Three Phase Air Cooled Servo Voltage Stabilizer Manufacturer in India

Purevolt India manufactures three phase air cooled servo voltage stabilizers from 10 KVA to 200 KVA in balanced and unbalanced configurations. Stable 400V AC output within ±1%, 96% efficiency. High grade copper windings. ISO 9001 certified, NABL tested, SONCAP approved. Trusted in 60+ countries since 1995.

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Three Phase Air Cooled Servo Voltage Stabilizer - Purevolt India

30+Years Manufacturing

60+Countries Exported

10–200 KVAThree Phase Range

ISO 9001NABL · SONCAP

±1%Output Stability

Purevolt India manufactures three phase air cooled servo voltage stabilizers from 10 KVA to 200 KVA in balanced and unbalanced configurations. Stepless three phase voltage correction with output stability within ±1% and 96% efficiency. Suitable for CNC machines, injection moulding, packaging, textile, and all industrial three phase applications up to 200 KVA. ISO 9001 certified, NABL tested, SONCAP approved.

What It Is

Three Phase Air Cooled Servo Voltage Stabilizer

Your CNC machine, injection moulding press, packaging line, or textile loom runs on three phase supply. When that supply swings between 350V and 450V through the working day, the machines do not run as they were designed to. A three phase air cooled servo voltage stabilizer continuously corrects all three phases to a stable 400V AC output within plus or minus 1 percent before the voltage reaches your machinery.

Purevolt manufactures three phase air cooled servo stabilizers from 10 KVA to 200 KVA in balanced and unbalanced configurations. Built using high grade copper windings and advanced solid-state control circuits. Every unit is made to order at our Okhla, Delhi facility to match your exact load, input voltage range, and site conditions.

Why Install

Why Your Factory Needs a Three Phase Servo Stabilizer

Voltage instability on three phase supply damages machines, wastes energy, and causes downtime. The cost of not installing a stabilizer adds up faster than most plant managers realise.

Industrial Three Phase Supply Fluctuates Constantly

LT three phase supply at industrial premises steps down from 11kV through a distribution transformer. Load changes in your feeder zone, neighbouring factory startups, and utility load balancing all cause fluctuations at your main switchboard. Your machines were not designed to tolerate this and your utility cannot fix it in real time.

Machines Fail at Wrong Three Phase Voltage

CNC machine controllers, servo drives, injection moulding control panels, and packaging machine PLCs are all designed for operation within plus or minus 5 percent of rated voltage. Sustained overvoltage burns motor windings. Sustained undervoltage causes overcurrent and motor overheating. Both cause production stoppages and expensive repairs that could have been avoided.

One Stabilizer Protects Your Entire Plant

A single three phase servo stabilizer at the main intake protects all connected equipment in your factory. It is simpler and more cost-effective than installing individual protection on every machine. One unit, one warranty, one point of contact for your entire power protection requirement at the plant level.

Stabilizers Pay for Themselves Quickly

A Purevolt three phase servo stabilizer typically recovers its cost within 6 to 12 months through reduced maintenance, fewer motor rewinds, lower MDI charges from optimised current draw, and elimination of production losses from voltage-related stoppages. The math almost always favours the stabilizer.

How It Works

How a Three Phase Air Cooled Servo Stabilizer Works

Purevolt three phase air cooled servo stabilizers use solid-state electronic control and AC synchronous servo motors to continuously monitor and correct all three phases in real time.

PCB Monitors All Three Phases

The solid-state control card continuously samples all three incoming phase voltages and compares each to the 400V reference. This monitoring runs many times per second without interruption at any load level.

Error Signal Drives the Servo Motor

Any deviation from the reference generates an error signal. This drives the AC synchronous servo motor in the appropriate direction. Motor speed is proportional to the magnitude of the error, so large deviations are corrected faster than small ones.

Dimmerstat Adjusts Tap Position

The servo motor moves the dimmerstat arm to change the voltage tap. Correction is stepless, continuous, and proportional. This is fundamentally different from relay stabilizers that switch in fixed steps, leaving the output oscillating around the target voltage rather than holding it steady.

Stable 400V AC Delivered to the Load

Corrected voltage passes through the series buck-boost transformer stage and reaches your machinery as stable three phase 400V AC within plus or minus 1 percent. Forced air cooling from exhaust fans and louvers keeps the unit at safe operating temperature throughout continuous operation.

Technical Specifications

Three Phase Air Cooled Servo Stabilizer Specifications

Specification	Details
Capacity Range	10 KVA to 200 KVA
Phase	Three Phase
Input Voltage Range	300V to 460V AC (line to line); custom ranges available
Output Voltage	400V AC ±1%
Frequency	50 Hz (60 Hz available for export)
Correction Speed	25 to 30V per second
Cooling Type	Air Cooled (forced air with exhaust fans and louvers)
Efficiency	96% and above
Construction	Balanced Type / Unbalanced Type
Winding Material	High grade copper windings and strips
Certifications	ISO 9001:2008, NABL, SONCAP (Bureau Veritas / SGS / Intertek)
Warranty	1 year standard; extended warranty available
Customisation	Input/output voltage, KVA, balanced or unbalanced, enclosure all customisable on request

Salient Features

Features of Purevolt Three Phase Air Cooled Stabilizers

Stepless three phase voltage correction using AC synchronous servo motors and dimmerstats
Output voltage stability within ±1%, far tighter than relay-type stabilizers
Efficiency of 96% and above at all load conditions
Handles input voltage from 300V to 460V AC without interrupting output
Correction speed of 25 to 30 volts per second for fast response to sudden dips
Available in balanced and unbalanced type to suit your load distribution
High grade copper windings for low resistive losses and long service life
Suitable for all types of power factor loads
Over and under voltage protection with automatic cut-off
Digital voltmeter display for input and output voltage monitoring
50 Hz standard; 60 Hz available for export orders
ISO 9001 certified manufacturing, NABL tested, SONCAP certified for export

Balanced vs Unbalanced

Balanced Type vs Unbalanced Type: Which One Do You Need?

This is the most common question when ordering three phase stabilizers. The answer depends on your site’s phase voltage distribution.

Balanced Type

Single servo motor corrects all three phases together
Simpler construction, lower cost
Suitable when all three phases fluctuate together
Used where supply is reasonably balanced
Good for most standard industrial sites
Compact and lighter design

Unbalanced Type
Three separate servo motors, one per phase
Each phase corrected independently
Required when phase voltages differ significantly
Recommended for mixed single and three phase loads
Better for CNC machines with unbalanced loading
Preferred for hospitals and research facilities

Industries Served

Where Three Phase Air Cooled Stabilizers Are Used

Any three phase load below 200 KVA that operates in a moderate indoor environment and needs steady voltage throughout the working day.

CNC Machines

Injection Moulding

Packaging Machines

Hospitals

Textile Looms

Printing Machines

Cold Storage

Pharma Units

Food Processing

Hotels & Resorts

Schools & Colleges

Telecom

Oil Refineries

Data Centres

Laboratories

Lifts & Elevators

How to Select

How to Choose the Right Three Phase Servo Stabilizer

Five questions that determine the correct unit for your plant. Answer these and send the details to our team for a quote within 24 hours.

What is your total connected three phase load?List all three phase equipment and their rated power. Sum up the total KVA or KW. Add 20 to 25 percent headroom for startup surges and future equipment additions.

What is your site’s actual input voltage range?Measure the supply voltage at your switchboard at different times of day and on different days. Note the minimum and maximum readings on all three phases. Do not estimate this from your tariff card.

Are your three phase voltages balanced or unbalanced?If the three phase voltages at your site differ from each other by more than 5 percent consistently, you need an unbalanced type stabilizer with independent correction per phase.

What is the ambient temperature at your installation site?If site temperature regularly exceeds 45 degrees, or if the unit will be outdoors, consider oil cooled regardless of KVA rating. Air cooled works well in moderate indoor environments.

Is your supply 50 Hz or 60 Hz?Standard Indian supply is 50 Hz. If the stabilizer is for equipment rated at 60 Hz or for export to a 60 Hz country, specify this when ordering. Purevolt manufactures both.

Global Reach

Countries We Export Three Phase Air Cooled Stabilizers To

ISO 9001 certified, NABL tested, SONCAP approved. Trusted in 60 plus countries since 1995.

FAQ

Frequently Asked Questions

What is a three phase air cooled servo voltage stabilizer?

A three phase air cooled servo voltage stabilizer is an automatic voltage controller that uses servo motors and variable auto transformers to continuously correct three phase supply voltage to a stable 400V AC output within plus or minus 1 percent. Forced air cooling from exhaust fans and louvers keeps the unit at a safe operating temperature. It is available in balanced and unbalanced configurations from 10 KVA to 200 KVA.

What is the difference between balanced and unbalanced type three phase stabilizers?

A balanced type uses a single servo motor to correct all three phases together. It cannot correct individual phase voltages independently. An unbalanced type uses three separate servo motors, one per phase, and corrects each phase independently. Unbalanced type is recommended when phase voltages at your site differ significantly from each other.

What input voltage range does the three phase air cooled stabilizer handle?

The standard three phase air cooled servo stabilizer handles input voltage from 300V to 460V AC line to line and delivers stable 400V AC output within plus or minus 1 percent. Custom input ranges are available for sites where the supply falls outside this window. Share your measured voltage readings with our team for confirmation.

What is the maximum KVA in three phase air cooled?

Purevolt manufactures three phase air cooled servo stabilizers up to 200 KVA. For capacities above 200 KVA, oil cooled three phase units are recommended. Oil cooling handles the greater heat generated at these ratings more reliably, especially in industrial environments with high ambient temperatures.

What is the correction speed of Purevolt three phase air cooled stabilizers?

Purevolt three phase air cooled servo stabilizers correct at 25 to 30 volts per second. This speed handles sudden load switching and voltage dips common in industrial environments without the output going outside the regulated band.

Which industries use three phase air cooled servo stabilizers most?

The most common applications are CNC machine shops, injection moulding units, packaging lines, printing machines, textile looms, hospitals, hotels, and any industrial or commercial premise that runs three phase equipment below 200 KVA in a moderate indoor environment.