ANSI Device Numbers: Understanding Electrical Equipment Classification

_{September 3, 2023 by JoyAnswer.org, Category : Electrical Engineering}

What are the different ANSI device numbers? Learn about the different ANSI device numbers used to classify electrical equipment and devices in engineering and industry.

What are the different ANSI device numbers?

The American National Standards Institute (ANSI) device numbers are a standardized numbering system used to classify and identify electrical devices and equipment in power systems and industrial applications. These device numbers help engineers, electricians, and operators communicate and reference specific devices within a power system. Here are some of the most commonly used ANSI device numbers:

Device Number 1: Master Element - A device that initiates the opening or closing of electrical circuits. It's typically a protective relay.
Device Number 2: Time Delay Starting or Closing Relay - A relay with adjustable time delay settings used for motor protection and control.
Device Number 3: Checking or Interlocking Relay - A relay used to provide electrical interlocking of equipment to prevent dangerous conditions or incorrect sequences of operation.
Device Number 4: Master Contactor - A device used for remote control of circuits, typically a contactor.
Device Number 5: Stopping Device - A device used to stop or interrupt the operation of equipment, such as an emergency stop button.
Device Number 6: Starting Circuit Breaker - A circuit breaker that provides motor protection by limiting the number of starts or by providing locked rotor protection.
Device Number 9: Reversing Device - A device used to reverse the direction of rotation of a motor.
Device Number 12: Overspeed Device - A device that trips when a motor exceeds a preset speed limit.
Device Number 13: Synchronous Speed Device - A device used to monitor the speed of a synchronous motor and provide protection.
Device Number 14: Underspeed Device - A device that trips when a motor falls below a preset speed limit.
Device Number 21: Distance Relay - A protective relay used to measure the distance to a fault in a transmission line and initiate trip commands.
Device Number 24: Volts per Hertz Relay - A relay used to monitor the voltage-to-frequency ratio to protect against over-excitation of induction motors.
Device Number 27: Undervoltage Relay - A relay that operates when the voltage falls below a preset level.
Device Number 30: Annunciator Relay - A relay that provides visual and audible signals based on monitored conditions.
Device Number 32: Directional Power Relay - A relay used to monitor power flow and direction in electrical systems.
Device Number 40: Field Relay - A relay used to control field excitation in synchronous generators.
Device Number 50: Instantaneous Overcurrent Relay - A relay that trips a circuit breaker or disconnect switch when an instantaneous overcurrent is detected.
Device Number 51: AC Time Overcurrent Relay - A relay used for time-delayed overcurrent protection.
Device Number 59: Overvoltage Relay - A relay that operates when the voltage exceeds a preset level.

These are just a few examples of ANSI device numbers. There are many more device numbers covering various protective relays, control devices, and monitoring equipment used in electrical systems. Understanding these device numbers is essential for professionals working in the field of electrical engineering and power system protection.