Servolink
Servolink

Isolation Transformer

Overview

Isolation Transformer

A Clean, Separate Supply for Sensitive Machines

A Servolink isolation transformer gives your equipment its own supply, electrically separated from the mains, with a fresh neutral and earth reference at the machine.

Most of the problems that trip CNC controllers, medical machines and lab instruments are not about voltage level at all. They come from a high neutral-to-earth voltage, from noise and spikes that other machines push into the line, or from a shared neutral that carries the current of the whole building. A stabilizer cannot fix these, because it is connected to the same line.

An isolation transformer can: there is no direct electrical connection between its input and output windings, so the power reaches the load only through the magnetic core, and the noise stays behind.

SERVOLINK makes single phase and three phase isolation transformers — 1 to 100 kVA single phase, 5 to 500 kVA three phase — in our own factory in Ghaziabad.

Servolink double wound isolation transformer, front view
Single Phase
Servolink isolation transformer with electrostatic shield, side view
Enclosed Unit
The Problem

Why Your Machine Needs an Isolated Supply

In most buildings the neutral wire is shared by many loads and runs a long way back to the main transformer. Current flowing in this shared neutral raises its voltage above earth, so at the machine the neutral-to-earth voltage can climb to several volts or more, especially when the phases are unbalanced or the earthing is weak.

Modern machines treat this voltage as an error. CNC and VMC controllers stop with alarms, medical equipment shows noise on its readings, and lab instruments drift. Many machine suppliers specify a maximum neutral-to-earth voltage and will not honour warranty above it. On top of that, noise and harmonics from neighbouring machines travel along the same wiring and reach the controller.

None of this is fixed by correcting the voltage level. The machine needs its own clean supply, with a fresh neutral bonded to earth right at the machine — and that is what an isolation transformer creates.

The Benefit

What It Does for Your Machine

01
Brings Neutral-to-Earth Voltage DownThe output neutral is bonded to earth at the transformer, so the machine sees a neutral-to-earth voltage close to zero. Many CNC and medical machine makers ask for this below a few volts before they give warranty.
02
Blocks Noise and SpikesAn electrostatic shield between the windings stops high-frequency noise and spikes from passing through.
03
Protects PeopleThe output is not directly tied to the mains, which reduces the shock risk for operators and service staff.
04
Stops Problems SpreadingFaults, harmonics and noise created by one machine stay on its own transformer and do not disturb the others.
05
Voltage Change if NeededThe same transformer can also step the voltage up or down — for example 415 V to 230 V, or for imported machines that need 380 V or 220 V.
How It Works

How an Isolation Transformer Works

It has two separate copper windings on one CRGO core. The input (primary) winding creates a magnetic flux in the core, and that flux induces the output voltage in the secondary winding. There is no copper path between the two — only the magnetic path — so the output is a new, independent supply.

Between the two windings, a thin earthed copper sheet (electrostatic shield) catches the high-frequency noise that would otherwise pass from one winding to the other through their natural capacitance, and sends it to earth.

Applications

Where Is It Used?

01
CNC, VMC and Laser MachinesControllers and drives that give errors when neutral-to-earth voltage is high.
02
Hospitals and Diagnostic CentresMRI, CT, X-ray, ultrasound and ICU equipment.
03
Laboratories and R&DAnalytical instruments that need a clean reference.
04
Data Centres and ITServer rooms and UPS input or output side.
05
Printing MachinesImported presses with sensitive electronics.
06
Imported MachineryMachines built for a different voltage (380 V, 220 V, 110 V).
Compare

Isolation Transformer, Servo Stabilizer, or Both?

Your problemWhat solves it
Voltage goes too high or too lowServo stabilizer
High neutral-to-earth voltageIsolation transformer
Noise, spikes, machine errors with normal voltageIsolation transformer
Both voltage fluctuation and high N-E voltageServo stabilizer followed by isolation transformer

For sites with both problems, we supply the servo stabilizer and isolation transformer together, sized as one system.

Technical Data

Specification

BrandSERVOLINK
Product TypeDouble wound isolation transformer with electrostatic shield
PhaseSingle phase / three phase
Capacity1-100 kVA (single phase); 10-500 kVA (three phase)
Input Voltage230 V (single phase) / 415 V (three phase), or as required
Output Voltage230 V / 415 V, or as required (step up / step down on request)
Frequency50 Hz
CoreCRGO silicon steel
WindingCopper, made in-house
ShieldElectrostatic (copper foil) shield between windings, brought to earth terminal
Neutral-to-Earth Voltage at OutputLess than 2 V
Insulation ClassF-Class
CoolingAir cooled (dry type) / oil cooled on higher ratings
EnclosurePowder coated M.S. enclosure
InstallationIndoor
Questions

Frequently Asked Questions

Why does my CNC machine supplier ask for an isolation transformer?

Because CNC controllers are sensitive to neutral-to-earth voltage and line noise. An isolation transformer creates a new neutral bonded to earth right at the machine, which brings the neutral-to-earth voltage down to almost zero and keeps noise away from the controller.

Does an isolation transformer stabilize voltage?

No. If the input voltage drops 10%, the output also drops about 10%. For voltage fluctuation you need a servo stabilizer; use the isolation transformer after it.

What is the electrostatic shield?

A thin earthed copper sheet placed between the input and output windings. It catches high-frequency noise and spikes and sends them to earth, so they do not reach your equipment.

How do I size an isolation transformer?

Take the total kVA of the equipment it will feed and add margin for starting current. Share the machine nameplate details with us and we will suggest the right rating.

Does it need proper earthing?

Yes. The output neutral, the shield and the body must all be connected to a good earth pit. Without proper earthing, the transformer cannot bring the neutral-to-earth voltage down.

Is there any maintenance?

Very little. Keep it dust-free and ventilated, and get the terminals tightened and the earthing checked once a year.

Related

Related Products

Credentials

Our Certificates

Visit Us

How to Find Us

Mr. Hemant Rout (Proprietor)
S-26, SITE II, HARSHA COMPOUND, MOHAN NAGAR, GHAZIABAD U.P-201007

Get in Touch

At Servolink, we are committed to providing you with the best isolation transformer solutions. Whether you need assistance in selecting the right transformer for your needs or require support with your existing system, our team is here to help. Contact us today to learn more about our products and services.

Experience the reliability and efficiency of Servolink Isolation Transformers and protect your valuable electrical equipment from voltage fluctuations and electrical noise. Join our growing list of satisfied customers who trust Servolink for their isolation transformer needs.

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