Debugging and Testing of Basler BE1-700 Relay

Guide for On site Debugging and Functional Verification of Basler BE1-700 Digital Voltage Protection Relay

Abnormal voltage and frequency are common causes of equipment damage or system instability in power generation, distribution, and industrial power systems. The BE1-700 from Basler Electric is a digital multifunctional relay designed specifically for voltage protection. It integrates protection functions such as overvoltage, undervoltage, negative sequence overvoltage, overexcitation (V/Hz), frequency and synchronization detection, and is equipped with programmable logic, fault recording, and event recording capabilities. Its compact chassis and flexible communication interface make it an ideal choice for retrofitting old systems and building new equipment. This article is based on the technical manual of the relay, systematically sorting out its installation configuration, protection function setting, BESTCOMSPlus software operation, and on-site testing methods from the perspective of engineering application, providing a practical operation guide for relay protection engineers.

Product positioning and hardware version identification

BE1-700 is a pure voltage type digital protection relay (without current input), suitable for scenarios such as busbars, transformers, generators, incoming lines, and feeders that require voltage and frequency monitoring. It provides three-phase voltage input and one auxiliary voltage input, supports three-phase three wire or three-phase four wire wiring, and has IRIG-B clock synchronization, USB-C front-end port, and optional Ethernet communication.

Hardware version differentiation: The manual clearly states that the front panel communication port of hardware version 4 (current version) is USB-C, while the old versions (1-3) are RS-232. In terms of voltage/current input, the old version can choose voltage or current, while version 4 only has voltage input. The software package has also been upgraded to BESTCOMSPlus (replacing the old version of BESTCOMS). When selecting, it is necessary to confirm the version. The new firmware supports communication through both Modbus TCP and BESTCOMSPlus, and the Modbus protocol can be selected as Ethernet or RS-485 (user configurable).

Installation wiring and grounding specifications

BE1-700 adopts a fixed panel mounted chassis (non drawer type) with compact size (see manual size diagram). There is no need for vertical restriction during installation, any angle is acceptable, but the direction of the HMI display screen is fixed.

Key points of electrical wiring:

Voltage input: Three phase voltage is connected to terminals C13 (VA), C14 (VB), C15 (VC), and C16 (neutral point N). Auxiliary voltage Vx connected to C17 (polarity) C18。 Rated continuous voltage: three-phase 300V line, auxiliary 150V line.

Control power supply: connect A6 and A7, voltage range depends on the model (24/48/125/250 Vdc or 120/240 Vac), no polarity. When the power supply is normal, the green Power LED on the front panel lights up.

Contact input (IN1~IN4): Connect B1/B2, B3/B4, B5/B6, B7/B8, requiring external wet voltage (ranging from 5~200V depending on the model), polarity sensitive, pay attention to positive and negative.

Output contacts (OUT1~OUT5 and OUTA): OUT1~OUT5 are normally open (Form A), and OUTA is fail safe normally closed (power-off closed). Contact capacity: 30A/0.2s closing, 7A continuous, 0.3A disconnection (inductive).

Grounding: A copper wire of not less than 12 AWG must be used to connect to the grounding terminal of the enclosure, and it is recommended to independently lead to the grounding grid. EMI suppression: If the output drive coil is connected in parallel with a reverse diode at the coil end.

Insulation test warning: External wiring must be disconnected before conducting voltage withstand test, otherwise internal components may be damaged.

Software installation and initial connection

BE1-700 is configured and monitored through BESTCOMSPlus software. This software is based on NET Framework， Windows 7 SP1 and above systems are required, and 2GB of memory is recommended. Do not connect the USB cable before installation, otherwise it may cause the driver installation to fail. Download the installation package from the Basler official website, and the installation process will automatically install the USB driver and BE1-700 plugin.

Connection steps:

After installation, connect the PC to the front panel port of the relay using a USB-C cable, and then power on the relay.

Start BESTCOMSPlus, select the language, click on "New Connection" to choose BE1-700, then select USB Connection and Connect.

After successful connection, read the current settings and logic through "Download Settings and Logic from Device" for modification or backup.

Basic system parameter settings

Firstly, configure the nominal values of the system, which affect the baseline of all protection functions.

In BESTCOMSPlus, navigate to Settings Explorer → System Parameters → Power System:

Nominal Frequency: 50 or 60 Hz.

Nominal Phase Rotation: ABC or ACB (affecting negative sequence calculation).

Nominal Voltage: The equivalent voltage between the secondary side phase and neutral. For example, if the PT secondary line voltage is 120V (three-phase three wire), then the input here should be 120/√ 3 ≈ 69.3V. If it is three-phase four wire and the PT secondary phase voltage is 69.3V, then the input should be 69.3V.