03-12 09:44:47 -0500 )edit

Hello, I have used Setpointmanager:MultiZoneHumidity:Maximum and MInimum for the humidity control and SetPointManager:Scheduled with control variable temperature for the temperature control.

Yagnik's avatar Yagnik  ( 2024-03-12 10:54:52 -0500 )edit

Can you paste in the SetPointManager:Scheduled object used for this cooling coil? Or add it to your question above.

rraustad's avatar rraustad  ( 2024-03-12 11:06:25 -0500 )edit

Yes, sure IDF,SetpointManager:Scheduled, Chilled Water Loop Setpoint Manager, Temperature, CW Loop Temp Schedule, Chilled Water Loop Setpoint Node List; and

IDF,Schedule:Compact, CW Loop Temp Schedule, Temperature, Through: 12/31, For: Alldays, Until: 24:00, 5.7 let me know if is still unclear

Yagnik's avatar Yagnik  ( 2024-03-12 11:12:32 -0500 )edit

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Asked: 2024-03-12 08:03:58 -0500

Seen: 158 times

Last updated: Mar 14