Basler BE1-DFPR feeder protection relay

Overvoltage (59): If any phase voltage exceeds the set value and exceeds the delay, it triggers a trip.

Underfrequency (81): When the frequency is below the set point of 81T HZ and lasts for 81T TD seconds, it trips; The frequency will automatically coincide after being restored to 81R HZ for 81R TD seconds.

4. Circuit breaker monitoring and maintenance data

Trip Circuit Monitoring (TCS): Continuously detects the continuity of the trip coil through terminals 34/35. When interrupted, an alarm will be triggered and the reclosing will be locked to the "locked" state.

Circuit breaker status monitoring: Determine the validity of the circuit breaker position by verifying the consistency of the auxiliary contacts of 5a/56a.

Maintenance log: Record the number of circuit breaker operations and cumulative breaking current (I ² or accumulated value of I), providing data support for status maintenance.

Fixed value group and adaptive protection

BE1-DFPR supports up to 5 independent fixed values (Normal, Aux 1/CLP, Aux 2/EP, Aux 3, Aux 4), which can be automatically switched through external programmable inputs (USR1-USR5) or internal logic to achieve adaptive protection strategies:

Aux 1 (cold load start): Used for suppressing load surge when power is restored after a long power outage on the line. It can be automatically activated by setting the "cooling load time" and automatically switch back to the normal setting after 10 minutes.

Aux 2 (emergency operation): highest priority, used for hotline maintenance or personnel safety oriented protection settings under special working conditions, requiring external input to enable.

This design enables DFPR to dynamically adjust protection coordination based on system operating status, avoiding conflicts in setting values of traditional relays under special operating conditions.

Key points of installation and wiring engineering

1. Chassis installation

BE1-DFPR adopts a standard 19 inch rack mounted installation, with a height of 8.75 inches (5U) and a depth of 8.2 inches (behind the panel). Supporting horizontal or vertical installation, the panel opening size is shown in Figure 4-2. The maximum weight of the entire machine is 35 pounds (approximately 15.9kg), and the load-bearing capacity of the rack must be ensured during installation.

2. Wye/Delta toggle switch

The three-phase/single-phase voltage switch located behind the magnetic component panel is the most overlooked key link in on-site wiring:

For the four wire Wye wiring (phase neutral), place the switch in the Wye position.

For the three wire Delta wiring (phase to phase), place the switch in the Delta position.

After changing the switch position, it is necessary to synchronously modify the 3/1 PH WYE/DELTA setting items in "INSTALLATION SETTINGS" (1=single-phase/Wye, 2=three-phase/Delta, 3=single-phase B-phase voltage).

3. Testing plugs and uninterrupted maintenance

There is a set of standard connection plugs (optional accessories) located under the front cover of the magnetic component. After removing these plugs and replacing them with test plugs (Basler P/N 10095 or GE XLA12A), the current/voltage input and tripping/closing output circuits will be completely isolated, allowing for verification or fault simulation without the relay being powered on - this is extremely valuable for regular maintenance and upkeep of operational sites.

Communication and Debugging Access

DFPR provides front and rear dual RS-232-C ports (DB-9), with the front port automatically disabled after insertion to prevent conflicts. The communication parameters are as follows:

Baud rate: 300-19200 optional

Data bit 8, stop bit 2, no checksum

Terminal simulation: DEC VT-100 compatible

Software flow control (XON/XOFF) enabled

Through standard serial terminal software such as Windows Terminal or Procomm, all functions such as viewing and editing fixed values, downloading event records, and reading real-time measurement values can be accessed. Important safety reminder: The write life of non-volatile memory (EEPROM) is limited (about 100000 times), and frequent modification of settings through communication ports may shorten the device's service life. Unnecessary repeated write operations should be avoided.

On site testing and verification process

Chapter 5 of the manual provides detailed testing procedures, including setting value verification, action time verification, and logic function testing. The following are the core testing points:

1. Pickup Verification of Setting Values for Each Component

Overcurrent (51/50/50T): Apply single-phase or three-phase current through a three-phase relay protection tester, and confirm item by item that the deviation between the actual operating current and the set value is within the allowable range (51 is ± 2%, 50/50T is ± 5%).

Undervoltage/Overvoltage (27/59): Under the premise of applying rated voltage, slowly adjust the single-phase voltage to the set value, and confirm that the action voltage deviation is ≤ 2%.

Underfrequency (81): Apply rated voltage and adjustable frequency signal, slowly reduce the frequency to the set value of 81T HZ, confirm that the action frequency deviation is ≤ 0.01Hz; then increase the frequency to 81R HZ, confirm the automatic coincidence function.