When it comes to temperature control devices — such as thermostats, chronothermostats, regulators, and central units — one key aspect that is often overlooked is the electrical insulation class.
This parameter defines the level of protection a device provides against electric shock and current leakage, ensuring both system safety and user protection.
But what exactly does “insulation class” mean? And why is it important to understand it when choosing products for temperature regulation?
What “insulation class” means
The insulation class is a classification established by international standards (IEC/EN 61140 and IEC 60335) that defines the type of electrical protection built into a device.
It specifies how the product prevents accidental contact with live parts and how it handles grounding.
The main insulation classes are:
- Class I:
Class I devices have basic insulation and require a protective earth connection.
In case of a fault, any leakage current is safely discharged to ground, preventing electric shock.
These devices are typically used in systems with exposed metal parts or where additional safety is required. - Class II:
Devices in this class have double or reinforced insulation, eliminating the need for grounding.
They are marked with a symbol of two concentric squares and provide high safety even in domestic or commercial settings.
Most wall-mounted thermostats and chronothermostats fall into this category, as they operate at low voltage and have fully insulated internal components. - Class III:
Class III devices are powered by Safety Extra-Low Voltage (SELV, typically below 50 V).
The risk of electric shock is virtually eliminated, although the protection also depends on the safety of the power source.
These include radio thermostats or low-voltage-powered units, where electrical connections are minimal or indirect.
Why insulation class matters in temperature control
In temperature control systems, the insulation class affects several key aspects of the product:
- User safety: ensures that the device remains safe to touch even in case of electrical faults or humid conditions.
- Long-term reliability: proper insulation protects internal components from overvoltage, dust, and moisture, extending the product’s lifespan.
- Regulatory compliance: correct classification is essential for CE marking and compliance with European safety directives.
- Installation flexibility: Class II and Class III devices are ideal for domestic or office installations, especially where grounding is not available.
How to choose the right device
Choosing the appropriate insulation class depends mainly on:
- the type of electrical system (with or without grounding);
- the installation environment (residential, industrial, humid, outdoor, etc.);
- the required safety level, as specified by regulations or project specifications.
In general:
- for standard residential installations, Class II devices are the most common and reliable choice;
- for remote control systems or wireless modules, Class III products offer maximum safety and versatility;
- in industrial settings or systems with grounded metal components, Class I devices may still be required.
IMIT’s commitment to safety
All IMIT temperature control devices — from Orion digital chronothermostats to fan-coil regulators — are designed and tested to ensure the highest standards of electrical safety and compliance with international regulations.
At IMIT, insulation quality is not just a technical requirement — it is a guarantee of reliability and protection for both installers and end users.
This reflects IMIT’s core philosophy: comfort, efficiency, and safety in every environment.