What does an LED driver do?

From 230 V AC to regulated direct current.

An LED cannot be connected directly to the mains supply. It requires a precisely regulated, low DC current to produce a stable light output without overheating or degrading prematurely. The driver converts the incoming 230 V AC supply to this regulated output — and does so consistently year after year, regardless of temperature swings, mains voltage variations, or transients from nearby lightning strikes.

VALDUR uses constant-current drivers rather than constant-voltage. This means the current through the LED module is held fixed regardless of how the forward voltage across the diodes changes over time or temperature — which is critical for consistent luminous output and predictable ageing behaviour.

The driver sits in its own sealed compartment within the luminaire housing, thermally isolated from the LED module's heat path, and is field-replaceable as a service part without dismounting the entire luminaire from the column.

Signal Path

230 V AC

Mains supply, 50 Hz

LED Driver

Constant current · PF ≥ 0.95 · surge protection

LED Module

Regulated DC current

Power Factor & Harmonics

Clean power is a procurement question.

Power factor (PF) ≥ 0.95

Power factor describes how efficiently the driver uses the supplied power. A low PF loads the grid unnecessarily and can in larger installations lead to penalty charges from the network operator. VALDUR drivers maintain PF ≥ 0.95 across the full dimming range, which is a common requirement in municipal procurement specifications.

Total harmonic distortion (THD) < 10 %

High harmonic distortion disturbs other connected loads and can produce increased losses in transformers and cables. VALDUR meets the requirements of EN 61000-3-2 with THD below 10 %, keeping the grid clean even in large-scale street lighting roll-outs.

Surge Protection

Built for unstable grids.

Luminaires on columns in open terrain, along coastal roads, and in harbour areas are exposed to voltage transients from lightning strikes and grid switching events far more frequently than indoor installations. VALDUR's driver incorporates built-in surge protection that absorbs these transients before they can damage the sensitive current-regulation components.

For environments with elevated risk — isolated columns, installations near high-voltage lines — a separate external surge protection device (SPD) can be specified at order stage as additional robustness beyond the driver's built-in protection. The SPD module carries a status indicator that shows when the protection has been expended and requires replacement.

Temperature & Service Life

Every degree counts.

Electrolytic capacitors are often the component in a driver that ages fastest, and the ageing rate approximately doubles for every 10 °C increase in operating temperature. Driver placement, thermal surface area, and thermal isolation from the LED module's heat path are therefore just as important for service life as the component selection itself.

VALDUR's SMC housing (see Materials) contributes here through low thermal conductivity from the environment into the electronics, keeping the driver's operating temperature stable even under direct solar loading.

Driver Families

Four levels of programmability.

VALDUR is supplied with Xitanium drivers from Signify (formerly Philips) in four variants. The right choice depends on how much control, diagnostics, and connectivity the project requires.

Standard

Xitanium LP

Lite Programmable

The baseline configuration. Dynadimmer function with 1–5 pre-set dimming profiles for night-time operation.

Extended

Xitanium FP

Full Programmable

Dynadimmer with more steps and finer adjustment, DALI support, and extended diagnostics. Supports sensor override to 100 % on occupancy detection.

Sensor-Ready

Xitanium SR

Sensor Ready

Pre-wired for sensors and wireless control systems without further modification to the luminaire.

Connected

Xitanium CR

Connected Ready

Wireless control, energy metering, and remote monitoring via the open D4i standard.

Temperature Monitoring

An NTC resistor monitors the heat.

The Xitanium FP and Xitanium LP SN drivers include built-in support for LED Module Temperature Protection (MTP) — a protective function that continuously reads the temperature of the LED module via an external NTC (Negative Temperature Coefficient) resistor and dims down operation if temperature becomes excessive.

Three standardised NTC types are supported directly without additional configuration. Other NTC types within the 5,000–25,000 Ω range can also be used after configuration.

NTC type	Component
10 kΩ	Murata NCP18XH103J03R
15 kΩ	Vishay NTCS0805E3153GMT
15 kΩ	Murata NCP15XW153E03RC + 390 Ω resistor in series with NTC

Key Data

Driver in VALDUR — summary

Parameter	Value
Input voltage	220 – 240 V AC, 50 Hz
Regulation	Constant current
Power factor (PF)	≥ 0.95
Total harmonic distortion (THD)	< 10 %
Control interface	0-10 V / DALI-2 / Zhaga Book 18 / Fixed
Placement	Thermally isolated from LED module, IP66-sealed compartment
Replaceability	Service part, field-replaceable
Temperature protection	NTC-based LED module protection (MTP)
Warranty	5 years

Standards

Relevant standards for LED drivers

IEC 61347-2-13

Safety requirements for electronic control gear for LED modules.

EN 61000-3-2

Limits for harmonic current emissions in electrical supply systems.

EN 62384

Performance requirements for DC and AC-supplied electronic control gear for LED.

IEC 61547

EMC immunity requirements for general lighting equipment.

Frequently Asked Questions

About LED drivers

What is the difference between constant-current and constant-voltage?

With constant current, the current through the LED module is held fixed whilst voltage is allowed to vary — providing consistent luminous output even as the diodes' characteristics change with temperature and age. Constant voltage is more common in low-voltage applications such as LED strips but is less suited to high-power street lighting.

Can the driver be replaced separately if it fails?

Yes. The driver is mounted as a separate service part and can be replaced in the field without dismounting the luminaire from the column or affecting the LED module.

How does the driver affect the luminaire's overall service life?

In practice, the driver is frequently the component that limits service life first, because its electrolytic capacitors age faster than modern LED chips — read more in Why the driver's capacitors determine service life. Correct thermal design and surge protection are therefore at least as important as the LED module's L90/B10 specification.

Are VALDUR's drivers compatible with existing DALI systems?

Yes. DALI-2 is an open industry-standard protocol, and VALDUR can be integrated into existing DALI systems from other suppliers provided they follow the same standard. See Controls for more detail.

What warranty applies to the driver?

The driver and other electronics carry a 5-year functional warranty (ALEM-09). The luminaire housing, which bears the structural load, has a separate 20-year warranty.

Read Further