TEC Controller Single Compressor Heat Pump with Reversing Valve Control, Application 2070 Application Note 140-1040 2014-05-01 Building Technologies
Table of Contents Overview ............................................................................................................................. 4 Hardware Inputs .................................................................................................................. 5 Hardware Outputs ................................................................................................................ 5 Ordering Notes .............................................................................
Overview Hardware Inputs Overview In Application 2070, the controller controls a single stage compressor heat pump with a reversing valve. In addition to a compressor, this heat pump may also be equipped with electric heat for auxiliary heat and optional outdoor air damper can be provided for ventilation air. Application 2070 Control Diagram. Application 2070 Control Schedule. 4 Siemens Industry, Inc.
Overview Hardware Inputs NOTES: 1. See Fan Operation. 2. See Control Temperature Setpoints. 3. See Heating/Cooling Switchover. 4. See Compressor Operation.
Sequence of Operation Control Temperature Setpoints Sequence of Operation The following paragraphs present the sequence of operation for Application 2070 Single Compressor Heat Pump with Reversing Valve 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 2070 Heating and Cooling Loops. Cooling Loop – CLG LOOPOUT must be greater than the value stored in RVAL SWITCH before the reversing valve will switch from heating to cooling. When the reversing valve is in cooling mode, the compressor operates as a cooling compressor. COMPRESSOR will not be allowed to turn ON until CLG LOOPOUT becomes greater than CMP ON. COMPRESSOR will not be allowed to turn OFF until CLG LOOPOUT drops below CMP OFF.
Sequence of Operation Reversing Valve Operation Reversing Valve Operation NOTE: To prevent damage to the heat pump, the default setting of HP DO OVRD does not allow operator command of the reversing valve. See Overriding Critical Heat Pump DOs section for more information. The status of REV VALVE determines the operation of the heat pump’s compressors (heating or cooling). The reversing valve changes from heating to cooling when the following conditions have been met: HEAT.COOL = COOL.
Sequence of Operation Electric Heat (Optional) Electric Heat (Optional) NOTE: To prevent damage to the heat pump, ELEC HEAT you cannot send commands to the pump at the portable operator’s terminal or the field panel. If the reversing valve is in cooling mode, ELEC HEAT is OFF. If the reversing valve is in heating mode, ELEC HEAT turns ON when the output of the heating loop > the value of ELEC HEAT ON. The electric heat turns OFF when the output of the heating loop is less than COMP ON.
Sequence of Operation Overriding DOs RETURN DELAY is useful for water to air heat pumps because it allows the central equipment to be running before the heat pumps start coming back on-line. This gives the water loop a chance to stabilize its temperature before the compressors start using it and therefore minimizes the chance that the heat pumps will trip the high temperature/pressure alarms.
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 2070 Point Database Application 2070 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 2070 Point Database Point Number Descriptor Factory Default (SI Units) Eng Units (SI Units) Slope (SI Units) Intercept (SI Units) On Text Off Text {48} DMPR COMD 0 PCT 0.4 0 -- -- {49} DMPR POS 0 PCT 0.4 0 -- -- 51 MTR TIMING 130 SEC 1 0 -- -- 56 DMPR ROT ANG 90 -- 1 0 -- -- 58 MTR SETUP 0 -- 1 0 -- -- 59 DO DIR.REV 0 -- 1 0 -- -- 60 CYCLE FAN NO -- -- -- YES NO 63 CLG P GAIN 10.0 (18.0) -- 0.25 (0.
Application 2070 Point Database 1) Points not listed are not used in this application. 2) A single value in a column means that the value is the same in English units and in SI units. 3) Point numbers that appear in brackets { } may be unbundled at the field panel. * This point may be unbundled at the field panel as an input for monitoring purposes only. 17 Siemens Industry, Inc.
Issued by Siemens Industry, Inc. Building Technologies Division 1000 Deerfield Pkwy Buffalo Grove IL 60089 Tel. +1 847-215-1000 Document ID 140-1040 Edition 2014-05-01 © 2014 Copyright Siemens Industry, Inc. Technical specifications and availability subject to change without notice.
