In DIN VDE 0298-4 (based on HD 384.5.523, which in turn is based on the IEC 60364-5-523 standard) "Use of cables and insulated lines for power installations, Part 4: Recommended values for the current-carrying capacity of cables and lines for fixed installation in and on buildings and of ﬂexible lines", the permissible current-carrying capacities are given in extensive tables as a function of the type of installation, for very different types of installation, operating and ambient temperatures.
In principle, through-wiring through luminaires can be provided by the luminaire installer (i.e. on site). However, it must be ensured that the minimum voltage of 207 V (derived from the uniform mains voltage of 230 V±10% implemented in Europe until 2008) is available even at the most distant luminaire and that the voltage drop of 4.0% is not exceeded (see below). Accordingly, a sufficient conductor cross-section must be selected with regard to the current-carrying capacity and the voltage drop.
In the case of luminaires as a continuous row, the mains connection can be laid as through-wiring from one luminaire to the next. It must be ensured that the permissible operating temperature of the line insulation is not exceeded. According to VDE 0100 Part 559 "Installation of low-voltage systems - Luminaires and lighting systems", cables and conductors may be installed in the luminaire as through-wiring if they comply with the temperature specifications of the luminaire manufacturer, e.g. by the symbol . Otherwise, heat-resistant silicone cables are recommended.
Wires of several luminaire circuits may be routed together in luminaires, provided they are designed for this purpose. Through-wiring may also be routed through the luminaire without being connected to it.
The inner and outer heat-resistant PVC cables supplied with the luminaire, i.e. pre-assembled, in accordance with luminaire regulation EN 60589-1:2012 have a heat resistance of up to 105°C. Through-wiring supplied by TRILUX consists of color-coded, heat-resistant individual conductors 1.5 mm2 or 2.5 mm2.
Since the load on the through-wiring and the associated heating can also have repercussions on other components of the luminaires, TRILUX continuous lines are basically tested with a load on the through-wiring of 10 A(16 A) with a conductor cross-section of 1.5 mm2 (2.5 mm2).