Siemens Reyrolle 7PG21 Pilot Wire Current Differential Feeder Protection

The 7PG21 Differential Feeder Protection is a three-phase unit differential protection used to detect in zone phase and earth faults. The relay is applied to the overhead line and underground cable circuits as well as shorter circuits such as interconnectors.

Features

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

This established protection system provides simple, robust protection 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 basic protection to provide:

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

Key Features 

• High transient stability
• High speed operation
• Low phase and earth fault settings
• Little or no variation of settings with pilot length
• In zone bleed off of up to % of rated load
• Easy to install, commission and maintain
• kV pilot isolation option
• Easily reconnected as either Solkor Rf or Solkor R
• Pilot Supervision schemes available
• Remote end injection intertripping via pilot cores available
• Test points at relay fascia
• Option of 15 kv pilot isolation
• Option of pilot supervision

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

The comprehensive range of Reyrolle products provides the total protection requirements of distribution markets and industrial applications – ranging from overcurrent protection via transformer protection and voltage control to a full spectrum of auxiliary and trip relays. The portfolio includes many famous products such as “Argus, “Duobias”, “Solkor”, “Rho, etc. Through successive generations, Reyrolle numerical products have been developed to increase value to system operators. Discover the portfolio!