Choosing the right isolation transformer is a critical decision to ensure operator safety and protect sensitive electrical equipment. In a market that exceeded 63.8 billion dollars in 2024, with expected annual growth of 6.6% until 2034, the demand for galvanic isolation solutions is becoming increasingly specific and technically advanced.
This technical guide offers electrical managers, facility managers and designers a structured approach to identifying the most suitable isolation transformer for specific plant requirements, with particular focus on sizing criteria and regulatory compliance.
Why is galvanic isolation crucial for electrical safety?
The concept of galvanic isolation explained
Galvanic isolation represents the complete physical separation between the primary and secondary windings of a transformer, eliminating any direct electrical connection between input and output. This key feature distinguishes isolation transformers from autotransformers, where a direct electrical link exists.
Galvanic separation is achieved through completely independent windings, mounted on a common magnetic core but electrically isolated from each other using high-dielectric-strength materials. This design ensures that energy is transferred exclusively by magnetic induction, completely interrupting ground circuits and leakage currents.
Difference between transformer and autotransformer
Understanding this technical distinction is essential to know when to opt for galvanic isolation:
- Isolation transformer: two separate windings, no electrical connection, full protection against leakage currents
- Autotransformer: single winding with intermediate tap, direct electrical connection, higher efficiency but no galvanic isolation
The most common disturbances on the electrical line
Problems that galvanic isolation can solve include:
- Ground loops: unwanted current circuits closing through the protective conductor
- Leakage currents: current flows to ground that can compromise sensitive equipment
- Common-mode disturbances: electromagnetic interference propagating through the supply network
- Common-mode voltages: Potential differences between neutral and earth causing malfunctions
According to industry technical sources, around 60-70% of damage to critical electronic equipment in hospitals and data centres is directly attributable to these electrical phenomena.
Risks and critical applications: when is an isolation transformer needed?
Medical sector: compliance and patient safety
In healthcare, isolation transformers are mandatory for powering medical equipment in specific group II rooms, according to EN 61558-2-15. This regulation sets specific requirements for:
- Transformers designed to supply medical premises with IT systems
- Voltages up to 1 kV and powers between 0.5 and 10 kVA
- Mandatory isolation shield connected to the local equipotential system
- Thermal protections and leakage current monitoring devices
The absence of galvanic isolation in medical environments can lead to:
- Microshock risks for patients
- Untimely tripping of differential protections
- Malfunction of life-saving equipment
Industrial plants: protection of PLCs and inverters
In industrial automation, PLCs, inverters and control systems are highly sensitive to electrical disturbances. Isolation transformers ensure:
- Elimination of ground loops that cause control system errors
- Protection against overvoltages that can damage power electronics
- Reduction of electromagnetic interference in industrial communication systems
Production downtime costs caused by electrical disturbances can range from €8,000 to €80,000 per hour in large manufacturing plants.
Data centres and telecoms: ensuring operational continuity
Data centres require “clean” power supply to ensure:
- Continuous operation of servers and cooling systems
- Protection of UPS systems against circulating currents
- Compliance with power quality standards
EV charging stations: user and vehicle safety
The growth of e-mobility requires isolation transformers for:
- User safety during charging
- Protection of on-board EV systems
- Compliance with electrical safety regulations
The Ortea Next solution: customised and compliant isolation transformers
Ortea Next offers a complete range of isolation transformers designed to meet the most specific needs of the industrial and commercial market. Our solutions include:
- Single-phase transformers: From 0.5 to 50 kVA for dedicated supplies
- Three-phase transformers: From 5 to 2000 kVA for large industrial plants
- Special versions: With electrostatic shielding and integrated filters
High-quality materials and certified production processes
Ortea Next’s “Made in Italy” production guarantees high quality standards and complete certifications. Our transformers fully comply with EN 61558-1 safety standards and are tested under rigorous protocols including:
- High-voltage insulation tests
- Heating and thermal stability tests
- Electromagnetic compatibility checks
- Quality control on each individual product
Custom design for specific needs
Extreme customisation capability sets Ortea Next apart in the market, enabling tailored solutions for every installation. Our technicians can adapt:
- Non-standard primary and secondary voltages
- IP protection grades up to IP54 for harsh industrial environments
- Special configurations with multiple taps or on-load switches
- Integrated accessories such as thermal protection and monitoring devices
Have a specific need? Speak to one of our engineers.
Selection criteria for correct transformer sizing
Power calculation (kVA)
Correct sizing begins with calculating the required apparent power:
- For single-phase loads: kVA = (V × I) / 1000
- For three-phase loads: kVA = (√3 × V × I) / 1000
It is essential to apply an oversizing margin of 15-25% to account for:
- Future load growth
- Inrush currents (which can be 5-15 times the rated current)
- Harmonic content of non-linear loads
- Power factor variations
Definition of input/output voltages
Voltage choice must consider:
- Available network voltage (400V, 230V, special voltages)
- Voltage required by loads
- Adaptation needs for imported equipment
- Neutral configuration (TN, TT, IT) of the electrical system
Evaluation of installation environment (IP, temperature)
Environmental conditions strongly influence the choice:
Ambient temperature:
- Standard reference: 40°C
- Derating required for higher temperatures
- 5% derating per 1000m altitude
IP protection degree:
- IP00: Installation in closed electrical panels
- IP23: Standard industrial environments
- IP44/IP54: Dusty or humid environments
Thermal insulation classes:
- Class A (105°C), B (130°C), F (155°C), H (180°C)
Additional factors: vector group and inrush current
Vector group: Selection depends on plant configuration (here are some examples):
- Dyn11: Delta-star with neutral, 330° phase shift
- Yyn0: Star-star, 0° phase shift
- YNd11: Star with neutral-delta, 330° phase shift
Inrush current management:
- Coordination with upstream protections
- Conductor sizing
- Assessment of network impact
For optimal sizing, contact our experts for a personalised consultation.
Why choose Ortea Next for your isolation transformers
Ortea Next represents over 50 years of Italian excellence in the design and manufacture of power quality solutions. Our leadership is based on:
Proven experience and global presence
With operations in over 100 countries and an international network of qualified distributors, Ortea Next guarantees local technical support even for the most complex projects.
Continuous innovation and advanced R&D
Our research and development centre invests constantly in new technologies to anticipate market needs and offer increasingly efficient and reliable solutions.
Certifications and regulatory compliance
All our transformers are designed and tested according to the strictest international standards:
- EN 61558-1: Transformer safety
- EN 61558-2-15: Transformers for medical rooms
- IEC 60076: Standards for power transformers
Discover our complete range of LV transformers and reactors, or explore the specifications of our power transformers.
Frequently asked questions (FAQ) about isolation transformers
What is the average lifespan of an Ortea Next isolation transformer?
Ortea Next transformers are designed for an operational life of at least 30 years under nominal use conditions. The quality of “Made in Italy” materials and strict quality controls ensure long-term reliability even in harsh environments.
Is it possible to get a transformer with non-standard voltages?
Yes, customisation is one of Ortea Next’s strengths. We can manufacture transformers with any combination of primary and secondary voltages, including for special applications with non-standard voltages or multiple outputs.
What kind of maintenance is required?
Ortea Next transformers require minimal maintenance. We recommend:
- Semi-annual visual inspection of connections
- Annual cleaning of cooling surfaces
- Five-yearly insulation checks with electrical testing
How to choose between an isolation transformer and an autotransformer?
The choice depends on the application:
- Isolation transformer: When galvanic separation is needed (medical environments, data centres, protection of sensitive equipment)
- Autotransformer: For simple voltage adaptation where galvanic isolation or leakage current protection is not required
What are the delivery times for a customised transformer?
Delivery times depend on technical specifications and required power:
- Standard transformers: 2-4 weeks
- Customised transformers: 4-8 weeks
- Special projects: On quotation, usually 6-12 weeks
Request a free consultation to choose the right isolation transformer for your application. Contact our experts for professional sizing.
