Normal supply limits, and what to do outside them.
Learning Track · Module 6: Faults · Step 40 of 101
Showing content for Europe. Change the region at the top of the page.
Europe: IEC 60038 and EN 50160 give 230 V ±10%: 207 V to 253 V. OpenSLMS uses this band for alarms by default.
Middle East: Most GCC utilities use 230 V with about ±10% (207 V to 253 V). Check the limits in your utility's regulations.
South Asia: Indian supply rules allow about ±6% at low voltage (216 V to 244 V), but real supply often varies more. Many specifications ask drivers to work from 140 V to 300 V. Set alarm limits to match your drivers.
USA: ANSI C84.1 Range A allows ±5% at the service point. For 120 V that is 114 V to 126 V, and for 277 V it is about 263 V to 291 V. Set alarm limits for each supply voltage.
Low voltage
- Long cable with too small a cross-section.
- Too much load on one phase.
- A loose or corroded joint.
- Low supply from the network.
High voltage
A lost neutral is the most dangerous cause. Lights on a lightly loaded phase can get close to phase-to-phase voltage. This destroys drivers fast. Treat a sudden high voltage on one phase as Critical.
Surge protection devices in the cabinet and each luminaire protect against lightning and switching surges. Check their status at each preventive visit.
Sources
- IEC 60038 Standard voltages
- EN 50160
- ANSI C84.1
Changes: 30 October 2026: First publication: guides for Europe, the Middle East, South Asia, and the USA; failure library; tender clause library; comparisons; tools; downloads. See the changelog. Found a mistake? Report it.