Basler BE1-51 microcomputer time limited overcurrent relay

Basler BE1-51 microcomputer time limited overcurrent relay

Chapter 1 General Information and Electrical/Mechanical Specifications

1. Core standard functions

(1) Time limited overcurrent (51 components)

The current start range (TAP) is divided into high and low ranges, with a total of 10 levels from A to J. It is paired with a single turn TAP CAL potentiometer to achieve continuous fine adjustment between levels;

Delay dialing TIME DIAL range from 00 to 99, supporting 69 international standard protection curves;

Two timing algorithms: non integral timing Z1/Z2 (real-time update delay of current changes), integral timing Z3 (simulating the cumulative characteristics of traditional electromechanical relays I ² t).

(2) Instantaneous overcurrent (50 components)

Optional 1-channel INST1 and 2-channel INST2 instantaneous components, with adjustable starting values ranging from 1 to 40 times the time limit TAP set current, can quickly cut off short-circuit faults without delay; Three phase model independent neutral instantaneous adjustment knob.

(3) Neutral Defeat

The panel switch can temporarily turn off the neutral circuit overcurrent protection, which is used for system three-phase imbalance debugging. After the switch is turned on, the neutral current will not trigger a trip.

(4) Auxiliary supporting functions

Fault LED target indicator: distinguish time limit, instantaneous, phase/neutral faults, electronic latch, panel reset key to reset to zero; There are two types: internal drive and trip circuit current drive;

8-way output contacts: standard timed tripping, instantaneous tripping, auxiliary alarm, contacts with clear breaking capacity for AC and DC loads;

Built in BIT self-test circuit for fault diagnosis and calibration.

2. Classification of current sampling range

Divided into 9 sampling specifications, suitable for 1A and 5A standard CT:

Basic high and low gears: Low gear 0.1~2.4A/High gear 0.5~12A;

The three-phase neutral model supports independent range combinations of phase and neutral (four combinations including phase 1.5~12A+neutral 0.5~4A);

Input burden<0.1 Ω, short-term withstand 50 times the gear current or 500A (whichever is smaller).

3. Power specifications (5 types of power supply selection)

R：24Vdc； O：48Vdc； P：120Vac/125Vdc； S: 48/125V AC/DC universal; T：240Vac/250Vdc， Power consumption ranges from 1.6 to 14.2VA, supporting redundant AC and DC power supply.

4. Electrical accuracy indicators

Time limit starting value error: ± 2%, after full range adjustment of potentiometer, it is ≤ ± 5%;

Instantaneous startup error: ± 2%;

Delay accuracy: standard curve ± 5%, 25 ℃ repeatability error ± 2%;

Instantaneous action response is extremely fast, providing a standard action time curve.

5. Mechanical and environmental parameters

Structure: Pull out rack unit, two types of installation (semi embedded/protruding S1 cabinet);

Weight: 5.9kg for single-phase, 6.53kg for three-phase neutral;

Temperature range: working -40~+70 ℃, storage -65~+100 ℃;

Immunity: Meets ANSI/IEEE C37.90 standards for surge, electrostatic, and radio frequency interference, and has UL and GOST-R certifications.

Chapter 2 Front Panel Controls and Indicator Lights

1. Definition of all components of the panel

TAP gear selection switch: phase/neutral independent, 10 levels of reference current;

TAP CAL Fine tuning Potentiometer: Single turn, continuous fine tuning of starting current between gears;

INST1/INST2 four turn potentiometer: adjust 1-40 times the instantaneous current of TAP;

TIME DIAL dual digit dialing: 00~99 select delay scale; Neutral independent delay dialing;

Neutral Defeat switch: shielded neutral protection, matched with status LED;

Function LEDs: TIMING start indicator light, phase A/B/C/N fault lights, time limit/instantaneous fault latch target light;

Reset button: Clear all latch fault indications;

PUSH-TO-ENERGIZE hidden test button: Pressing the insulation tool directly drives the output contact to verify the external trip circuit;

Power running LED;

Select the dip code for the internal motherboard curve of the body (Z1/Z2/Z3 models).

2. Menu/Parameter Matching Table

Table 2-2: Corresponding values of high and low range currents for all gears;

Table 2-3: Configuration rules for fault indicator lights corresponding to different sampling models;

All modifications require password/permission control, and key protection parameters are prohibited from being changed arbitrarily.

Chapter 3 Functional Principle Block Diagram of the Whole Machine

1. Hardware signal link

CT secondary current → multiplexer → 12 bit ADC analog-to-digital conversion → microprocessor+DSP operation, respectively calculating time limit, instantaneous, and neutral overcurrent logic, driving output relays.

2. Disassembly of core modules

Current sampling multiplexing: collect A/B/C three-phase+neutral current by polling, and unify analog digital conversion;

Timing algorithm differentiation

Non integral (Z1/Z2): Calculate the remaining delay in real-time based on the current multiple, and update the trip time immediately when there is a sudden change in current;

Integral (Z3): Continuous accumulated current multiplied by time equivalent, simulating the inverse time characteristic of old-fashioned electromagnetic relay I ² t;

Neutral shielding logic: After the switch is closed, the neutral sampling signal is directly shielded and does not participate in the protection judgment;

Output driver: time limited tripping, instantaneous tripping, multi-channel auxiliary alarm relay;

Locking target circuit: LED self-locking occurs when a fault occurs, it will turn off when power is cut off, and the fault record will not be retained when power is restored;

Internal self-test BIT: Hardware faults in the acquisition and output circuits during power on/manual verification of the entire machine.

3. Output contact logic

Main tripping contact: Close the driving circuit breaker 52 tripping coil after time limit/instantaneous action;

Auxiliary contact: can be used for remote alarm and fault signal upload;

The pull-out bracket comes with a short-circuit strip: when the relay is pulled out, it automatically short circuits the CT twice to prevent the danger of CT open circuit and high voltage.

Chapter 4 Installation, Wiring and Maintenance

1. Installation specifications

No mandatory requirement for vertical installation, any angle is acceptable;

Provide two types of cabinet opening size drawings: semi embedded and protruding;

Wire diameter ≥ 14AWG, grounding 12AWG copper wire independent grounding terminal;

The connection plug must be unplugged for maintenance/voltage test, and the CT secondary automatic short circuit must be performed.

2. Typical wiring diagram

There are four types of external CT wiring: single-phase, two-phase neutral, three-phase, and three-phase neutral; Instructions for internal terminal layout and use of short circuiting strips; Distinguish between high and low range terminal connections.

3. Maintenance requirements

No regular maintenance requirements, only regular functional verification of the entire machine;

Backup idle equipment: Power on for 30 minutes per year to extend the lifespan of electrolytic capacitors;

If the fault cannot be repaired, please contact Basler after-sales service. Disassembly without authorization is prohibited.

Chapter 5: Whole Machine Testing and Calibration (Standard Process for On site Operations)

1. Essential testing equipment

Relay protection tester (output ≥ 40A), AC/DC test power supply, high-precision stopwatch, shunt resistor (meeting the minimum driving current of 200mA for fault indicator light).

2. Four standardized testing procedures

Time limited overcurrent start-up test

Verify the lowest and highest gears of TAP separately, adjust them through CAL potentiometer, and measure the starting current error to be ≤ ± 5%; Test phase separation and neutrality one by one.

Neutral shielding function test

Apply 2 times the neutral gear current, and when the switch is closed, it will trip normally with a delay. After being turned on, there will be no action to verify the shielding function.

Time delay accuracy test

Set a fixed current multiple (5 times TAP), modify the TIME DIAL (20/40/60/99) measured action time, compare with the curve in the appendix with an error of ≤ 5%, and verify phase separation and neutrality separately.

Instantaneous overcurrent start-up test

Adjust the INST knob to the minimum (1 times) and maximum (40 times) to apply current, verify the accurate operation of the instantaneous components, and support independent testing of dual instantaneous components.

3. On site setting operation steps

Complete the following steps in sequence: gear TAP setting → CAL fine-tuning → curve motherboard dialing selection → delay dial TIME DIAL setting → INST instantaneous value setting, with each step accompanied by testing and verification, providing complete step-by-step instructions for operation.

Appendix A Time limited Overcurrent Characteristic Curve Library (Core Engineering Tool)

1. Three major selection series for curves

Z1: General inverse time curve (7 for Class B, 8 for Class I ² t C);

Z2: Z1 all curves+5 British BS142 standard Class E curves;

Z3: All curve integration I ² t algorithm version, simulating electromechanical relays.

List of Curve Types

B series (universal inverse time limit): short inverse, long inverse, definite time limit, moderate inverse, standard inverse, severe inverse, extreme inverse, standard I ² t;

C series (with 8 levels of restricted I ² t curve);

E series (BS142 British Standard Curve);

Each curve is divided into two versions: standard delay and extended delay (approximately 5.7 times the duration), with a total of 69 standard curve graphs. The horizontal axis represents current multiples (1.5-20 times TAP), and the vertical axis represents action time (seconds). The 00~99 dial scales are all marked with corresponding delays.

Supporting tables: Comparison table of curve dialing positions, list of supported curves for each Z motherboard, used for on-site calibration and table lookup.