1MVA 34.5kV Pad-Mounted Zig-Zag Grounding Transformer NEMA 4X 316 Stainless

This 1 MVA pad-mounted zig-zag grounding transformer is configured for 34500Y/19920V, 60Hz medium-voltage systems in outdoor utility, renewable-energy, and industrial power applications. Designed in accordance with applicable ANSI/IEEE C57.12.00 and CSA requirements, it provides a 120A continuous neutral-current rating and a short-time current capability of 1000A for 10 seconds.

Built with a 316 stainless-steel tank, cabinet, and base platform in a NEMA 4X configuration, the unit offers enhanced corrosion resistance for demanding outdoor environments. Its 200kV BIL insulation level, 900A deadbreak elbow connections, separately installed 36kV surge arresters, and four-channel winding-and-core temperature monitoring support dependable operation and comprehensive condition monitoring.

A zig-zag grounding transformer establishes an accessible neutral point for a medium-voltage system where a suitable neutral is not otherwise available. It provides a controlled path for zero-sequence and ground-fault current, allowing protective devices to detect and isolate ground faults while helping stabilize the system phase-to-ground voltage.

• 316 Stainless Steel Enclosure & Tank Construction

  Built with premium 316 stainless steel for the tank, cabinet, and base platform, offering superior corrosion resistance for harsh coastal, industrial, or high-humidity outdoor installations.

• 1000A / 10s Short-Time Current Capability

  Designed to withstand grounding fault current of up to 1000A for 10 seconds, supporting reliable operation during short-duration system ground-fault conditions.

• 200kV BIL and 900A Deadbreak Connection System

  Equipped with 38kV class 200kV BIL standoff bushings, 900A deadbreak elbow connectors, and integrated 36kV surge arresters for reliable high-voltage dead-front termination.

• Four-Channel Thermal Monitoring

  Four internal temperature sensors—one on each coil and one on the core—are connected to a Qualitrol TR6000 temperature indicator for continuous monitoring of key internal thermal conditions.

• Qualitrol Protection and Instrumentation Package

  Outfitted with top-tier Qualitrol accessories including a sudden pressure relay (900-FLA-Q-060-STD), pressure relief valve (LPRD), oil level gauge, and pressure indicator with alarm contacts.

   

     

• Oil Level Indicator (Qualitrol LLG042) — Displays the insulating-oil level with high- and low-level alarm contacts for continuous fluid monitoring.
• Liquid Temperature Gauge (Qualitrol TR6000) — Provides clear liquid-temperature indication with high- and low-temperature contacts for alarm and control functions.
• Pressure/Vacuum Indicator — Displays the sealed tank’s internal pressure and vacuum condition with high- and low-pressure contacts.
• Pressure Relief Device (Qualitrol LPRD) — Automatically releases excessive internal pressure to help protect the sealed transformer tank.
• Rapid Pressure Rise Relay (Qualitrol 900-FLA-Q-060-STD) — Detects sudden internal pressure increases and provides a signal to the transformer protection system.
• Winding and Core Temperature Monitoring — Uses four internal sensors, one on each winding coil and one on the core, to monitor critical thermal conditions.
• H0 Neutral Bushing — Provides the neutral and grounding connection through a live-front bushing with a NEMA four-hole spade.
• 900A Deadbreak HV Connections — Provide shielded separable cable connections for the three high-voltage phases.
• 36kV Surge Arresters — One arrester per phase provides additional protection against incoming overvoltage surges.
• Two-Position Load Break Switch — A 200A, 38kV switch provides convenient manual switching and circuit isolation in the HV compartment.
• Oil Drain and Sampling Valve — Supports efficient oil draining and representative insulating-oil sampling.
• NEMA Grounding Bar — Provides a robust protective-grounding connection securely bonded to the 316 stainless-steel tank.

1. Winley Electric three-phase transformers are UL/cUL Listed under File No. E536138, with ratings from 45 kVA through 10 MVA. They are designed and manufactured to meet applicable ANSI/IEEE, CSA, NEMA, and DOE 2016 requirements.
2. With extensive experience in North American utility, industrial, and commercial projects, Winley Electric can deliver cost-effective customized solutions based on your specific project requirements.
3. With a strong supply chain and experienced production team, Winley Electric support fast delivery with a 4–6 weeks production time after technical approval to help keep your project on schedule.

A: Winley delivers standard three-phase pad-mounted transformers with a 4–6 weeks production time after technical approval. We provide a detailed production schedule and real-time manufacturing photos to help track progress.

A: We offer a flexible MOQ of just 1 unit. Complete inquiries are quoted within 1–2 days with 24/7 support. Leveraging our extensive North American project experience, we ensure highly cost-effective and reliable solutions.

A: Yes, We accept OEM and ODM. Winley three-phase pad-mounted transformers are available in standard ratings from 45–5000kVA (and maximum capability up to 10MVA), with HV systems up to 36 kV. We can customize electrical parameters, structure, fluid, protection, switches, gauges, tank and paint according to customer drawings, with the capability to integrate components from brands like Qualitrol, Eaton Cooper, and MR.

A: Yes. Our full range of products are UL/cUL-certified under UL File No. E536138, designed strictly in compliance with ANSI/IEEE, CSA, DOE, and NEMA requirements to meet grid connection and regulatory standards.

A: We deliver a complete compliance package: approval drawings, datasheets, routine test reports, UL/cUL certs, DOE 2016 docs, and operation manuals. We also back your project with lifetime documentation support.

A: Winley ensures quality through 4 annual unannounced UL audits and strict ISO 9001 process management with dedicated QC oversight. Prior to delivery, every unit undergoes comprehensive routine testing, including Winding Resistance, Turns Ratio, Polarity and Phase Relation, and No-Load Loss and Excitation Current tests. We also fully support Factory Acceptance Testing (FAT) and third-party inspections (SGS).

A: 24 months from B/L. During the warranty period, If there are any accessory problems, just provide photos of damaged accessory, then we will provide free service. According to the number of products, we will provide easily damaged accessories for free. We can also provide technical support if you need.