Product Overview

The HET 50kVA exciter transformer delivers precision testing with dual-voltage outputs (5kV/2.5kV) and ultra-low impedance (<5%). Designed with ONAN cooling and advanced electrostatic shielding, it complies with IEC 60076-11 standards for demanding industrial applications.

Electrical Specifications

Key Features

Dual-Voltage Operation

• Independent winding taps for each voltage range

• Precision voltage ratio (±0.5% accuracy)

• No-load tap changer for safe switching

Thermal Performance

• ONAN cooling with 25# transformer oil

• Continuous operation at full rated capacity

• Winding temperature rise ≤65K

Protection Systems

1. Overvoltage Protection

• Piezoresistors on all HV outputs

• Zinc oxide arresters (15kA rating per IEC 60099-4)

• Dual grounding points with 10mm² copper straps

2. Insulation Control

• 5kV corona-free fiberglass bushings

• Electrostatic shielding between HV/LV windings

• Isovolumetric capacitance cores for stable voltage distribution

Mechanical Design

Enclosure Features

• 12-gauge steel housing with corrosion-resistant coating

• Wheel-mounted (4× industrial casters with brakes)

• Shell-type oil tank with 55L conservator

Terminal Configuration

• LV terminals: Porcelain bushings

• HV terminals: Fiberglass-reinforced epoxy bushings

• All bushings feature dual corona rings

Winding Technology

• Cylinder-type windings with balanced capacitance

• Electrostatic compensation shields

• Inter-turn insulation (1.5mm Nomex® layers)

• Compound insulation tubes for partial discharge control

Installation & Maintenance

Commissioning Requirements

• Minimum 1m clearance from grounded surfaces

• Initial oil BDV ≥45kV (2.5mm gap)

• Pre-operation IR ≥8,000MΩ

Service Schedule

• Monthly: Bushing contamination inspection

• Quarterly: Oil dielectric strength testing

• Annual: Complete winding resistance test

Typical Applications

• Power cable withstand testing

• Circuit breaker contact resistance tests

• Rotating machine insulation diagnostics

• Transformer factory acceptance tests