HVAC BAS Controls Terminology

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central processing unit (CPU)

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A computer that receives sensor data, analyzes that data and sends out orders to actuators to do the work. A CPU executes a program that directs the functions of the control system by semiconductor switching.

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commissioning

Back

The process of confirming, testing and starting up new devices.

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corrective maintenance

Back

The process of repairing a device after a failure has already occurred.

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direct current (dc)

Back

Current flow in only one direction.

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Electrically erasable programmable read-only memory (EEPROM)

Back

A type of memory that can be erased and reprogrammed. An EEPROM chip on a computer board is read-only memory (ROM).

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Electromechanical device

Back

A mechanical device that is electrically operated.

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Energy utilization index (EUI)

Back

An energy usage comparison for buildings, expressed in British thermal unit (Btu) per gross square foot. It compares energy consumption from one building to another.

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Ethernet

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A system for managing computer networks.

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Feedback

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A measurement of the result of an action performed by the controller.

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Light-emitting diode (LED)

Back

An LED display provides the operator with error codes and other information about the condition of the control system.