Knowledge Center
Technical information, comparisons and sizing guides for choosing voltage regulators and transformers.
2-Year Insurance Cover: Burn-Out and Failure Protection for ONS Enerji Products
What does the 2-year insurance cover on ONS Enerji products mean? A payout can be claimed for burn-out and failure, with scope set by the policy terms.
Autotransformer vs Isolation Transformer: What Is the Difference?
Autotransformer vs isolation transformer: winding structure, galvanic isolation, safety, efficiency and cost. When to use which? Comparison table and guidance.
How to Calculate Voltage Regulator kVA: Step-by-Step Sizing Guide
How to calculate voltage regulator and transformer kVA. Watt-to-VA conversion, power factor, motor starting current and headroom, with worked examples.
Servo vs Static Voltage Regulator: Differences and Selection Guide
Differences between servo and static voltage regulators: speed, accuracy, maintenance and cost. Which one suits which load? Comparison table and selection guide.
What Is a Servo Voltage Regulator? How It Works and Where It Is Used
What is a servo voltage regulator, how does it work and which problems does it solve? Working principle, advantages, applications and selection criteria explained.
Technical Documents
Datasheets and user manuals (PDF)
Sizing tool
Enter the load power and see the kVA required with power factor and headroom applied.
Technical glossary
Short explanations of the terms you meet most often when choosing a regulator or transformer.
kVA kilovolt-ampere
The apparent power of a device. Because real power (kW) and power factor (cos φ) differ, regulators and transformers are sized in kVA, not watts.
Power factor cos φ
The ratio of real power drawn to apparent power. It is below 1 for inductive loads such as motors; 0.8 is the practical default when unknown.
Nominal voltage
The operating voltage a device is designed for. The grid is 50 Hz, and line voltage differs between single-phase and three-phase supplies.
Single-phase / three-phase
A supply with one phase plus neutral, or with three phases. The choice depends on the load and the grid connection.
Variac
An adjustable autotransformer whose brush slides along the winding to change output voltage continuously. It is the correcting element of a servo regulator.
Galvanic isolation
No direct electrical connection between input and output; energy passes only through the magnetic field. It provides safety and noise filtering.
Headroom margin
Safety margin added to the calculated power. Typically 20–25% is recommended for motor starting currents and future load growth.
Power quality
The overall view of disturbances such as voltage deviation, fluctuation, sags and harmonics. Regulators focus on voltage deviation.
Frequently Asked Questions
The most common questions about selecting regulators and transformers, custom manufacturing and the quotation process.
01What is a voltage regulator and what does it do?
A voltage regulator is an automatic protection device that keeps the voltage supplied to equipment close to its nominal value when mains voltage rises or drops. It protects machines, electronic boards and drives from failures and lifetime loss caused by voltage fluctuation.
02What is the difference between a servo and a static regulator?
A servo regulator corrects voltage steplessly and precisely with a servo-driven variac, but more slowly. A static regulator corrects in steps using electronic switches, very fast and with no moving parts. The choice depends on the load’s accuracy and speed needs.
03Are your products covered by insurance?
Yes. ONS Enerji products are covered by insurance for 2 years; in case of burn-out or failure, a payout can be claimed under the insurance cover. Scope, exclusions and the claim process follow the policy terms; please contact us for details.
04What is the difference between an autotransformer and an isolation transformer?
An autotransformer shares one winding between input and output; it is economical and efficient but gives no galvanic isolation. An isolation transformer has two electrically separate windings, providing safety and noise filtering.
Let’s define the right solution for your project
Share your load data and operating conditions; we will confirm kVA, voltage and protection needs together with our engineers.