Transformers & Substations > AC Voltage Stabilizers
TND Single-Phase Automatic Voltage Regulator
The TND series delivers precision AC voltage regulation for single-phase power lines from 1KVA up to 60KVA. Built around a contact-type autotransformer regulator, a servo-motor drive, and an automatic control circuit, it continuously corrects unstable grid voltage and holds output steady at the rated value — protecting homes, offices, laboratories, and light industrial loads from voltage swings. Available on the compact TND3 platform (up to 3KVA) and the extended-range TND5 platform (5-60KVA), with configurable input voltage windows and OEM/ODM options for enclosure, output configuration, and private-label branding.





Key Features
Six core capabilities that keep the TND series delivering stable, protected power across fluctuating grid conditions.
Wide Input Voltage Range
Corrects input fluctuations from as low as 90V up to 330V (model dependent) back to a stable 220V output, protecting sensitive equipment on weak or unstable grids.
High Regulation Precision
±3% output voltage precision maintained automatically through servo-motor-driven autotransformer adjustment, even as connected loads change.
Fast Correction Response
Responds within ≤1.5 seconds whenever external voltage swings more than 10% from rated value, minimizing disruption to connected equipment.
Five-Way Protection
Built-in under-voltage, over-voltage, short-circuit, and over-current protection (5× rated current, ~1 second) safeguards both the regulator and downstream loads.
Intelligent LCD Display
Real-time input voltage, output voltage, and load ratio shown on an LCD panel for continuous, at-a-glance monitoring.
Heavy-Duty Copper Winding
Dual-coil, full-copper winding construction increases power handling capacity and improves thermal stability under sustained load.
OEM & ODM Capabilities
Flexible OEM and ODM support covering product configuration, specifications, labeling, branding, packaging and project-specific customization requirements.
OEM Production to Specification
Production can follow approved customer specifications, drawings and project requirements for the exact cable model being ordered.
Custom Finished Length
Cable or patch-cord length can be defined by the approved production drawing, with model-specific finished-length tolerances.
Jacket & Construction Options
PVC, PE or LSZH jacket options can be selected where supported by the applicable product configuration and project requirement.
Custom Printing & Marking
Product identification and cable marking can be defined according to the approved specification and production requirements.
Custom Labeling
Product labels can be included according to the approved drawing, project identification and packaging requirements.
Custom Packaging
Poly-bag and carton packaging can be configured according to finished length, quantity and shipment requirements.
Technical Specifications
Full electrical, protection, and dimensional data across the complete TND3 / TND5 model range.
| Regulator Type | Contact-type Automatic AC Voltage Regulator (Servo-motor Driven) |
|---|---|
| Series | TND3 (1-3KVA) / TND5 (5-60KVA) |
| Rated Output Voltage | 220V, single-phase |
| Regulation Precision | ±3% |
| Frequency | 50/60Hz |
| Applicable Load | Any load type, no additional waveform distortion |
| Response Speed | ≤1.5s when external voltage change exceeds 10% |
| Installation Conditions | Indoor use, altitude ≤3500m, -15°C to 40°C |
| Metric | Value | Notes |
|---|---|---|
| Capacity Range | 1-60KVA | TND3 / TND5 |
| Response Speed | ≤1.5s | >10% voltage change |
| Protection Rating | IP20 | Indoor installation |
| Cooling Method | Self-cooling / Air-cooling | Model dependent |
| Model | Capacity | Input Voltage | Rated Current | Product Dimensions (L×W×H mm) | Net Weight | Packing Weight |
|---|---|---|---|---|---|---|
| TND3-1000VA | 1KVA | 140-260V | 4.5A | 215×205×170 | ~5kg | ~5.5kg |
| TND3-1500VA | 1.5KVA | 140-260V | 6.8A | 215×205×170 | ~5.5kg | ~6kg |
| TND3-2000VA | 2KVA | 140-260V | 9A | 275×240×205 | ~7.5kg | ~8kg |
| TND3-3KVA (Low-Voltage) | 3KVA | 110-260V | 13.5A | 305×240×240 | ~10.5kg | ~11kg |
| TND3-3KVA (Standard) | 3KVA | 140-260V | 13.5A | — | — | — |
| TND5-5KVA (Low-Voltage) | 5KVA | 90-250V | 22.7A | 330×250×265 | ~16kg | ~17.5kg |
| TND5-5KVA (Standard) | 5KVA | 150-250V | 22.7A | 330×250×265 | ~13.5kg | ~14.5kg |
| TND5-10KVA (Low-Voltage) | 10KVA | 110-260V | 45.4A | 340×315×540 | ~38kg | ~40kg |
| TND5-10KVA (Standard) | 10KVA | 150-250V | 45.4A | 345×320×540 | ~32kg | ~36kg |
| TND5-15KVA (Low-Voltage) | 15KVA | 110-330V | 68.1A | 400×350×610 | ~51kg | ~57kg |
| TND5-15KVA (Standard) | 15KVA | 150-300V | 68.1A | 405×355×610 | ~45kg | ~50kg |
| TND5-20KVA (Low-Voltage) | 20KVA | 110-300V | 90.9A | 405×355×610 | ~55kg | ~60kg |
| TND5-20KVA (Standard) | 20KVA | 110-330V | 90.9A | 400×350×610 | ~48kg | ~53kg |
| TND5-30KVA (Low-Voltage) | 30KVA | 110-330V | 136.3A | 400×350×780 | ~70kg | ~77kg |
| TND5-30KVA (Standard) | 30KVA | 150-300V | 136.3A | 400×350×780 | ~62kg | ~69kg |
| TND5-40KVA (Low-Voltage) | 40KVA | 150-300V | 181.8A | 550×450×1040 | ~119kg | ~131kg |
| TND5-40KVA (Standard) | 40KVA | 110-330V | 181.8A | 350×400×780 | ~68kg | ~75kg |
| TND5-50KVA (Low-Voltage) | 50KVA | 110-330V | 227A | 550×450×1040 | ~132.5kg | ~141kg |
| TND5-60KVA (Low-Voltage) | 60KVA | 110-330V | 271A | 550×450×1040 | ~147kg | ~156kg |
Construction & Configuration
Inside the TND regulator: how the contact-type autotransformer, servo drive, and control electronics work together to hold voltage steady.
Contact-Type Autotransformer Coil
The core component that adjusts output voltage as a moving carbon brush changes contact position along the copper winding.
Servo Motor Drive Assembly
A precision servo motor repositions the carbon brush in response to control signals, correcting voltage deviations in real time.
Automatic Control Circuit
Continuously samples input and output voltage and dispatches correction signals to the servo motor to hold the rated output.
Front & Rear Dual Carbon Brush Design
Front and rear carbon brushes work together for more precise output regulation and improved stability under changing load.
Intelligent LCD Display Panel
Shows real-time input voltage, output voltage, and load ratio on the front panel for continuous monitoring.
Protective Circuit Breaker & Enclosure
Steel enclosure with an integrated ON/OFF circuit breaker for safe manual disconnect and overload protection.
Standards & Test Documentation
Performance, safety, and documentation support behind every TND regulator.
Voltage Regulation Performance
Maintains ±3% output precision with correction response ≤1.5 seconds for external voltage swings greater than 10%, and 5× rated current over-current tolerance for approximately 1 second.
Dielectric Withstand & Protection
Rated to withstand a 1500V power-frequency sine wave for 1 minute without puncture or flashover; IP20 enclosure protection for indoor installation.
OEM/ODM Technical Support
Full technical datasheets, dimensional drawings, and test reports available on request to support OEM/ODM integration and procurement evaluation.
Need a Custom Voltage Regulation Solution?
Share your load profile, input voltage range, and enclosure requirements — our engineering team will configure the right TND regulator for your project, from single units to bulk OEM/ODM orders.