Selection and commissioning of Basler BE3-25 synchronous inspection relay

If the output contacts are stuck or burned due to insufficient contact capacity, the high current closing coil is directly driven by an external intermediate relay, which drives the closing coil; Check the DC circuit freewheeling diode

Loosening or aging of the set angle drift potentiometer and tightening of the potentiometer lock cap; If the repeatability is poor, replace the relay

Comparison with the replacement of old electromechanical synchronous relays

Many old-fashioned distribution panels still use electromagnetic synchronous inspection relays such as GE 25A and Westinghouse SCA. When replacing with BE3-25, please note:

Input impedance: The coil impedance of the electromechanical relay is relatively low (about k Ω), while BE3-25 has a high impedance (<4VA), which has little impact on PT load and does not require recalculating CT/PT errors.

Setting method: Electromechanical type uses a dial or tap, BE3-25 uses a potentiometer for continuous adjustment, more precise.

Response time: Electromechanical type is usually faster (<100ms), BE3-25 is 500ms, which may be unfavorable for fast parallel operation. At this time, it is necessary to adjust the slip or choose high-speed type (if available).

Dead bus function: Older models often do not have it and require additional installation of undervoltage relays, while BE3-25- ***** 5 is directly integrated to simplify the circuit.

Installation and maintenance precautions

Installation direction: No special requirements, but should be kept away from strong electromagnetic interference sources (such as high current busbars and frequency converters).

Grounding: The casing must be reliably grounded to prevent induced voltage interference with internal logic.

Environmental temperature: Not specified in the manual, but Basler products typically range from -40 ° C to+70 ° C and are suitable for harsh environments.

Regular verification: It is recommended to conduct a functional test once a year, including voltage difference, phase angle, and dead bus function, and record the action values to compare and verify the drift situation with the previous test.

Storage: If stored as a spare part for a long time, no special maintenance is required (solid-state capacitor aging problem), but moisture should be avoided.

Selection decision tree

Is it necessary to allow the busbar to start due to voltage loss when parallel

Yes → Choose BE3-25- ***** 5

No → Select BE3-25- ***** 4

Voltage levels: 120V, 240V, 380V, 480V (confirm PT secondary voltage).

Frequency: 50/60Hz standard, or 400Hz special.

Do you need an auxiliary power supply? BE3-25 is self powered and does not require an additional power supply, simplifying wiring.

Contact form: usually single pole double throw. If double break or large capacity is required, an external relay can be connected.