Medium Voltage Products
Motor Protection
Bulletin 857 Advanced Motor/Feeder Protection
Maximize your motor’s output capabilities and provide current, voltage and motor protection functions with the Allen-Bradley Bulletin 857 Feeder/Motor protection relay. It protects feeders and motors in distribution networks of utilities, industry, power plants and offshore applications, and can be integrated into a Motor Control Center, or can be purchased as an OEM component.
The device also includes programmable functions such as thermal protection, trip circuit supervision, circuit breaker protection, various communications protocols, and optional arc protection.
Bulletin 857 Feeder/Motor Protection Relay benefits:
- Wide setting ranges for protection functions can reach a sensitivity of .5%.
- Fully digital signal handling with a powerful 16-bit microprocessor and high measuring accuracy on all the settings ranges due to a 16-bit A/D conversion technique.
- Integrated fault location for short-circuit faults.
- The device can be matched to the requirements of the application by disabling the functions that are not needed.
- Flexible control and blocking possibilities due to digital signal control inputs (DI) and outputs (DO).
- Easy adaptability of the device to various substations and alarm systems due to flexible signal-grouping matrix in the device.
- Possibility to control six objects (e.g. circuit-breakers, disconnectors).
- Status of eight objects (e.g. circuit-breakers, disconnectors, switches).
- Freely configurable display with six selectable measurement values.
- Freely configurable interlocking schemes with basic logic functions.
- Recording of events and faults values into an event register from which the data can be read via a keypad and a local HMI for by means of a PC based configuration software.
- All settings, events and indications are in non-volatile memory.
- Easy configuration, parameterization and reading of information via local HMI or with a SetPointPS user interface.
- Easy connection to automation systems via versatile serial connection and several available communications protocols.
- Built-in, self-regulating ac/dc converter for auxiliary power supply from any source within the range from 40 to 265 VDC or VAC.
- Built-in disturbance recorder for evaluating all the analogue and digital signals.