High and low voltage in led systems: a complete guide

High voltage and low voltage: definitions and regulatory framework 

First, let's clarify what is meant by high voltage and low voltage, to then examine the current regulations governing these two distinct systems.

What is meant by high voltage and low voltage?

In the context of LED lighting and electrical installations more broadly, the definitions of high voltage and low voltage are governed by precise technical and legislative standards. Low voltage (LV) in Italy and Europe, per the CEI 11-1 standard, encompasses all systems with a nominal voltage not exceeding 1000V alternating current (AC) and 1500V direct current (DC) between conductors. However, regarding personal safety specifically, "low voltage" in the strict (and safer) sense refers to voltages below 50V AC and 120V DC—the touch voltage limit.

High voltage (HV) in LED lighting generally refers to systems that operate directly at mains voltage—i.e., 230V AC (single-phase) or 400V AC (three-phase) in Europe. For LED strips, the term "high voltage" is often used for products operating at 110V–240V AC, even though technically they still fall within the regulatory definition of low voltage. The true practical distinction in the LED industry lies between systems operating at mains voltage (220V–240V AC) and extra-low voltage systems (SELV – Safety Extra-Low Voltage), typically 12V DC or 24V DC.

Italian and european regulatory framework

The design and installation of LED systems must comply with a comprehensive regulatory framework. Key reference standards include:

High voltage: technical analysis of 220V–240V AC systems 

To better illustrate why selecting the appropriate system during the design phase is critical, we will examine contexts where high-voltage or low-voltage installations are preferred. 

What is meant by high voltage in LED applications?

In LED lighting, high voltage generally refers to the direct use of alternating current (AC) mains voltage without intermediate transformation. High-voltage LED strips are engineered with specialized LED chips and integrated circuits enabling direct operation at 110V, 220V, or 240V AC. These products integrate current-limiting resistors and rectifier circuits directly onto the strip, eliminating— in some cases—the need for an external power supply, though a dedicated LED driver is still required for regulation and protection.

Advantages of high-voltage LED systems

High-voltage systems offer several operational and economic benefits:

Reduced voltage drop: For equivalent transmitted power and cable cross-section, higher-voltage systems experience significantly less voltage drop (ΔV = R × I). This enables powering very long LED strips (up to 100 consecutive meters with quality products) without noticeable brightness loss at the ends. For a 100-meter installation at 24V DC using a 14.4W/m strip, voltage drop could exceed 20% with 1.5mm² cable, whereas at 230V AC it would remain below 2%.

Technical analysis of low-voltage systems (12V/24V DC)

While high-voltage LED strips enable very long installations, low-voltage strips offer another decisive advantage that should not be overlooked.

Electrical safety in low-voltage systems

The primary advantage of low-voltage systems—particularly in the SELV (Safety Extra-Low Voltage) configuration—is intrinsic human safety. At voltages below 50V AC and 120V DC, the risk of cardiac fibrillation from direct contact is extremely low. This makes 12V and 24V DC systems ideal for damp environments (bathrooms, kitchens, outdoors), public spaces, children’s areas, or any setting where accidental contact with live components is plausible.

Comparison: high voltage vs. specific use cases

Below is a summary of key motivations and scenarios guiding the choice between high-voltage and low-voltage LED strip installations.

When to choose high-voltage LED strips?

Long, linear installations: lighting cornices, soffits, building perimeters—where runs exceed 20–30 meters without intermediate power feeds.

Industrial and commercial applications: warehouses, factories, showrooms—where simplified wiring and reduced installation costs are priorities.

When to prefer low-voltage systems?

Residential and design-focused applications: furniture, niches, staircases—where user proximity and safety are paramount.

Damp or accessible outdoor environments: swimming pools, gardens, bathrooms, kitchens, saunas—where regulations and prudence mandate safety-class voltages.

Statistical data and market trends

Let’s examine key market figures to understand evolving industry preferences. According to a 2023 TrendForce report, the professional LED systems market distribution by voltage type is: 58% low voltage (12V/24V DC), 35% high voltage (110V–240V AC), 7% hybrid systems. However, within the large commercial/industrial installation segment, high-voltage solutions account for 52% of the market share, driven by the wiring efficiency advantages outlined earlier.

High voltage and low voltage: where design meets safety standards

Selecting between high-voltage and low-voltage LED systems is not a binary decision—it requires a careful technical, regulatory, and application-based evaluation. While low-voltage systems deliver safety and flexibility for precision and residential uses, high-voltage systems provide efficiency and cost-effectiveness for large-scale projects. Future trends point toward intelligent systems integrating both technologies, with controllers capable of managing multiple voltages according to the specific needs of each installation segment.