Three Phase Neutral Grounding/earthing Transformer direct supply 15kV-36kV

Attributes Description Documentation Resource Library

Key attributes

Brand	ROCKWILL
Model NO.	Three Phase Neutral Grounding/earthing Transformer direct supply 15kV-36kV
Rated voltage	36kV
Rated normal current	3000A
Rated frequency	50/60Hz
Series	JDS

Description

Rockwill three-phase oil-immersed Z-type earthing transformers are designed for medium-voltage power systems requiring a reliable artificial neutral point. Featuring a fully sealed oil-immersed structure with optimized zigzag (ZN/ZNyn) winding, these transformers provide stable neutral grounding for ungrounded or low-current grounded systems from 15 kV to 36 kV.

They effectively suppress arc grounding overvoltage, limit ground fault currents, and enhance grid stability. Manufactured in compliance with IEC standards, these units are suitable for distribution networks, industrial facilities, and utility substations.

Key Features

Medium-Voltage Neutral Grounding :Provides an artificial neutral point for ungrounded or delta-connected systems from 15 kV to 36 kV, enabling connection of arc suppression coils or neutral grounding resistors.
Optimized Z-Type Winding:Zigzag (ZN/ZNyn) winding configuration delivers low zero-sequence impedance, ensuring efficient fault current path and sensitive relay protection.
Oil-Immersed Fully Sealed Construction :Durable sealed tank design with mineral oil insulation ensures long service life, strong overload capacity, and maintenance-free outdoor operation.
Flexible Cooling Options:Available with ONAN, ONAF, AN, or AF cooling systems to match application load profiles and ambient conditions.
Customizable Secondary Winding:Optional 0.4 kV auxiliary winding enables dual use as station service transformer, supplying local LV loads.

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Technical Parameters

Parameter	Value
Highest voltage for equipment (Um)	17.5 / 36 kV
Rated frequency	50 / 60 Hz
Number of phases	Three
Connection group	ZN (zigzag) / ZNyn11
Rated neutral current	Up to 3000 A (customizable)
Rated short-time duration	10 s / 30 s / 60 s (customizable)
Zero-sequence impedance (Zo)	Per project specification (tolerance ≤ ±10 %)
Cooling method	ONAN / ONAF / AN / AF
Insulation medium	Mineral oil
Auxiliary winding	Optional 0.4 kV
Ambient temperature	–25 °C to +40 °C
Installation	Indoor or outdoor
Enclosure options	IP-rated cabinet; optional CT, VT, or isolation switch

Environmental Conditions

Item	Value
Max ambient air temperature	+40°C
Max 24h average ambient air temperature	+35°C
Min ambient air temperature	-25°C
Altitude	≤ 1000 m
Max relative humidity（24h average）	≤ 95%
Max relative humidity（1 month average）	≤ 90%
Max water vapor pressure（24h average）	2.2 kPa
Max water vapor pressure（1 month average）	1.8 kPa
Solar radiation	≤ 1000 W/m²
Pollution level	II

Applications

Medium-voltage distribution network neutral grounding (15 kV – 36 kV)
Wind farm and photovoltaic power station grid connection
Railway traction power supply systems
Industrial and mining enterprise power distribution
Regional substation grounding protection projects
Urban power grid upgrading and renovation

Standards

IEC 60076-6 — Power transformers – Part 6: Reactors (grounding transformer requirements)
IEC 60076-1 — Power transformers (general)
IEC 60071-1 — Insulation coordination
ISO 9001 — Quality management system

Solutions for Grounding/earthing Transformer

Intelligent Maintenance Services and Sustainable Solutions for Z-Type Grounding Transformers

Intelligent Maintenance Services and Sustainable Solutions for Z-Type Grounding TransformersZ-type grounding transformers are critical for stabilizing ungrounded or delta-connected power systems by providing a low-impedance path for zero-sequence currents during faults. Integrating intelligent maintenance and sustainability practices enhances their reliability while minimizing environmental impact. Below is a structured analysis of advanced solutions:I. Intelligent Maintenance Services Real-Time

Rockwill

Documentation Resource Library Grounding/earthing Transformer

Public.

Rockwill Electric Group Profile

Brochure

English

PDF

$2592.00

Pricing calculator

Model

JDS/36/3000

PDF

Rockwill Electric Group Profile

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