Siemens Reyrolle 7PG21 Pilot wire current differential feeder protection

Product Description

Siemens Reyrolle 7PG21 Pilot wire current differentialfeeder protection

The 7PG21 is a three-phase unit differential protection usedto detect in zone phase and earth faults. The relay is applied to the overheadline and underground cable circuits as well as shorter circuits such asinterconnectors.

Features

Relays (and associated CTs) are installed at each end of theprotected circuit and connected together with dedicated metallic pilot wires.

This established protection system provides simple, robustprotection of proven performance facilitating straightforward installation,commissioning and maintenance.

Relays have 3 current inputs and are housed in E6 cases.

Additional relays and components can be added to the basicprotection to provide:

• Increased insulation level
• Pilot wire supervision to monitor the integrity of the pilot circuit.

 

Functions

Protection functions

• Current differential protection over a single pair of pilot wires

Supervision functions

• Optional pilot wire supervision
• Optional overcurrent guard (check)

Control functions

• Optional unstabilising / intertripping