Short answer: add up the real power draw of every item on stage in kilowatts, divide that total by a 0.8 power factor to get kVA, then size the generator so your load lands at 70 to 80 percent of its rated output. For a 300 guest gala with an LED wall and moving lights, that calculation comes out around 38 kW of load and a 60 to 75 kVA generator. The most common mistake is adding up the wattage printed on equipment labels. That method inflates the load two or three times over and pushes you into an oversized unit that burns fuel, runs badly and never sees enough load to stay healthy.
How the calculation works, in three steps
Step one: total the real draw of every piece of equipment in kilowatts. Step two: divide by 0.8 to convert to kVA, because generators are rated in kVA and the industry standard power factor is 0.8, which means a 100 kVA unit delivers 80 kW. Step three: scale up for the loading band the generator actually likes. Take a 300 guest gala: a 6x3 metre LED wall, 16 moving heads, 24 LED washes, eight active speakers and four subs, a console and a wireless mic rack, a video switcher and two laptops. Peak load for that rig works out at roughly 38 kW. Divide 38 by 0.75 and you get 51 kW, divide that by 0.8 and you land on 63 kVA, so a 66 or 75 kVA unit is the right call. One warning: do not apply your safety margin twice. Either add 25 percent to the load or work from the loading percentage. Stack both and you end up renting double the machine you need.
Label watts and wall watts are two different numbers
On the audio side the gap is startling. The amplifier module in a QSC K12.2 active speaker is rated at 2000 watts peak and the box is specified at 132 dB peak SPL at one metre. The same manufacturer sheet lists its draw at 1/8 power, which represents typical music program material, as 1.1 A at 230 V. Call it 250 VA. An eight box system looks like 16 kW on paper and pulls around 2 kW in the room. Lighting behaves the opposite way, because moving heads draw close to their rating and draw it continuously. The Martin ERA 600 Performance runs a 550 watt LED engine, yet the manufacturer quotes typical consumption of 778 watts, or 3.2 A at 230 V. Smaller bodies are far lighter on power: the Martin RUSH MH 5 Profile lists typical consumption of 165 watts. Build your table with real draw for audio and label figures for lighting.
Size the LED wall on peak, not average
Power draw on rental LED panels depends entirely on content. Manufacturer data for P3.91 rental panels puts average consumption at 300 to 400 watts per square metre, rising to 800 to 900 watts on full white at high brightness. A 6x3 metre wall is 18 square metres, so 6 kW on average and 14 kW at peak. That gap is enough to trip a generator chosen with no margin. Corporate slide decks tend to run on light backgrounds with plenty of white, and the opening film usually plays at full brightness. Plan the electrical side around the peak, then pull actual consumption down by running the wall at 40 to 50 percent brightness. Worth adding: most rental cabinets have a second power input, and feeding it from a separate circuit keeps the wall alive if one feed drops.
kW or kVA? Do not skip the phase maths
A generator plate carries two numbers: kVA for apparent power, kW for real power. Power factor is the link between them. In a three phase system, apparent power is the square root of three multiplied by line voltage and current, and you multiply that by the power factor to reach real power. The formula pays off when you read a venue spec: at 400 V, a 63 A CEE outlet gives you 43.6 kVA and a 125 A outlet gives you 86.6 kVA. If house power already covers the load you calculated, the generator conversation never has to start. Watch phase balance while you distribute: lighting on one phase, the LED wall on the second, audio and recording on the third. It lowers neutral current and cuts the risk of hum in the sound system.
Why the generator should run at 70 to 80 percent load
A diesel generator is happiest between 70 and 80 percent of its rated output. ISO 8528-1 caps the 24 hour average load factor at 70 percent of the nameplate rating for both prime (PRP) and emergency standby (ESP) classes, and the Cummins technical paper on ISO 8528-1 ratings walks through the detail. There is a floor as well. Run for hours below 30 percent load and the engine never reaches full operating temperature, so unburnt fuel and soot collect in the exhaust. The industry calls it wet stacking, and it raises fuel use and leaves you with a maintenance bill. In practice: hiring a 250 kVA unit for a 40 kW event load is not cautious, it is harmful. Where load swings hard across the day, rehearsal lighting only in the morning and full show at night, two smaller units or a split between house power and the generator beats one large machine.
Fuel, runtime and noise
Fuel is the easy part. Manufacturer consumption tables put a 100 kVA class diesel generator at roughly 14 to 15 litres per hour at 75 percent load. If build, rehearsal and show add up to 10 hours, that is close to 150 litres. Ask how many hours the tank holds and keep refuelling out of the middle of the programme, because taking on fuel while the stage is live is a risk you do not want. Noise deserves its own line in the plan. Canopy silent sets typically sit at 70 to 75 dB(A) at 7 metres, and super silent enclosures drop below 60 dB(A). A unit standing ten metres behind the stage will be audible in the quiet moments of a presentation. Outdoor events in Turkey also fall under the Environmental Noise Control Regulation (Official Gazette, 30 November 2022, no. 32029), which sets limit values for music venues in its Annex 2. Place the set away from guests and microphones, and choose the exhaust direction with the wind in mind.
Distribution and safety: 30 mA, TN-C and cable routes
Event power is a temporary installation and it has its own rulebook. IEC 60364-7-711 covers exhibitions, shows and stands as a separate section (2018 edition): TN-C systems are not permitted, the supply to each temporary structure needs 300 mA residual current protection, and socket outlet circuits need 30 mA protection. The code of practice the entertainment industry works to for temporary electrical systems is BS 7909, currently BS 7909:2023+A1:2024. Turkish regulation makes residual current protection mandatory too, applied at two thresholds: 30 mA for personal protection and 300 mA for fire protection. Factor in voltage drop as well. Annex G of IEC 60364-5-52 recommends 3 percent on lighting circuits and 5 percent on others, so if you are running 80 metres of cable from a generator in the car park to the stage, size the conductors on that calculation rather than by eye. Then the physical side: rubber sheathed flexible cable, cable ramps at guest crossings, locked and labelled distribution boards, and an RCD test before doors open. A small UPS on the show laptop, the console and the interpretation system hides the momentary gap when the supply switches over.
What to have ready before you ask for a quote
A short list is enough to specify the generator and the distribution: the power the venue already provides and its outlet type (32, 63 or 125 A CEE), what the stage build contains (square metres of LED, number of moving heads, size of the sound system), build and show hours, the distance from the stage to any spot where a generator can stand, and whether catering equipment will run off house power. With those answers we can produce the load table and give you a kVA figure in one pass. Tales Event delivers sound, lighting, staging and LED across Turkey with a single crew, so the power plan is not a separate line item. It comes out of the same conversation as the stage design.
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