Calibrate Valve Actuator, Select Control Algorithm

Advanced Microprocessor with Graphics Control Setup

4.7.2Select Options

The following table is a list of features that should match the options installed with your unit and should not need to change during normal operation.

Table 10 Select options

Option	Selection

Heating	Yes or No

Humidifier	Yes or No

Dehumidifier	Yes or No

Humidifier Pan	Small or Large

Hot Gas Reheat	Yes or No

Heat Stages*	2 or 3

Dehumidification Stages	1 or 2

*If heat stage is set to 2 on a chilled water unit, the reheat 3 output is energized on a call for dehumidification.

4.7.3Calibrate Sensors

The temperature and humidity sensors can be calibrated by selecting this menu item. “SENSOR” shows the actual sensor reading or raw reading. “CALIBRATED” shows the sensor reading after the calibration offset has been added. The temperature sensor can be calibrated ±5 degrees Fahrenheit and the humidity sensor can be calibrated ±10% RH. When calibrating the humidity sensor, the value shown will always be % RH, even though absolute humidity control may be selected. If absolute humidity control is selected, the Normal Status Display will display the adjusted reading and may not agree with the relative humidity reading displayed while in calibration.

4.7.4Calibrate Valve Actuator

For systems that use a valve actuator for chilled water or glycol cooling, the actuator timing may be calibrated or adjusted through this feature. This is the time it takes for the valve to travel from full closed to full open. It is programmable from 0 to 255 seconds. The factory default time is 165 seconds and should not be changed unless the actual valve travel time is not correct. The full valve travel time is used by the control to determine the appropriate valve position. For example, if the valve travel time is 165 seconds and 50% cooling is being called for, the valve will open for 83 seconds to achieve 50% open. To change the valve travel time, first enter the “CALIBRATE VALVE ACTUATOR” screen. The display will show the present period used by the control for valve actuator full travel. Press ENTER and adjust the time using the UP/DOWN arrows. When the correct time is displayed, press ENTER to store the new time in memory.

4.7.5Select Control Algorithm

The type of system control method used by the microprocessor can be selected from the front panel. The default setting is INTELLIGENT, which approximates the actions that a human operator would take to maintain precise, stable control. The control logic uses Artificial Intelligence techniques including “fuzzy logic” and “expert systems” methods to maintain precise, stable control and increase reliability by reducing component cycles. PROPORTIONAL is a standard control method that uses one gain factor (temperature sensitivity adjustment). TUNABLE PID (Proportional, Integral, and Derivative) uses three gain factors selected by the operator. PID allows precision tuning, but requires an experienced operator and seasonal adjustments. Note that if PID is selected, it is used for temper- ature control while humidity will continue to use Proportional Control. For chilled water units with the optional Variable Speed Drive, Intelligent is required for proper operation. Refer to 5.0 - Response by Control Type—Advanced Microprocessor Controls for more details on types of control.

VE, DH, VH, DE specifications

Emerson is a well-known brand in the field of automation solutions, offering a range of products that cater to various industries. Among its diverse portfolio, Emerson’s products like DE (Digital Electronics), VH (Variable Frequency Drives), DH (Distributed Control Systems), and VE (Valve Positioners) stand out for their advanced features, cutting-edge technologies, and unique characteristics.

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Variable Frequency Drives (VH) are integral to motor control technologies, maximizing energy efficiency in various applications. Emerson's VH drives are designed for flexibility, supporting multiple motor types and configurations. These drives utilize pulse width modulation (PWM) technology, allowing for precise speed control and improved application performance. Their built-in protection features help extend motor life, prevent downtime, and reduce maintenance costs. Furthermore, the user-friendly interfaces of VH drives facilitate quick setup and troubleshooting.

Distributed Control Systems (DH) from Emerson provide a holistic approach to managing complex industrial processes. They enable centralized control while ensuring that local operations continue seamlessly. DH systems are characterized by their modular architecture, making them highly scalable and adaptable to changing operational needs. Advanced control algorithms within these systems help optimize processes, ensuring maximum productivity. Additionally, their enhanced cybersecurity features protect critical industrial operations from potential threats.

Emerson's Valve Positioners (VE) play a crucial role in regulating flow and pressure in various processes. These devices provide precise positioning capabilities, enhancing the performance of control valves. The VE systems incorporate smart technologies such as adaptive control and diagnostics, allowing them to self-tune and deliver accurate performance over time. Their compact design and robust build ensure they operate effectively in challenging environments.

In summary, Emerson's DE, VH, DH, and VE offerings embody the latest innovations in automation technology. Their main features, including digital communication, energy efficiency, scalability, and precision control, cater to the diverse demands of modern industries. With these products, Emerson not only enhances operational efficiency but also paves the way for intelligent automation solutions that are crucial for the future of industrial processes.