Variable Air Volume Modular Assembly (VMA) …

1 Application Note Issue Date May 21, 2014 2014 Johnson Controls, Inc. Code No. LIT-6375125 HVAC PRO Software Release Variable Air Volume Modular Assembly (VMA) 1400 Series Using Variable Air Volume Modular Assembly (VMA) 1400 Series Applications .. 2 Introduction .. 2 Key Concepts .. 3 VMA Controller .. 3 Theory of Operation .. 7 Application Logic .. 11 Flow Setpoint Configuration .. 19 VMA Single Duct Applications .. 21 VMA Dual Duct Applications .. 27 VMA Diagnostics .. 41 Detailed Procedures.

2 45 Creating a VMA Single Duct Application .. 45 Creating a VMA Dual Duct Application .. 56 Changing the VMA Parameter View .. 63 Configuring a VMA Application .. 64 Commissioning a VMA Application .. 64 Testing and Balancing a VMA Single Duct Supply/Exhaust Application .. 65 Testing and Balancing a VMA Dual Duct Application .. 68 Troubleshooting .. 73 VMA Firmware Revisions .. 78 Attributes and Parameters .. 80 Input/Output Options .. 80 VMA Single Duct Parameters .. 89 VMA Dual Duct Parameters.

3 111 Variable Air Volume Modular Assembly (VMA) 1400 Series Application Note 2 Using Variable Air Volume Modular Assembly (VMA) 1400 Series Applications Introduction The Variable Air Volume Modular Assembly (VMA) 1400 Series is an integrated module that includes a controller, differential pressure sensor, and actuator (except VMA1430 models, which are intended to be used with an external actuator). N o te : This document focuses on the VMA1410, 1420, and 1430 controllers. The VMA1400 Series also includes the VMA1440, which is used exclusively as part of the Metasys Zoning Package.

4 Refer to the Metasys Zoning Package Product Bulletin (LIT-639050) and the Metasys Zoning Package Overview Technical Bulletin (LIT-639100) for information on this specialized product. This application note introduces the VMA controller and provides procedures for the creation, configuration, and commissioning of single duct and dual duct applications. This document describes how to: create a VMA single duct application create a VMA dual duct application change the VMA parameter view configure a VMA application commission a VMA application test and balance a VMA single duct supply/exhaust application test and balance a VMA dual duct application Variable Air Volume Modular Assembly (VMA) 1400 Series Application Note 3 Key Concepts VMA Controller Description The Variable Air Volume Modular Assembly (VMA)

5 Models VMA1410 and VMA1420 are integrated modules that include the controller, actuator, and differential pressure sensor. The VMA1430 includes the controller and differential pressure sensor and is designed for use with a floating/3-wire (incremental) external actuator or proportional external actuator. The VMA applications are developed using standard objects, Assembly objects and application objects created by the Metasys system application basic programming language. These applications are built using Configuration Tools Release or later, and are downloaded to the VMA.

6 The VMA1430 is supported at Configuration Tools Release or later. N o te : This document focuses on the VMA1410, 1420, and 1430 controllers. The VMA1400 Series also includes the VMA1440, which is used exclusively as part of the Metasys Zoning Package. Refer to the Metasys Zoning Package Product Bulletin (LIT-639050) and the Metasys Zoning Package Overview Technical Bulletin (LIT-639100) for information on this specialized product. VMA1410 VMA1420 VMA1430 VMA14xx Figure 1: VMA Controller Models VMA applications can only be used with the VMA.

7 These applications cannot be downloaded to any other digital controllers, such as the Unitary (UNT), Variable Air Volume (VAV), or Air Handling Unit (AHU) controllers. Variable Air Volume Modular Assembly (VMA) 1400 Series Application Note 4 Integral Stepper Motor Actuator The stepper motor damper actuator is an integral part of the VMA1410/1420. The stepper motor provides a fast and accurate method of controlling the damper actuator. At startup, the VMA is programmed to perform an autocalibration procedure.

8 This procedure occurs on a Variable time delay determined by the N2 address. Autocalibration corrects for pressure sensor drift and ensures the stepper is synchronized. As part of the initial autocalibration, the stroke time of the integral actuator is calculated based on the time required to move from the open end-stop to the closed end-stop. The stroke time should be roughly equal to one of the following: 30 seconds for 90 degree dampers 20 seconds for 60 degree dampers 15 seconds for 45 degree dampers The VMA requires physical end-stops on both ends of rotation for correct operation.

9 During normal operation, the actuator position feedback provides position information and diagnostics that can indicate a stuck damper or slippage at the damper shaft connection. For the dual duct application, the VMA1420 with an integral actuator (if used) must be used on the cold deck damper. External Damper Actuators The VMA1420/30 can control external floating/3-wire (Position Adjust Output [PAO]) or proportional damper actuators in VAV boxes, such as Trane company boxes. Two Binary Outputs (BOs) are used for each floating/3-wire (PAO) actuator.

10 One Analog Output (AO) is used for each proportional actuator. N o te : External actuators require configuration of the stroke time attribute for the actuator to operate properly. Variable Air Volume Modular Assembly (VMA) 1400 Series Application Note 5 Revisions Table 1 compares HVAC PRO software revisions and VMA application revisions. See the Troubleshooting section of this document for more information on VMA firmware revisions. Table 1: Revisions HVAC PRO Software Revision VMA Application Revision Description of Changes 2 Original Release 3 Units attribute added for flow parameters.