1️⃣ IEC
#️⃣ Low voltage installations supplied directly from a public low voltage distribution system: Lighting circuits 3 % Other uses (heating and power) 5 %
#️⃣ Low voltage installations supplied From private LV supply Lighting circuits 6 % Other uses (heating and power) 8 %
2️⃣ khahrama Electrical Regulations
The fall in voltage from the commencement of the customer’s mains to point on the installation shall not exceed 3% for lighting and 5% for other loads. Often it can be useful to apply values 2% to 3% for sub-mains 4% or 3% for final circuits.
3️⃣ Dewa Regulations
The maximum voltage drop from the point of supply to any point/equipment, appliances and apparatus connected in the wiring installation shall not exceed 4%
4️⃣ DISTRIBUTION PLANNING STANDARD “DPS” Voltage drop at customer supply interface points shall not exceed 5% of nominal voltage, i.e. from substation to customer location.
5️⃣ SBC 401 (Saudi Building Code)
Lighting Circuits 3% Other Circuits (Power, HVAC, etc.) 5%
6️⃣ NEC (NFPA 70)
The NEC suggests (based on the Informational Notes, not mandatory requirements): Branch circuits (from panel to load)≤ 3% Feeders (between panels)≤ 3% Total voltage drop (Feeder + Branch together)≤ 5%