Isolation Stations — Power Transformations

Isolation stations provide power transformations that prevent the flow of unwanted currents, such as ground loops and electrical noise, between connected devices. They ensure safety, protect equipment and improve the quality of the power supply. People often pair these stations with medical equipment, personal health devices and industrial machinery.

For those who work in sectors that must prioritize safety, efficiency and reliability, an isolation transformer can reduce the risk of electrical shocks, shield sensitive equipment from damage and enhance your electrical systems' overall reliability. This guide explains how isolation stations work and their various purposes across industries.

What Are Power Isolation Stations? 

Power isolation stations are protective barriers for electrical systems. They use isolation transformers to separate parts of a circuit, ensuring electricity flows safely without interference or disruptions. Isolation stations maintain a stable and clean power supply, especially in medical and industrial environments where receiving safe and reliable power is paramount.

Conventional power transformers step voltage levels up or down between different parts of the power distribution system without any isolation. In contrast, isolation transformers transfer electricity from an alternating current power source to a device while separating the device from the power source.

Here's how power isolation stations typically work.

• Electrical isolation: The transformer's primary and secondary windings are electrically disconnected. This galvanic isolation prevents direct current flow between the input and output sides, keeping equipment and people safe.
• Voltage transformation: Like regular transformers, isolation transformers step the voltage level up or down from the input side to the output side based on the turn ratio of the windings. They convert voltage while maintaining electrical isolation.
• Noise and interference suppression: Isolating the circuits suppresses common mode noise, electromagnetic interference and ground loops that can affect sensitive equipment by preventing these disturbances from passing through to the output devices.
• Enhanced safety: In case of a fault or short circuit on one side of the transformer, the galvanic isolation prevents the faulty current from flowing to the other side, reducing the risk of damaging equipment and harming employees.

Types of Isolation Transformers 

We categorize isolation transformers based on their construction, application and features. These are a few examples of different types of isolation transformers.

• Single-phase: Single-phase electrical systems with isolation transform voltage for residential and small commercial applications.
• Three-phase: These power systems have three power lines at a 120-degree angle. Three-phase transformers convert voltage for industrial equipment while supplying isolation.
• Medical-grade: These transformers meet 60601-1 safety standards for medical power supplies and equipment.
• Shielded: Shielded isolation transformers give extra protection against electromagnetic and radiofrequency interference.
• Toroidal: Toroidal isolation transformers use doughnut-shaped cores for improved efficiency and reduced EMI in a more compact size compared to traditional core types.
• Industrial grade: Isolation transformers built to withstand industrial environments provide robust isolation and protection for industrial power supplies, such as machinery, equipment and control systems.

Design and Features 

Isolation transformers must adhere to specific design specifications, especially in medical applications or industrial services. Here are some design features that create effective and safe isolation stations.

• Core material: The core usually consists of laminated steel, silicon, iron, nickel-iron alloy, amorphous alloys or iron powder.
• Windings: The primary and secondary windings transform voltage while maintaining electrical isolation.
• Insulation: Critical for preventing electrical contact between windings, insulation may consist of enamel coating, paper or synthetic materials.
• Bobbin or former: Made of plastic or resin, these support winding geometry.
• Encapsulation: This technology provides insulation and mechanical protection, reduces vibration and lowers the chance of moisture ingress.
• Terminals: Some isolation transformers may have terminals or leads at the ends of the windings to connect the input and output circuits.
• Shielding: Shielding is an optional addition that gives an extra layer of protection against EMI and RFI in sensitive applications.
• Mounting and enclosure: Isolation transformers may sit in metal or plastic enclosures with ventilation slots.

Medical Power Isolation Stations 

Due to the critical services medical devices and equipment deliver, power isolation stations for medical applications need specialized design features to work sufficiently at high standards.

• Reinforced insulation helps meet low leakage requirements.
• Reliable isolation between the AC input, power supply, DC output and other electrical components allows medical personnel to work at isolation stations with less risk.
• Toroidal cores reduce stray magnetic fields and increase efficiency.
• Compared to traditional isolation stations, those used in the medical field are compact, lightweight and operate silently for less noise pollution.

Safety and Compliance 

Isolation transformers undergo rigorous testing to ensure compliance with safety standards, especially in the medical field. Industry certifications give you peace of mind that this equipment has all the essential safety features and quality requirements.

Here's an overview of a few regulatory standards that apply to isolation transformers.

• Underwriters Laboratories: UL certification ensures isolation transformers meet specific safety and performance standards set by this globally recognized safety organization.
• International Electrotechnical Commission: Standards under the IEC cover safety requirements for power transformers and power supply units, including the stringent safety standards required for medical electrical equipment.
• Conformité Européenne marking: The CE mark indicates that the isolation transformer complies with European Union health, safety and environmental regulations.
• International Organization for Standardization: Some standards under ISO specify requirements for designing and manufacturing medical devices.
• Restriction of Hazardous Substances: RoHS compliance ensures an isolation transformer contains no restricted substances that could impact the environment.

Factors to Consider When Choosing an Isolation Station

Focus on the following when considering other features in customizing isolation transformers to meet specific needs.

• Voltage ratings: Base your selection on the primary power supply voltage and required output voltage.
• Number of phases: Choose single-phase or three-phase options based on your load requirements.
• Load requirements: Consider the size and type of load for optimal performance.
• Location: Ensure the isolation station can withstand the effects of the environment where you will install it.

Implement an Isolation Station Solution With Astrodyne TDI

Isolation stations are critical in power transformations by providing galvanic segregation between different parts of a system. When you combine your essential components with isolation stations, your power supplies can deliver clean, stable power while mitigating electrical noise and disturbances.

Astrodyne TDI creates power isolation station solutions for clients with diverse needs. We provide high-quality products that comply with regulations and meet industry standards for performance and reliability. 

Are you ready to create robust power transformation setups? Do you need help with custom solutions? Get in touch with us and let's work together to create a system that will work for you.