What standards do Prima Transformers 3 phase power units adhere to?

Our units are engineered in accordance with Indian and International electrical standards including IS 2026, IS 11171, IS 12012, and relevant IEC 60076 specifications, verified through rigorous routine tests and CE conformity protocols.

Can you configure custom voltage taps and vector configurations?

Yes. While Dyn11 is standard, our engineering team regularly designs custom vector groupings (Star-Star, Delta-Delta, Star-Delta with neutral), specialized multi-voltage taps, and enclosures up to IP23/IP54 for overseas projects.

3 Phase Power Transformers & Isolation Transformers

Q: What is the difference between a standard 3 phase transformer and a 3 phase isolation transformer?

A standard three phase transformer modifies voltage levels, while a three phase isolation transformer features galvanically segregated primary and secondary windings. This physical isolation prevents DC noise, ground loops, common-mode electrical transients, and equipment damage in high-precision industrial circuits.

Industrial Magnetics Engineering

High-Performance 3 Phase Electrical Power Isolation Transformers

Prima Transformers Pvt. Ltd. manufactures and exports high-efficiency Three Phase Power and Isolation Transformers engineered specifically to deliver galvanic circuit segregation, clean power conditioning, and precise voltage step-up or step-down functionality for international industrial plants, drives, and OEM automation architectures.

Built upon an optimized three-legged electrical-grade grain-oriented (CRGO) silicon steel core, each limb carries dedicated, insulated primary and secondary winding assemblies. This architecture guarantees true galvanic isolation, ensuring complete physical separation between the input power grid and the secondary distribution load, attenuating common-mode electrical transients, ground loops, and harmonic distortion.

From 250 VA up to 1000 kVA (with capability scaling up to 5000 kVA for specialized turnkey projects), our power transformers adhere to stringent Indian and International manufacturing standards including IS 2026, IS 11171, and IS 12012, carrying CE marking for European and global compliance.

Heavy duty three phase power isolation transformer manufactured by Prima Transformers

Complete Galvanic Isolation

Physical separation of primary and secondary copper windings ensures the secondary output circuit remains floating with respect to ground unless deliberately referenced, protecting critical electronics and industrial PLC automation from severe ground fault transients.

VPI Resin Impregnation

Windings undergo precision vacuum pressure impregnation (VPI) with high-grade polyester resin. This eliminates microscopic air voids, enhances dielectric breakdown resistance, mitigates moisture ingress, and minimizes audible magnetostrictive hum during full-load cycles.

Full Type & Routine Tested

Every manufactured transformer is evaluated in-house utilizing computerized open/short circuit testers, double-voltage double-frequency (DVDF) induced overvoltage validation, high-voltage breakdown benches, and digital micro-ohmmeter winding resistance analytics.

Engineering Configurations

Technical Specifications & Constructional Attributes

Engineered to withstand heavy duty cycling, variable thermal loads, and clean integration into motor control centers (MCC), drive panels, and commercial power substations.

Performance Specifications

Rated Output Capacity 250 VA – 1000 kVA

Max. Input Voltage Up to 750 V

Max. Output Voltage Up to 750 V

Operating Frequency 50 Hz / 60 Hz

Vector Group Dyn11 (Standard) / Custom

Thermal Insulation Class Class B / Class F / Class H

Standard Ingress Protection IP 00 (Enclosures up to IP 23 / 54)

Ambient Temperature Max. 40° C (Standard Design)

Max. Rated Direct Current 65 A to 1500 A Terminations

Applicable Test Standards IS 2026, IS 11171, IS 12012, IEC

Mechanical Construction Details

Modular Core Clamping: Heavy-gauge U-section channels with high tensile tie-rods ensure uniform clamping pressure across all core laminations, preventing structural distortion during short-circuit faults.
Versatile Termination Options: Safe-to-touch finger-proof screw terminals up to 135 A; threaded copper studs up to 450 A; high-conductivity electrolytic flat busbars with shrouding up to 1500 A.
Dielectric & Moisture Protection: High-grade vacuum-pressure impregnation utilizing polyester class resin shields against harsh industrial atmospheres, humidity, and chemical contaminants.
Custom Enclosures & Integration: Open core assembly (IP00) for control cabinet incorporation, or sheet steel vented cubicles engineered for floor mounting up to IP23/IP54 ingress levels.
Low Noise & Eddy Loss Design: Precision cut, mitered cold-rolled grain-oriented electrical silicon steel leaves minimal air gaps, drastically minimizing excitation current and no-load watt losses.

Standard Engineering Dimensions

3 Phase Power Transformer Dimension Schedule

Reference sizing matrix for open dry-type construction across standard kVA outputs. Custom physical layouts, tapped configurations, and seismic-rated mounting dimensions available on request.

IS 2026 Standard IS 11171 Standard IS 12012 Standard CE Compliance Verification

Rating (kVA)	Height (mm)	Width (mm)	Depth (mm)	Mounting X (mm)	Mounting Y (mm)	Slot Size (mm)	Approx. Weight (kg)	Core Figure
0.5 kVA	200	180	125	160	90	8 x 20	11	Figure A
0.75 kVA	240	240	121	160	75	8 x 20	13	Figure A
1.0 kVA	240	240	120	160	75	8 x 20	14	Figure A
1.25 kVA	240	240	135	160	90	8 x 20	19	Figure A
1.5 kVA	240	240	145	160	100	8 x 20	21	Figure A
2.0 kVA	300	300	150	180	90	10 x 25	26	Figure A
2.5 kVA	300	300	160	180	100	10 x 25	30	Figure A
3.0 kVA	300	300	170	180	110	10 x 25	34	Figure A
4.0 kVA	300	300	180	180	120	10 x 25	41	Figure A
5.0 kVA	360	360	200	200	135	13 x 28	53	Figure A
6.0 kVA	360	360	210	200	145	13 x 28	61	Figure A
7.5 kVA	360	360	210	200	145	13 x 28	65	Figure A
10 kVA	360	360	215	200	150	13 x 28	72	Figure A
12.5 kVA	360	360	215	200	150	13 x 28	83	Figure A
16 kVA	420	420	250	220	170	13 x 28	110	Figure A
20 kVA	420	420	260	220	180	13 x 28	127	Figure A
25 kVA	460	480	285	220	200	13 x 28	161	Figure A
30 kVA	520	520	315	220	200	13 x 28	201	Figure A
35 kVA	520	520	315	220	205	13 x 28	222	Figure A
40 kVA	520	520	320	220	210	13 x 28	232	Figure A
45 kVA	580	560	335	220	205	13 x 28	261	Figure A
50 kVA	505	840	500	250	265	15 x 35	260	Figure B
60 kVA	505	860	500	250	270	15 x 35	285	Figure B
75 kVA	550	875	500	250	265	15 x 35	329	Figure B
100 kVA	560	900	520	250	270	15 x 35	384	Figure B
125 kVA	595	960	550	250	280	15 x 35	483	Figure B
150 kVA	635	1010	570	250	290	15 x 35	548	Figure B

Deployment Domains

Core Industrial Sector Applications

Trusted across harsh manufacturing environments where continuity and dielectric stability are critical.

VFDs & Industrial Drives

Supplying clean, isolated three-phase power to variable frequency drives (VFD) and rectifiers, preventing high-frequency noise reflections back into the central distribution transformer.

Precision Machine Tools & CNC

Galvanically shielding computer numerical control (CNC) equipment, PLCs, and delicate automation controllers from severe line voltage surges, voltage drops, and earth potential shifts.

MCC, PCC & Sub-Distribution

Providing independent derived neutral lines and safe voltage matching for imported European, American, or Asian production machinery in steel, cement, and chemical facilities.

Procurement Guidance

Technical FAQ for Engineering & Sourcing Teams

What is the difference between a standard 3 phase transformer and a 3 phase isolation transformer?

A standard 3 phase transformer may use a common winding design (like an autotransformer) to step voltage up or down, offering no physical separation between input and output. In contrast, a 3 phase isolation transformer features magnetically coupled but mechanically and electrically isolated primary and secondary windings. This creates a floating secondary reference that eliminates ground loops, blocks DC bias, mitigates common-mode spikes, and ensures operator and equipment protection.

What quality and dielectric tests are performed on power transformers before export dispatch?

Every transformer undergoes complete routine testing in our Ahmedabad testing department prior to shipment. This includes computerized Open-Circuit (no-load core losses) and Short-Circuit (copper losses, impedance) analysis, High-Voltage dielectric breakdown testing, Double Voltage Double Frequency (DVDF) inter-turn stress tests, Insulation Resistance (Megger) checks, and digital micro-ohmmeter winding resistance measurement.

Can Prima Transformers produce units with custom input/output voltages and non-standard taps?

Yes. While 415V/400V/380V/480V are common, we routinely custom-engineer units up to 750V with off-circuit tap changers (e.g., ±2.5%, ±5%), customized vector groupings (Dyn11, Dyn5, Yyn0, Dd0), and multi-tap secondaries to meet worldwide site parameters.

What details should be included in an RFQ for rapid technical validation and quotation?

Please specify: Rated capacity (kVA), primary voltage and tapping requirements, secondary output voltage, operating frequency (50/60Hz), vector connection, desired insulation class (Class B/F/H), duty cycle, IP enclosure requirement (open IP00 or enclosed IP21/IP23), and any country-specific testing or documentation requirements.

Three Phase Power & Isolation Transformers