BASLER ELECTRIC BE1-851 OVERCURRENT PROTECTION RELAY MECHANISM

BASLER ELECTRIC BE1-851 OVERCURRENT PROTECTION RELAY MECHANISM

The BE1-951 Overcurrent Protection System provides complete circuit protection with multiple

overcurrent elements and is intended for use in any directional or non-directional overcurrent application.

Its unique capabilities make it ideally suited for applications where:

• Applications that require low burden to extend the linear range of CTs.

• Applications that require high accuracy across a wide frequency range such as for motor,

generator, and generator step-up transformer protection, or in co-generation facilities.

• Applications that require the flexibility provided by wide settings range, multiple setting groups,

and multiple coordination curves in one unit.

• Applications that require the economy and space savings provided by a multifunction, multiphase

unit. This one unit can provide all of the protection, control, metering, and local and remote

indication functions required on a typical circuit.

• Applications that require directional control and fault locating.

• Applications requiring protection of an intertie between dispersed storage and generation facilities

(DSG) and a utility.

• Transformer backup applications where overexcitation protection is required.

• Applications that require communications and protocol support.

• Applications where the capabilities of a digital multifunction relay are required, yet draw out

construction is also desirable.

• Applications where bus protection is provided by a high-speed overcurrent blocking scheme on

the transformer bus mains instead of a dedicated bus differential circuit.

• Applications where the small size and limited behind-panel projection facilitates modernizing

protection and control systems in existing substations.

• Applications using Ethernet communication, programmable email notifications, and live metering

information via an embedded web server (with BESTnet option).

• Applications requiring Modbus/TCP Ethernet communications (with Modbus/TCP option).

Model and Style Number Description

General

The BE1-951 Relay electrical characteristics and operational features are defined by a combination of

letters and numbers that make up the style number. The model number, together with the style number,

describe the options included in a specific device and appear in the clear window on the front panel and

on a sticker located inside the case. Upon receipt of a relay, be sure to check the style number against

the requisition and the packing list to ensure that they agree.

Sample Style Number

Style number identification chart, Figure 1-1. defines the electrical characteristics and operational features

included in BE1-951 Relays. For example, if the style number were E3N1R0Y, the device would have the

following characteristics and features:

BE1-951 —

(E) - 5 ampere nominal system with 5 ampere independent ground input

(3) - Three-phase voltage sensing

(N) - Not applicable

(1) - 48/125 Vac/Vdc power supply

(R) - Single ended case, normally open alarm output

(0) - ASCII over RS-485. No Ethernet

(Y) - 4000 point Data Array

Figure 1-1. Style Chart

Operational Specifications

BE1-951 relays used in a 50/60 Hz system have the following features and capabilities. For 25 Hz

operational specifications, refer to Appendix D, 25 Hz Operational Specifications.

Metered Current Values and Accuracy

5 Aac Nominal Range ..................................................... 0.5 to 15 Aac

1 Aac Nominal Range ..................................................... 0.1 to 3.0 Aac

Accuracy ......................................................................... ±1% of reading, ±1 least significant digit at 25°C

Temperature Dependence .............................................. ≤ ±0.02% per °C

Metered Voltage Values and Accuracy

3-wire Range .................................................................. 0 to 300 VL-L

4-wire Range .................................................................. 0 to 300 VL-L

Accuracy (10 to 75 hertz)

50 V to 300 V .................................................................. ±0.5% of reading, ±1 least significant digit at 25°C

Temperature Dependence .............................................. ≤ ±0.02% per °C