Servo Controlled · Oil Cooled · Heavy Industrial Grade

150 kVA 3-Phase Servo Voltage Stabilizer

Built for multi-machine CNC banks, large injection molding lines, textile mills, and heavy industrial automation floors — delivering ±1% output accuracy and continuous 120 kW active load capacity under fluctuating grid conditions.

150 kVA120 kW Active Load

98.5%Efficiency

±1%Output Accuracy

ONANOil Cooling

<30msResponse Time

IP54Enclosure Rating

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150 kVA Three-Phase Oil Cooled Servo Voltage Stabilizer — VoltaPex Power

Technical Specifications

Complete parameter sheet for the 150 kVA three-phase oil cooled servo voltage stabilizer, sized for heavier industrial duty cycles than the 100 kVA range.

150 kVA Servo Voltage Stabilizer — Full Specification Sheet
Parameter	Specification
Rated Capacity	150 kVA (150,000 VA / 120 kW at 0.8 PF)
Input Voltage Window	300V – 480V AC Three-Phase (Custom 280V–480V available on request)
Output Voltage & Accuracy	415V AC ± 1% Line-to-Line
Phase Configuration	3-Phase, 4-Wire (Star / Neutral)
Cooling Type	Oil Cooled (ONAN – Mineral Oil per IS 335 / IEC 60296)
Correction Speed	45V / second
Response Time	< 30 milliseconds
Efficiency	98.5% at full load
Insulation Class & Enclosure	Class H (180°C), IP54 Enclosure
Protection Features	Over/Under Voltage Cutoff, Overload, Short Circuit, Phase Reversal, Single Phasing Preventer
Compliance Standards	IS 9815:2018, IS 14697:2022, IEC 61000

How a 150 kVA Servo Voltage Stabilizer Works

A continuous closed-loop correction system built on three coordinated stages: sensing, mechanical actuation, and series transformer correction.

Continuous Microcontroller Sensing

A dedicated microcontroller continuously samples all three input phases at high resolution, comparing instantaneous RMS voltage against the 415V ± 1% setpoint. Any deviation — sag, surge, or phase imbalance — is detected within milliseconds and converted into a correction command sent to the servo drive circuit.

Servo Motor Actuation

The correction signal drives a precision servo motor coupled to a carbon-brush roller assembly riding on the buck-boost autotransformer winding. The motor rotates the roller along the winding to physically adjust the tapping point, achieving smooth, stepless voltage correction rather than the discrete jumps seen in relay-based stabilizers.

Buck-Boost Series Correction

The repositioned tap changes the turns ratio of a series buck-boost transformer wired in-line with the load. This transformer either adds to (boost) or subtracts from (buck) the incoming line voltage, delivering a stabilized 415V output to connected machinery — all while the unit remains fully immersed and cooled in mineral oil, scaled for the higher continuous load of the 150 kVA frame.

Industrial Applications

The 150 kVA capacity band suits larger production floors and multi-machine setups sharing a single feeder.

Multi-Machine CNC Banks

Stabilizes shared feeders powering several CNC machining centers simultaneously, preventing cross-machine voltage interference.

Large Injection Molding Lines

Handles higher heater-band and hydraulic servo pump loads across multi-cavity or multi-machine molding setups.

Textile Mills

Supports larger banks of looms, spinning frames, and drive motors across extended production floors.

Medical Imaging Equipment

Delivers tight regulation for CT, MRI, and X-ray systems, including facilities running multiple imaging suites on one supply.

Heavy Industrial Automation

Protects PLC racks, VFDs, and robotic cell clusters from grid fluctuations common in industrial estates with shared transformer loading.

HVAC & Compressor Plants

Prevents motor overheating and premature winding failure on larger compressor banks and chiller plant motors.

Air Cooled vs. Oil Cooled — 150 kVA Comparison

At 150 kVA, thermal management is even more decisive for unit longevity and overload tolerance than at lower capacities.

Parameter	Air Cooled	Oil Cooled (Recommended at 150 kVA)
Thermal Buffer Capacity	Low – heat dissipates only via forced air over windings	High – oil mass absorbs and evenly distributes a larger heat load
Enclosure Protection	Typically IP23 / IP42	IP54 – sealed against dust and moisture ingress
Overload Tolerance	Limited short-term overload margin at this capacity	Higher short-term overload tolerance due to oil thermal inertia
Dielectric Insulation	Air-insulated windings	Oil-insulated windings — superior dielectric strength at higher current
Maintenance	Requires periodic fan and filter maintenance	Requires periodic oil quality testing; fewer moving parts
Suitability at 150 kVA	Not typically recommended at this capacity	Standard specification for 150 kVA+ continuous industrial duty

Engineering Note: At 150 kVA, sustained winding losses generate greater heat than at 100 kVA, making oil immersion (ONAN) the standard specification rather than an option. Oil cooling manages this heat load far more effectively than forced-air designs across continuous multi-shift industrial operation.

Compliance & Standards

Manufactured and tested against applicable Indian and international standards for voltage regulation equipment.

IS 9815:2018 Specification for AC automatic voltage regulators (servo type).

IS 14697:2022 General requirements for AC and DC servo-controlled voltage stabilizers.

IEC 61000 Electromagnetic compatibility (EMC) requirements for industrial power equipment.

IS 335 / IEC 60296 Mineral insulating oil specification for transformer and stabilizer oil-cooling systems.

Frequently Asked Questions

Technical answers to the most common questions on 150 kVA servo voltage stabilizers.

What is the maximum kW load a 150 kVA servo stabilizer can handle?

At a standard industrial power factor of 0.8 lagging, this unit supports a continuous active load of up to 120 kW — enough for larger CNC banks or combined production floor loads. Loads closer to unity power factor can draw nearer the full 150 kW apparent capacity.

Why choose Oil Cooled over Air Cooled for a 150 kVA unit?

At 150 kVA, winding losses generate substantial sustained heat that air cooling struggles to dissipate evenly. Oil immersion gives the windings a large thermal buffer, superior dielectric insulation, and a higher IP54 enclosure rating, along with better tolerance for short-term overloads.

How does ±1% voltage accuracy protect CNC and automated machinery at 150 kVA scale?

At 150 kVA, multiple machines and control systems often share the same feeder. A ±1% regulation band keeps supply voltage nearly constant across all connected loads simultaneously, preventing positioning drift and premature failure of shared control electronics.

What protection systems come standard with this unit?

Over/under voltage cutoff, overload protection, short circuit protection, phase reversal protection, and a single phasing preventer are all built into the standard control panel.

Request a Factory Quote on the 150 kVA Servo Voltage Stabilizer

Speak directly with our engineering team for site-specific load calculations, delivery timelines, and pricing.

Call 8882730630