Product Overview

The BEC-816KF is a microcomputer-based automatic transfer switch (ATS) device specifically designed for bus section breakers, bridge breakers, and incoming lines, enabling intelligent power source switching and automatic restoration. The device supports 8 voltage inputs and 6 binary inputs, with flexible communication interfaces. It can be installed independently in power distribution equipment or integrated into relay protection panels, forming a complete automation system together with other relay protection and automation devices.

Protection Function

The device offers a variety of ATS logic configurations to meet the automatic switching requirements of different power supply modes. The main functions include bus coupler ATS, dual-power mutual ATS, primary/standby power ATS, and automatic restoration, ensuring fast and reliable switching to the standby power source in the event of a main power supply fault, thereby maintaining power supply continuity.

Control Function

The device supports local and remote control operations, meeting the requirements of unmanned and smart substations. The main control functions include local/remote open/close operations, remote setting modification, remote protection enabling/disabling, and programmable protection/signal output configuration. The device also supports CT power harvesting and split trip functions for specific application scenarios.

Hardware

The device features 8 voltage channels and 6 binary input channels, allowing flexible connection of multiple power supply voltage signals and external status signals to meet the monitoring and control requirements of complex power supply configurations.

Application Scenario

Bus section breaker ATS

Bridge breaker ATS

Incoming line ATS

BEC-816KF ATS operation principle

Typical main connection schemes applicable to BZT logic

Mode 1: Bus Coupler ATS – Bus II Dark Standby (BZT1)

Applicable Scenario

During normal operation, Bus I is supplied by Incoming Line 1, Bus II is supplied by Incoming Line 2, and the bus coupler breaker 3DL is open. When Bus I loses voltage while Bus II remains energized, the device automatically trips the incoming line 1 breaker (1DL) and closes the bus coupler 3DL, allowing Bus II to supply Bus I via the bus coupler.

Charging and Discharging Conditions

Operating Sequence

1. Detects that Bus I is de-energized (voltage ≤ bus de-energized threshold) → BZT starts

2. After the "Trip working breaker 1DL delay" (setting range: 0–10 s) elapses, trips open 1DL

3. After confirming that 1DL is in the open position, and after the "BZT1 close standby breaker 3DL delay" elapses, closes 3DL

Mode 2: Bus Coupler ATS – Bus I Dark Standby (BZT2)

Applicable Scenario

This is symmetrical to BZT1. When Bus II loses voltage while Bus I remains energized, the device automatically trips the incoming line 2 breaker (2DL) and closes the bus coupler 3DL, allowing Bus I to supply Bus II via the bus coupler.

Charging and Discharging Conditions

Operating Sequence

1. Detects that Bus II is de-energized → BZT starts

2. After the "Trip working breaker 2DL delay" elapses, trips open 2DL

3. After confirming that 2DL is in the open position, and after the "BZT2 close standby breaker 3DL delay" elapses, closes 3DL

Mode 3: Incoming Line 2 as Standby for Incoming Line 1 – Line 1 Running, Line 2 Standby (BZT3)

Applicable Scenario

During normal operation, both Bus I and Bus II are supplied by Incoming Line 1 (1DL and 3DL are closed, 2DL is open), with Incoming Line 2 serving as the standby power source for the entire station. When both Bus I and Bus II lose voltage, the device trips open 1DL and closes 2DL, restoring power supply via Incoming Line 2.

Charging and Discharging Conditions

Operating Sequence

1. Detects that both Bus I and Bus II are de-energized → BZT starts

2. After the "Trip working breaker 1DL delay" elapses, trips open 1DL

3. After confirming that 1DL is in the open position, and after the "Close standby breaker 2DL delay" elapses, closes 2D

Mode 4: Incoming Line 1 as Standby for Incoming Line 2 – Line 2 Running, Line 1 Standby (BZT4)

Applicable Scenario

This is symmetrical to BZT3. During normal operation, both Bus I and Bus II are supplied by Incoming Line 2 (2DL and 3DL are closed, 1DL is open), with Incoming Line 1 serving as the standby power source for the entire station.

Charging and Discharging Conditions

Operating Sequence

1. Detects that both Bus I and Bus II are de-energized → BZT starts

2. After the "Trip working breaker 2DL delay" elapses, trips open 2DL

3. After confirming that 2DL is in the open position, and after the "Close standby breaker 1DL delay" elapses, closes 1DL

Mode 5: Primary/Standby Power ATS with Automatic Restoration (BZT5)

Applicable Scenario

During normal operation, both Bus I and Bus II are supplied by Incoming Line 1 (1DL and 3DL are closed, 2DL is open), with Incoming Line 2 serving as the standby power source for the entire station. When Incoming Line 1 loses power (both Bus I and Bus II are de-energized), the device trips open 1DL and 3DL, then closes 2DL. When Incoming Line 1 is restored (voltage returns), the system can automatically switch back to Incoming Line 1.

Charging and Discharging Conditions

Operating Sequence

1. Loss-of-Voltage Transfer (Incoming Line 1 Running → Incoming Line 2 Standby)

(1) Detects that both Bus I and Bus II are de-energized → BZT starts

(2) After the "Trip working breaker 1DL/3DL delay" elapses, trips open 1DL and 3DL simultaneously

(3) After confirming that both 1DL and 3DL are in the open position, checks whether Incoming Line 2 is energized

(4) After the "Close standby breaker 2DL delay" elapses, closes 2DL (if de-energized, issues "Standby line de-energized alarm")

2. Automatic Restoration (Incoming Line 2 Running → Incoming Line 1 Standby)

(1) Detects that Incoming Line 1 voltage has been restored

(2) After the "Trip standby breaker 2DL delay" elapses, trips open 2DL

(3) After confirming that 2DL is in the open position, after the "Close bus coupler breaker 3DL delay" elapses, closes 3DL

(4) After confirming that 3DL is closed, after the "Close working breaker 1DL delay" elapses, closes 1DL

(5) If 3DL fails to close, issues "3DL Close Failure" alarm and does not proceed to close 1DL