TEC Controller Heating & Cooling Heat Pump with Internal Reversing Valve & Mixed Air Control, Application 2072 Application Note 140-1042 2014-05-01 Building Technologies
Table of Contents Overview ............................................................................................................................. 4 Hardware Inputs .................................................................................................................. 5 Hardware Outputs ................................................................................................................ 5 Ordering Notes .............................................................................
Overview Hardware Inputs Overview In Application 2072, the controller controls a heating compressor for heating and a cooling compressor for cooling. The reversing valve is controlled internally by the heat pump. In addition to compressors, this heat pump may also be equipped with electric heat for auxiliary heat, mixed air control for free cooling, and ventilation air. This application also controls small air handling units with two position heating and cooling control. Application 2072 Control Diagram.
Overview Hardware Inputs NOTES: 1. See Fan Operation. 2. See Control Temperature Setpoints. 3. See Heating/Cooling Switchover. 4. See Mixed Air Control. Application 2072 Control Schedule for Mixed Air Control. Hardware Inputs Analog Mixed air temperature sensor (optional) Room temperature sensor Room temperature setpoint dial (optional) Digital Night mode override (optional) Wall switch (optional) Hardware Outputs Analog None 5 Siemens Industry, Inc.
Overview Ordering Notes Digital Outdoor Air (OA) damper actuator (floating control) (optional) Fan Stage 1 electric heat (optional) Stage 1 heating compressor Stage 1 cooling compressor Ordering Notes 540-105N Siemens TEC Heat Pump Controller Single Stage 6 Siemens Industry, Inc.
Sequence of Operation Control Temperature Setpoints Sequence of Operation The following paragraphs present the sequence of operation for Application 2072 Heating & Cooling Heat Pump with Internal Reversing Valve & Mixed Air Control. Control Temperature Setpoints This application has a number of different room temperature setpoints (DAY HTG STPT, NGT CLG STPT, RM STPT DIAL, etc.). The application actually controls using the CTL STPT.
Sequence of Operation Room Temperature and CTL TEMP CTL STPT is calculated as follows: With Deadband Disabled: CTL STPT = Dial value With Deadband enabled in Heat Mode: CTL STPT = Dial value – 0.5 ∗ Deadband (limited between the value of RM STPT MIN and RM STPT MAX) With Deadband enabled in Cool Mode: CTL STPT = Dial value + 0.5 ∗ Deadband (limited between the value of RM STPT MIN and RM STPT MAX). NOTE: If RM STPT DIAL is failed, it maintains the last known value.
Sequence of Operation Day and Night Modes Day and Night Modes The day/night status of the space is determined by the status of DAY.NGT. The control of this point differs depending on whether the controller is monitoring the status of a wall switch or if the controller is connected to a field panel. When a wall switch is physically connected to the termination strip on the controller DI 2 (see the Control Diagram(s), and WALL SWITCH = YES, the controller monitors the status of DI 2.
Sequence of Operation Control Loops Digital Room Units (2200/2300 Series) The digital room unit will display a graphical bar indicating the number of steps above or below the current operating temperature setpoint. When the controller switches modes (heating to cooling) the span adjustment set will be applied to the new heating/cooling mode center value.
Sequence of Operation Control Loops Application 2072 Heating and Cooling Loops. Cooling Loop – CLG LOOPOUT must be greater than the value of FREE CLG ON before free cooling will be used. The controller accomplishes free cooling by enabling the mixed air loop to modulate the mixed air damper. CLG CMP 1 will not be allowed to turn ON until CLG LOOPOUT becomes greater than the value of CLG CMP1 ON. CLG CMP 1 will not be allowed to turn OFF until CLG LOOPOUT drops below the value of CLG CMP1 OFF.
Sequence of Operation Mixed Air Control not be allowed to turn OFF until HTG LOOPOUT drops below the value of HTG CMP1 OFF. When HTG LOOPOUT drops below the value of SWITCH LIMIT, the controller will be allowed to change to cooling mode if all other criteria for the change have been met. Mixed Air Loop – The heat pump is controlled by two Proportional, Integral, and Derivative (PID) control loops: a cooling loop and a heating loop.
Sequence of Operation Compressor Operation HEAT.COOL = HEAT. Free cooling is not needed in the heating season. MA TEMP is failed. When this point is failed, mixed air control is not possible. NGT MA CTL = NO. Mixed air control is not being used during the night mode. FREE CLG = DISABL. The outside air is too warm to be used for free cooling. CLG LOOPOUT < FREE CLG OFF. The cooling load is so small that no cooling is required.
Sequence of Operation Electric Heat (Optional) This application can support 0 or 1 cooling compressors (as defined by the value of CLG CMP TOTL) and 0 or 1 heating compressors (as defined by the value of HTG CMP TOTL). When HEAT.COOL = COOL, HTG LOOPOUT will be set to 0. CLG LOOPOUT will also equal 0 until the heating compressor has been OFF for at least the minimum OFF time. This is a safety feature that prevents the simultaneous operation of the heating and cooling compressor DOs.
Sequence of Operation Fan Operation Fan Operation NOTE: To prevent damage to the heat pump, the default setting of HP DO OVRD does not allow operator command of the fan. See the Overriding Critical Heat Pump DOs section for more information. Day Mode – FAN is ON when CYCLE FAN = NO. If CYCLE FAN = YES, the fan control in day mode is the same as it is in night mode.
Sequence of Operation Overriding DOs Overriding DOs This application is designed to prevent you from directly commanding critical DOs ON or OFF. Specifically, the fan, reversing valve, electric heat and compressor cannot be directly commanded ON or OFF. Commanding these DOs can only be done indirectly by overriding the output of the loop currently under control (either CLG LOOPOUT or HTG LOOPOUT). This is done to protect the equipment. You will be able to directly turn any spare DOs ON or OFF.
Sequence of Operation Wiring Diagrams Wiring Diagrams CAUTION The controller’s DOs control 24 Vac loads only. The maximum rating is 12 VA for each DO.
Application 2072 Point Database Application 2072 Point Database Point Number Descriptor Factory Default (SI Units) Eng Units (SI Units) Slope (SI Units) Intercept (SI Units) On Text Off Text 1 CTLR ADDRESS 99 -- 1 0 -- -- 2 APPLICATION 2090 -- 1 0 -- -- 3 RETURN DELAY 10 MIN 1 0 -- -- {04} ROOM TEMP 74.0 (23.45) DEG F (DEG C) 0.25 (0.14) 48.0(8.89) -- -- {05} HEAT.COOL COOL -- -- -- HEAT COOL 6 DAY CLG STPT 74.0 (23.45) DEG F (DEG C) 0.25 (0.14) 48.0(8.
Application 2072 Point Database Point Number Descriptor Factory Default (SI Units) Eng Units (SI Units) Slope (SI Units) Intercept (SI Units) On Text Off Text {42} DO 2 OFF -- -- -- ON OFF {43} ELEC HEAT OFF -- -- -- ON OFF {44} HTG CMP 1 OFF -- -- -- ON OFF {45} CLG CMP 1 OFF -- -- -- ON OFF {46} FAN OFF -- -- -- ON OFF {48} DMPR COMD 0 PCT 0.4 0 -- -- {49} DMPR POS 0 PCT 0.
Application 2072 Point Database Point Number Descriptor Factory Default (SI Units) Eng Units (SI Units) Slope (SI Units) Intercept (SI Units) On Text Off Text 83 HTG CMP1 OFF 30 PCT 0.4 0 -- -- 85 SWITCH LIMIT 4.8 PCT 0.4 0 -- -- 86 SWITCH TIME 10 MIN 1 0 -- -- 87 HTG1 MIN OFF 3 MIN 1 0 -- -- 88 HTG1 MIN ON 3 MIN 1 0 -- -- 90 SWITCH DBAND 2.0 (1.12) DEG F (DEG C) 0.25 (0.14) 0 -- -- {91} NGT MA CTL NO -- -- -- YES NO {92} CTL STPT 74.0 (23.
Issued by Siemens Industry, Inc. Building Technologies Division 1000 Deerfield Pkwy Buffalo Grove IL 60089 Tel. +1 847-215-1000 Document ID 140-1042 Edition 2014-05-01 © 2014 Copyright Siemens Industry, Inc. Technical specifications and availability subject to change without notice.
