Siemens SIPROTEC 5 7UT86 Three-Winding Transformer Differential Protection Relay

Siemens SIPROTEC 5 7UT86 Three-Winding Transformer Differential Protection Relay Suppliers,Exporters in India

ARP IMPEX is a supplier and exporter of Siemens SIPROTEC 5 7UT86 Three-Winding Transformer Differential Protection Relays in India. We handle requirements for transformer protection panels, utility substations, power plants, industrial electrical systems, replacement projects and new EPC installations.

The Siemens SIPROTEC 7UT86 is mainly selected for the protection of three-winding power transformers. It works as the main transformer protection relay and can be expanded for applications involving four transformer sides. This makes it more appropriate for complex transformer schemes than relays intended mainly for standard two-winding transformers.

The relay detects internal transformer faults and initiates fast tripping before the fault causes extensive damage. It can also provide restricted earth-fault protection, overcurrent backup protection and additional protection for connected cables, short lines and shunt reactors.

The 7UT86 compensates for transformer vector groups and changing tap positions. It remains stable during transformer energisation, external faults and current-transformer saturation, helping avoid unnecessary transformer trips.

Its modular construction allows the current inputs, voltage inputs, binary contacts and communication modules to match the protection scheme.

This is useful for three-winding transformers, autotransformers, phase-shifting transformers and other applications where a fixed relay arrangement may not provide enough measuring points.

Siemens DIGSI 5 is used for relay settings, logic, testing and commissioning. IEC 61850 and other communication options support connection with SCADA, station control and digital substation systems.

For the Siemens SIPROTEC 7UT86 price, availability or export quotation, share the complete Siemens article number, required quantity and destination country.

Technical Specifications

• Brand: Siemens
• Product family: SIPROTEC 5
• Model: 7UT86
• Product type: Modular transformer differential protection relay
• Main application: Three-winding transformer protection
• Expansion: Configurable for up to four transformer sides
• Main protection: Transformer differential protection
• Earth-fault protection: Up to three ground-fault differential functions
• Current measuring points: Up to seven three-phase and seven single-phase points
• Voltage measuring points: Up to seven three-phase and seven single-phase points
• Standard hardware: Two predefined variants
• Current inputs: 12 CT inputs in the standard variants
• Voltage inputs: Four VT inputs in the standard variants
• Binary inputs: 11 to 23, depending on hardware
• Binary outputs: 18 to 34, depending on hardware
• Housing width: Depends on the selected hardware arrangement
• Engineering software: Siemens DIGSI 5
• Communication: Up to four plug-in communication modules
• IEC 61850: Available for substation communication
• Construction: Modular SIPROTEC 5 hardware with expandable I/O

The exact input arrangement, binary contacts, housing, communication protocols and enabled protection functions depend on the complete Siemens MLFB or article number.

Main Protection Functions

Depending on the ordered configuration, the Siemens SIPROTEC 7UT86 can provide:

• Three-winding transformer differential protection
• Protection for transformers with up to four sides
• Autotransformer differential protection
• Restricted earth-fault protection
• Transformer inrush restraint
• Overexcitation supervision
• Transformer vector-group compensation
• Tap-position compensation
• Phase and earth overcurrent backup protection
• Voltage and frequency protection
• Arc protection
• Short cable and line protection
• Shunt-reactor protection
• Additional line differential or distance protection
• Programmable tripping, alarm and interlocking logic

The relay can combine the main transformer protection with selected backup functions, but the enabled functions must be confirmed in the ordered Siemens configuration.

Features

• Developed specifically for three-winding transformer protection
• Expandable for transformer arrangements with four sides
• Provides fast detection of internal transformer faults
• Restricted earth-fault protection improves sensitivity near the neutral point
• Inrush restraint helps prevent tripping during transformer energisation
• Stable performance during external faults and CT saturation
• Compensates for different transformer vector groups
• Adapts the operating characteristic to the transformer tap position
• Supports standard transformers, autotransformers and special transformers
• Additional current and voltage inputs support backup protection
• Expandable I/O suits complex transformer protection panels
• Up to four communication modules can be selected
• DIGSI 5 is used for settings, testing and commissioning
• IEC 61850 supports digital substation integration
• Programmable logic supports transformer alarms and interlocking
• Fault and disturbance records help investigate transformer trips
• Coated electronic modules support demanding site conditions
• Suitable for new panels, protection upgrades and relay replacement

The main commercial difference between the 7UT85 and 7UT86 is that the 7UT85 is centred on two-winding transformer applications, while the 7UT86 is designed specifically for three-winding transformers and can be expanded to four sides.

Applications

Siemens SIPROTEC 5 7UT86 Transformer Differential Protection Relays are used for:

• Three-winding power transformers
• Three-winding autotransformers
• Transformers with an additional tertiary winding
• Grid-coupling transformers
• Phase-shifting transformers
• Converter transformers
• HVDC transformers
• FACTS transformers
• Electric arc-furnace transformers
• Utility transmission substations
• High-voltage and extra-high-voltage substations
• Power-generation substations
• Captive power plants
• Industrial transformer protection panels
• Short cable and line protection
• Shunt-reactor backup protection
• Motor and generator differential backup protection
• Transformer voltage-control schemes
• Protection-panel retrofit projects
• Replacement of older Siemens transformer relays

The 7UT86 is particularly relevant where a three-winding transformer requires more current-measuring points, additional backup functions and flexible communication options within one protection platform.

Selecting the Correct Siemens 7UT86 Relay

“Siemens SIPROTEC 7UT86” does not identify one fixed relay configuration. The current inputs, voltage inputs, binary contacts, communication modules, housing width and enabled functions can differ between article numbers.

For an accurate quotation, share:

• Complete Siemens article number or MLFB
• Required quantity
• Destination country
• Communication requirement, where applicable

For replacement requirements, also share clear photographs of the existing relay nameplate, front panel and rear terminal arrangement.

If the Siemens article number is unavailable, share the existing relay model and confirm the transformer winding arrangement, such as a three-winding transformer, autotransformer or transformer with four protected sides.

Siemens SIPROTEC 5 7UT86 Supplier and Exporter in India

ARP IMPEX supplies Siemens SIPROTEC 5 7UT86 Transformer Differential Protection Relays for utilities, EPC contractors, switchgear manufacturers, panel builders, power plants and industrial maintenance companies.

We handle enquiries for:

• Siemens SIPROTEC 5 7UT86 Protection Relays
• Three-winding transformer differential relays
• Four-side transformer protection relays
• Autotransformer differential protection relays
• Restricted earth-fault protection relays
• Transformer relays with IEC 61850
• Protection relays for utility substations
• Siemens transformer relay replacement
• Transformer protection-panel retrofit requirements
• Siemens 7UT86 price and availability
• Siemens transformer protection relay export requirements

The Siemens SIPROTEC 7UT86 price depends on the complete article number, transformer arrangement, measuring inputs, binary I/O, communication modules and required quantity.

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