TEC Controller Constant Volume with Hot Water Reheat, Application 2033 Application Note 140-1023 2015-08-07 Building Technologies
Table of Contents Overview ............................................................................................................................. 4 Hardware Inputs .................................................................................................................. 5 Hardware Outputs ................................................................................................................ 5 Secure Mode Operation.......................................................................
Overview Hardware Inputs Overview In Application 2033, the controller provides a constant volume of air to the room during occupied periods, and a lower constant volume of air to the room during unoccupied periods. Reheat is provided by modulating a hot water valve. In order for the application to work properly, the central air handling unit must provide pre-conditioned air to the terminal box. Application 2033 Control Drawing. Application 2033 Control Schedule. 4 Siemens Industry, Inc.
Overview Hardware Inputs Hardware Inputs Analog Air velocity sensor Room temperature sensor (Optional) Room temperature setpoint dial (Optional) Auxiliary temperature sensor (100K thermistor) Digital (Optional) Night mode override (Optional) Wall switch Hardware Outputs Analog None Digital (Optional) Autozero Module Damper actuator Valve actuator Secure Mode Operation Secure Mode prevents unauthorized users from making changes to the TEC through the HMI port or room sensor.
Sequence of Operation Control Temperature Setpoints Sequence of Operation The following paragraphs present the sequence of operation for Application 2033 -Hot Water Reheat. Control Temperature Setpoints Depending on the controller’s current operational mode (occupied or unoccupied), CTL STPT holds the value of one of the following setpoints. NOTE: This application does not automatically switch between heating and cooling.
Sequence of Operation Control Temperature Setpoints The setpoint deadband exists to allow the controller to provide a separation of the heating and cooling temperature setpoints when a setpoint dial is enabled. The setpoint deadband is the difference between the cooling and heating day setpoints (DAY CLG STPT - DAY HTG STPT). The setpoint deadband can be disabled by setting DAY HTG STPT equal to DAY CLG STPT. When DAY HTG STPT does not equal DAY CLG STPT, a setpoint deadband (or zero energy band) is used.
Sequence of Operation Room Temperature and CTL TEMP CTL STPT Using Standard/Absolute Mode (Digital Room Unit, Revision 26 and later) Digital Room Unit (2200/2300 Series Firmware Revision 26 and later) When STPT SPAN is set to 0, the room setpoint adjustment on the digital room unit functions in a standard mode. The range of the adjustment is based on RM STPT MIN and RM STPT MAX. CTL STPT is set equal to RM STPT DIAL.
Sequence of Operation Control Loops Control Loops Flow Loop – maintains the point FLOW STPT by modulating the supply air damper point, DMPR COMD. The flow loop maintains the airflow at either OCC FLOW or UNOCC FLOW depending on the value of OCC.UNOCC. To enhance stable flow control, an advanced algorithm is used to calculate a controllable setpoint as the value approaches zero cfm (lps). FLOW is the input value for the flow loop.
Sequence of Operation Fail Mode Operation At the end of a calibration sequence, CAL AIR automatically returns to NO. A status of NO indicates that the controller is not in a calibration sequence. The Autozero Module is enabled when it is wired to DO 6 and CAL MODULE is set to YES. Fail Mode Operation If the air velocity sensor fails, the controller determines the status of FAIL MODE and positions the damper accordingly. If FAIL MODE = OPEN and the velocity sensor fails, the damper will open.
Sequence of Operation Wiring Diagrams Wiring Diagrams NOTE: The controller’s DOs control 24 Vac loads only. The maximum rating is 12 VA for each DO. An external interposing relay is required for any of the following: • VA requirements higher than the maximum • 110 or 220 Vac requirements • DC power requirements • Separate transformers used to power the load (for example, part number 540-147, Terminal Equipment Controller Relay Module) Application 2033 – Constant Volume with Hot Water Reheat.
Application 2033 Point Database Application 2033 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 2092 -- 1 0 -- -- {04} ROOM TEMP 74.0 (23.44888) DEG F (DEG C) 0.25 (0.14) 48.0(8.88888) -- -- {05} HEAT.COOL COOL -- -- -- HEAT COOL 6 OCC CLG STPT 70.0 (21.20888) DEG F (DEG C) 0.25 (0.14) 48.0(8.
Application 2033 Point Database Point Number Descriptor Factory Default (SI Units) Eng Units (SI Units) Slope (SI Units) Intercept (SI Units) On Text Off Text {41} DO 1 OFF -- -- -- ON OFF {42} DO 2 OFF -- -- -- ON OFF {43} DO 3 OFF -- -- -- ON OFF {44} DO 4 OFF -- -- -- ON OFF {45} DO 5 OFF -- -- -- ON OFF {46} DO 6 OFF -- -- -- ON OFF {48} DMPR COMD 0 PCT 0.4 0 -- -- {49} DMPR POS 0 PCT 0.
Application 2033 Point Database Point Number Descriptor Factory Default (SI Units) Eng Units (SI Units) Slope (SI Units) Intercept (SI Units) On Text Off Text 95 CAL SETUP 4 -- 1 0 -- -- 96 CAL TIMER 12 HRS 1 0 -- -- 97 DUCT AREA 1.0 (0.09292) SQ. FT (SQ M) 0.025 (0.002323) 0 -- -- 98 LOOP TIME 5 SEC 1 0 -- -- {99} ERROR STATUS 0 -- 1 0 -- -- 1) Points not listed are not used in this application.
Issued by Siemens Industry, Inc. Building Technologies Division 1000 Deerfield Pkwy Buffalo Grove IL 60089 Tel. +1 847-215-1000 Document ID 140-1023 Edition 2015-08-07 © Siemens Industry, Inc., 2015 Technical specifications and availability subject to change without notice.
