Application Guide for Basler BE1-BPR Circuit Breaker Protection Relay

Front panel components (Figure 2):

POWER indicator light (green): Power supply is normal

CLOCK indicator light (red): Real time clock not set

50PU indicator light (red): Any overcurrent start value exceeded

ALARM indicator light (red): Relay diagnosis abnormal

TARGET indicator light (red): The output relay has been activated and the target information has been locked

2-line x 16 character LCD display screen: displays target, set value, status, and diagnostic information

5-key keyboard: PROG (programming), EDIT (editing) ▶ (Right/Select), ▼ (Down/Select), RESET (Reset)

3.2 HMI Menu Navigation

The main menu branches are as follows: TARGETS → RELAY SETUP → RELAY STATION → BREAKER STATION → TIMER LOG → FAILT LOG → MAINTENANCE. The right arrow key switches to the main menu, and the down arrow key enters the sub screen.

The four step process for modifying the set value is "Access → Modify → Save → Confirm": press the PROG key to enter programming mode (if password protection is enabled, prompt for password input), and use ▶ Use the ▼ key to locate parameters, use the EDIT key to modify values, and long press the PROG key for 2 seconds to bring up SAVE CHANGES? Prompt, select Y to save.

4 BESTlogic ™ Detailed Explanation of Programmable Logic

BEST logic is the core technology that distinguishes BE1-BPR from traditional relay protection devices. It allows users to define the relationship between output and input through Boolean logic equations, and can adapt to various protection requirements without replacing hardware.

4.1 Logical Variables and Equations

Naming convention for logical variables:

Variable meaning Variable meaning

I1~I7 contact inputs 1~7 O1~O5 physical outputs 1~5

F1~F3 fault detectors 1-3 O6~O12 virtual outputs 6-12

T1~T6 timers 1~6 O13~O15 dedicated virtual outputs

OA alarm virtual output

Logical operators: AND (or adjacent variable) OR（+）、NOT（/）。 For example, the logical equation * * LO1=(F1+F2) T1 */T3 * * means that when fault detector F1 or F2 is started, timer T1 outputs true and timer T3 outputs false, output 1 is closed.

The equation is expanded internally in the form of "sum of and terms", with a maximum of 4 OR terms allowed. If more items are needed, virtual output can be used as an intermediate expression.

4.2 Pre programmed logic scheme

The standard BE1-BPR comes with three pre programmed solutions:

BFL1: Three pole trip BF logic (no input/output latch), IN3~IN5 are BFI input start timer T1, IN6~IN7 are no current BFI input start T2, F3 is used for fracture arc detection, OUT4 is arc detection output.

BFL2: Three pole+single pole trip BF logic (with output latch, controlling timer limit operation window), IN6~IN7 are used for single pole trip BFI, supervised only by phase fault detector F1.

BFL3: Enhanced Lock Version BFL2, with both BFI input and output equipped with latch function.

The enhanced version provides additional BFL1E~BFL3E, with added circuit breaker protection output (O13 → OUT3) and external fault triggering (IN7 for recording COMTRADE waveforms).

4.3 Custom Logic Programming

Typical process for customizing logic:

Copy pre programming scheme: LN=BFL1

Rename: LN=BFL1_CUSTOM

Modify the equation (such as changing 52b to 52a): LO6=/I1/I2, LO12=F3/I1

Activation: LOGIC=BFL1_CUSTOM

Save: SAVE; Y

Circuit breaker diagnostic function (enhanced)

5.1 Contact Wear Monitoring (DLOG)

Calculate the cumulative breaking loss of each phase circuit breaker based on the I ² t integration principle:

D[p] = Σ(I[p][n]^2 × t_arc)

Among them, D [p] is the accumulated breaking value of the p-th phase, I [p] [n] is the RMS current at the n-th breaking, and t_arc is the arc time. DMAX is set by the user based on the manufacturer's data of the circuit breaker (unit: ampere square second, such as 2.0E6), and the cumulative value is stored in percentage form of DMAX. When D [p] exceeds 100%, a programmable diagnostic alarm is triggered.

5.2 Overheating protection for disconnecting resistors

For high-voltage circuit breakers with closing resistors, BE1-BPR tracks the number of resistor operations (RESOPS counter). Every time a disconnection operation is recorded, the counter is incremented by 1; Automatically decrease by 1 after the set reset time. When the cumulative number of operations reaches the MAXOPS set value, the output O13 is true and can be programmed as a lockout reclosing signal (BRO).

5.3 Fracture arc detection

Using a Type 2 moving average filter to detect line charging currents as low as 0.05A - When a circuit breaker flashover occurs (such as due to lightning strikes or loss of air pressure), the continuously flowing weak line charging current can be reliably detected. Logically, F3 is in phase with the position of the circuit breaker (IN1 reversed), and after a delay confirmation, drives OUT4 to trigger the reclosing of the arc extinguishing.

5.4 Timed Diagnostic Log (TLOG)

TLOG can record up to 40 events, with each event storing the remaining time and timestamp of the timer. A typical application is "margin recording" - recording the remaining time of the circuit breaker failure timer (MARGIN value in Figure 13) after the circuit breaker is normally opened and closed. By using the PTLOG command, alarm thresholds can be set for each timer. When the margin is too small, a diagnostic alarm will be automatically triggered, prompting operation and maintenance personnel to adjust the timer setting value.