Siemens SIPROTEC 5 7SD82 Line Differential Protection Relay

Siemens SIPROTEC 5 7SD82 Line Differential Protection Relay Suppliers,Exporters in India

ARP IMPEX is a supplier and exporter of Siemens SIPROTEC 5 7SD82 Line Differential Protection Relays in India. We handle requirements for overhead lines, underground cable circuits, utility substations, industrial power networks, protection-panel upgrades and replacement of existing Siemens relays.

The Siemens 7SD82 is a compact relay developed mainly for line differential protection in medium-voltage and high-voltage systems. It compares the current measured at each end of the protected line and trips when the difference indicates a fault inside that section.

The relay can protect short and long lines, including circuits with single-ended or multi-ended infeed. A properly configured 7SD82 scheme can cover up to six line ends. It can also include transformers or compensating coils within the differential protection zone.

The adaptive differential algorithm takes into account current-transformer errors, CT saturation and capacitive charging current. This is useful on long underground cables and mixed cable-overhead routes where charging current may otherwise affect the differential measurement.

Unlike the SIPROTEC 7SL82, which combines line differential and distance protection, the 7SD82 is mainly selected where line differential protection is the primary requirement. Directional overcurrent and other backup functions can be included, but distance protection is not its main commercial positioning.

The relay uses three-pole tripping and has a minimum tripping time of 19 ms. Its compact one-third 19-inch housing suits panels where the available space is limited, and the standard input and output arrangement is sufficient.

Protection data can be exchanged between line ends over optical fibre, two-wire connections or suitable communication networks. Applicable SIPROTEC 4 and SIPROTEC 5 devices can also operate within the same line-protection arrangement, which can help during staged relay replacement projects.

For Siemens SIPROTEC 7SD82 price and availability, share the complete Siemens article number, required quantity and destination country.

Technical Specifications

• Brand: Siemens
• Product family: SIPROTEC 5
• Model: 7SD82
• Product type: Numerical line differential protection relay
• Main application: Protection of overhead lines and underground cables
• Voltage application: Medium-voltage and high-voltage systems
• Primary protection: Line differential protection
• Line arrangement: Single-ended and multi-ended lines
• Maximum line ends: Up to six
• Trip arrangement: Three-pole tripping
• Minimum tripping time: 19 ms
• Current inputs: Four CT inputs
• Voltage inputs: Four VT inputs
• Binary inputs: 11 or 23, depending on the selected version
• Binary outputs: 9 or 16, depending on the selected version
• Housing width: One-third of a 19-inch rack
• Display: Small or large front display
• Hardware: Compact base module with fixed expansion limits
• Engineering software: Siemens DIGSI 5
• Communication: Integrated Ethernet with optional communication modules
• Communication expansion: Up to two plug-in modules
• IEC 61850: Reporting and GOOSE communication
• Redundancy: PRP and HSR on applicable configurations
• Environmental protection: Conformal-coated electronic modules

The 7SD82 does not accept the smaller one-sixth SIPROTEC 5 expansion modules. The binary I/O, display, auxiliary supply, communication ports and enabled functions must therefore be checked from the complete Siemens MLFB.

Protection Functions

Depending on the ordered configuration, the Siemens SIPROTEC 7SD82 can provide:

• Phase-selective line differential protection
• Directional overcurrent backup protection
• Phase and earth-fault protection
• Sensitive earth-fault protection
• Ground-fault detection in isolated networks
• Ground-fault detection in compensated-neutral networks
• Current-transformer saturation detection
• Charging-current compensation
• Fault-location functions
• Targeted overhead-line section reclosing
• Arc protection
• Underfrequency load shedding
• Active- and reactive-power protection
• Voltage and frequency monitoring
• Circuit-breaker control and interlocking
• Programmable trip, alarm and automation logic

The full function package depends on the ordered device. The model name alone does not confirm every optional protection, control or communication function.

Features

• Compact line differential relay for MV and HV systems
• Protects overhead lines, underground cables and mixed routes
• Suitable for lines with one or several feeding points
• Supports protection arrangements with up to six line ends
• Three-pole tripping with a minimum operating time of 19 ms
• An adaptive algorithm improves stability during CT errors and saturation
• Charging-current compensation supports long cable applications
• Transformers and compensating coils can remain inside the protected zone
• Directional protection functions provide backup coverage
• Fault-location information helps identify the affected line section
• Communication available through fibre, two-wire links and networks
• Can communicate with applicable SIPROTEC 4 and SIPROTEC 5 relays
• IEC 61850 options support substation automation projects
• PRP and HSR options support redundant Ethernet communication
• Compact housing helps save space inside the panel
• Conformal-coated boards suit demanding substation environments
• DIGSI 5 is used for settings, logic and commissioning
• Suitable for new installations and existing relay replacement

Applications

Siemens SIPROTEC 5 7SD82 Line Differential Protection Relays are used for:

• Medium-voltage connecting lines
• High-voltage transmission lines
• Overhead distribution lines
• Underground cable circuits
• Mixed cable and overhead-line routes
• Two-terminal line protection
• Multi-terminal and tapped lines
• Lines with up to six ends
• Radial distribution networks
• Ring electrical networks
• Meshed power systems
• Lines with transformers inside the protection zone
• Lines containing compensating coils
• Transformer feeder connections
• Utility transmission substations
• Utility distribution substations
• Industrial substations
• Captive power plants
• Renewable-energy grid connections
• Wind and solar power evacuation lines
• Plant interconnection cables
• Protection-panel retrofit projects
• Replacement of older Siemens line differential relays

The 7SD82 is particularly relevant where fast and selective protection is required only for the defined line section. Faults outside that zone should remain stable, while internal cable or line faults require quick isolation.

Siemens 7SD82 and 7SL82 Difference

Both models can provide line differential protection, but they serve different protection schemes.

• SIPROTEC 7SD82: Primarily a compact line differential protection relay
• SIPROTEC 7SL82: Combines line differential and distance protection in one compact device

The 7SD82 is generally considered when differential protection and directional backup functions are sufficient.

The 7SL82 is more relevant where the project specification requires both differential and distance protection within the same relay. The correct selection should follow the approved protection drawing and the relay installed at the opposite line end.

Information Required for Quotation

A request for only “Siemens 7SD82 Relay” is not enough to identify the complete configuration.

For an accurate quotation, share:

• Complete Siemens MLFB or article number
• Required quantity
• Destination country
• Required communication interface, where specified

For replacement enquiries, also share clear photographs of the front nameplate and rear terminals.

Details of the relay installed at the opposite line end are especially important. The protection communication interface, physical medium and device compatibility must match the existing scheme.

If the article number is unavailable, share the existing relay model, number of line ends and whether the communication link uses optical fibre, two-wire connection or a communication network.

Siemens SIPROTEC 5 7SD82 Supplier and Exporter in India

ARP IMPEX supplies Siemens SIPROTEC 5 7SD82 Line Differential Protection Relays for utilities, EPC contractors, switchgear manufacturers, protection-panel builders, power plants and industrial users.

We handle enquiries for Siemens 7SD82 line differential relays, underground cable protection relays, overhead-line differential protection, multi-terminal line protection, IEC 61850 line relays and replacement of existing Siemens numerical relays.

The Siemens SIPROTEC 7SD82 price depends on the complete article number, binary I/O arrangement, auxiliary supply, communication modules, enabled functions and ordered quantity.

Send the complete Siemens part number, quantity and destination country for price, availability and export quotation.