Transformers & Substations
QSG Three-Phase Dry-Type Isolation Transformer
Imported machinery doesn’t automatically speak your grid’s language. A production line built for 200V factory power, a lab instrument built for 100V, an assembly system built around a different frequency — none of it runs safely off a straight local supply. The QSG series exists to bridge that gap: it steps your incoming three-phase voltage up or down to whatever the imported equipment’s nameplate actually calls for, while galvanically isolating that equipment from the mains so a ground fault on one side doesn’t propagate to the other. Being dry-type, it runs without oil, which matters indoors, in tunnels, in laboratories, and around photovoltaic installations where an oil-filled unit’s fire load and disposal requirements simply don’t fit. Optional control-cabinet accessories — breakers, contactors, voltmeters, ammeters, wattmeters, indicator lights — turn a bare transformer into a complete, monitored power supply, and output voltage can be built to the imported equipment’s exact spec rather than the nearest standard tap. The range spans a compact 3KVA bench unit to custom-built 500KVA industrial systems.
Key Features
Built to Match Imported Equipment, Not Just Step Voltage
The QSG series is engineered around voltage-matching and electrical isolation for imported machinery, rather than general-purpose power distribution.
Custom Voltage & Frequency Matching
Output voltage built to the imported equipment's exact nameplate spec, with 50/60Hz frequency support.
Galvanic Isolation
Separates the connected equipment from the mains supply, containing ground faults on either side rather than letting them cross over.
Dry-Type, Oil-Free Construction
No oil to leak, ventilate, or dispose of — suited to indoor sites, tunnels, laboratories, and photovoltaic installations.
Pure Sine Wave Output
No additional waveform distortion introduced, delivering power comparable to clean mains supply.
2000V / 1-Minute Dielectric Withstand
Power-frequency sine wave voltage of 2000V held for one minute with no breakdown or flashover.
3-500KVA Capacity Range
Standard builds up to 200KVA, with 300KVA and above available as custom-engineered units.
OEM & ODM Capabilities
Built-to-Order for B2B and System Integrators
Voltage, capacity, and control-cabinet accessories are configured around the specific imported equipment being powered.
Configurable Capacity
Standard range 3-200KVA, with 300-500KVA and above available as custom-engineered builds.
Input/Output Voltage Customization
Output voltage matched to the exact nameplate requirement of the equipment being powered, beyond the standard 380V-to-220V configuration.
Control Cabinet Accessories
Breakers, contactors, voltmeters, ammeters, wattmeters, and indicator lights added to build a complete monitored power supply.
Enclosure & Branding Customization
Cabinet finish, mobility (casters), and labeling configurable for private-label and distributor branding.
Application-Specific Configuration
Sized and configured for import/export equipment, tunnel and site power, laboratory use, or photovoltaic installations.
Small-to-Large Batch Production
From single-unit engineering builds to volume production for distributors and EPC contractors.
Technical Specifications
Core electrical parameters are shared across the QSG series; capacity, current rating, and dimensions scale by model.
| Product Name | Three-Phase Dry-Type Isolation Transformer |
|---|---|
| Input Voltage | 380V |
| Output Voltage | 220V, three-phase four-wire + ground |
| Frequency | 50/60Hz |
| Applicable Load | Any load type |
| Waveform Distortion | None additional |
| Dielectric Strength | 2000V power-frequency sine wave, 1 minute, no breakdown/flashover |
| Protection Rating | IP20 |
| Cooling Method | Self-cooling / air-cooling |
| Capacity Range | 3-500KVA (300KVA and above custom-built) |
| Voltage | 380V → 220V |
|---|---|
| Frequency | 50/60Hz |
| Capacity | 3-500KVA |
| Protection | IP20 |
| Model | Rated Capacity | Rated Current | Dimensions (W×D×H) |
|---|---|---|---|
| QSG-3KVA | 3000VA | 7.9A | 390×300×330mm |
| QSG-5KVA | 5000VA | 13.1A | 450×300×390mm |
| QSG-10KVA | 10KVA | 26.24A | 505×350×420mm |
| QSG-15KVA | 15KVA | 39.4A | 540×380×420mm |
| QSG-20KVA | 20KVA | 52.4A | 570×420×460mm |
| QSG-25KVA | 25KVA | 65.7A | 570×420×460mm |
| QSG-30KVA | 30KVA | 78.9A | 640×420×460mm |
| QSG-40KVA | 40KVA | 104.9A | 640×420×460mm |
| QSG-50KVA | 50KVA | 131.5A | 580×460×450mm |
| QSG-60KVA | 60KVA | 157A | 580×460×500mm |
| QSG-80KVA | 80KVA | 210A | 580×460×500mm |
| QSG-100KVA | 100KVA | 263A | 730×480×650mm |
| QSG-150KVA | 150KVA | 394A | 800×500×700mm |
| QSG-200KVA | 200KVA | 526A | 900×500×800mm |
| QSG-300KVA | 300KVA | 787A | Custom-built |
| QSG-400KVA | 400KVA | 1052A | Custom-built |
| QSG-500KVA | 500KVA | 1315A | Custom-built |
Construction & Configuration
A dry-type core and coil assembly sits inside a mobile steel cabinet with a digital parameter display and optional control accessories.
Dry-Type Core & Coil
High-temperature-resistant windings and quality silicon steel core, requiring no oil fill or oil maintenance.
Surge & Lightning Protection
Built-in protection against lightning-induced surges on the incoming supply.
Digital Parameter Display
Front-panel screen reads live input and output voltage, so voltage matching stays visible during operation.
Ventilated Steel Enclosure
Perforated side panel supports natural convection or fan-assisted cooling for the dry-type core.
Mobile Cabinet on Casters
Smaller-capacity models are mounted on caster wheels for repositioning around a workshop or lab.
Configurable Control Cabinet
Optional breakers, contactors, and metering instruments combine with the transformer to form a complete monitored power supply.
Standards & Test Documentation
Dielectric withstand testing and protection rating are confirmed on every unit; further compliance documentation is available for procurement review.
Dielectric Withstand Test
Every unit is tested at 2000V power-frequency sine wave voltage for one minute with no breakdown or flashover.
IP20
Enclosure rated IP20, suited to indoor installation environments free of significant dust or moisture ingress.
Datasheets & Installation Guidance
Full parameter sheets and installation-condition documentation available on request for procurement and engineering review.
Powering Imported Equipment on Local Voltage?
Tell us the equipment's nameplate voltage and frequency, plus your local supply — we'll configure a QSG unit or another series to match.