In short. Event power is temporary but it is not improvised. The load changes between build, rehearsal, show and strike, the equipment is electronic and sensitive to voltage and frequency, the public walks past the cables, and a failure happens in front of everyone. The engineering answer is a programme-based load schedule, silent generators with redundancy for the loads that cannot fail, clean distribution with residual current protection and earthing, and a named person responsible for the installation throughout.
Loads that change with the programme
An exhibition, wedding, concert or corporate event has four distinct electrical phases, and the load in each is different. During the build, the demand is tools, work lighting and the first air-conditioning units in the marquee. During rehearsal and sound check, the stage, lighting rig and LED screens come alive for the first time, often all at once. During the show, the load is at its peak but is largely known. During strike, it falls back to work lighting and tools, often at night. A load schedule built around this programme separates peak simultaneous demand from equipment that never runs together, and avoids sizing the whole event for a figure that only occurs for two hours; the generator sizing guide explains diversity. The event power rental page covers the equipment side.
| Load group | Character | What it needs from the generator | Tolerable interruption |
|---|---|---|---|
| Stage audio and lighting consoles, LED walls, broadcast | Electronic, nonlinear, low inertia | Stable voltage and frequency, low harmonic distortion, no break | None during the show |
| Moving lights, dimmers, amplifiers | Nonlinear, high crest factor, swings with the show | Alternator with margin, oversized neutral | Seconds, but visible |
| Air conditioning and chillers for marquees | Large motors, compressors starting | Starting capacity, often a separate set | Minutes |
| Catering, vendors, temporary offices | Mixed resistive and small motor | Ordinary supply with residual current protection | Minutes |
| Emergency lighting, PA for announcements, CCTV | Small, life-safety | Independent supply or UPS | None |
Why electronic loads dislike generators
Stage and broadcast equipment is powered through switch-mode supplies and dimmers that draw current in short pulses rather than a smooth sine wave. On the grid this passes unnoticed, because the source impedance is tiny. On a generator, the same current distorts the alternator’s output voltage, and the equipment that caused the distortion is the equipment most upset by it: LED walls flicker, audio picks up hum, and video switchers reboot. The remedy is an alternator with a low sub-transient reactance and a rating margin for the nonlinear load, in practice a generator loaded to no more than 60 to 70 per cent by electronic equipment, a full-size or oversized neutral conductor to carry the third-harmonic current, and the air-conditioning compressors kept on a separate set so their starts do not reach the stage supply. The UPS and nonlinear load guide explains the alternator side, and a small online UPS on the consoles and broadcast chain covers the brief interruptions that even a good generator installation cannot rule out.
Redundancy for the loads that cannot fail
For a concert, televised event or a wedding where the ceremony is timed to the minute, the stage supply should not depend on one engine. The usual arrangement is two generators of equal rating feeding the stage distribution through a changeover panel, with the second set running at no load during the show so that the changeover takes seconds rather than the minute a cold start would need. For larger productions the two sets run synchronised in parallel so that a failure of either leaves the other carrying the load with no interruption at all, which is the only arrangement that is truly seamless. The generator-to-generator transfer page describes both schemes. Whichever is chosen, the changeover should be tested at the sound check, not discovered during the headline act.
Noise, exhaust and placement
Generators at events must be heard by nobody and reached by no one who should not. CPCB noise norms require diesel generators up to 1,000 kVA to be supplied in acoustic enclosures limited to 75 dB(A) at one metre, and event sites usually need better than that near the audience, which means placing the sets as far from the stage and seating as the cable run allows and orienting the exhaust and radiator discharge away from the public and from marquee air intakes. Exhaust contains carbon monoxide; a generator placed against a marquee wall with the exhaust discharging under the canvas edge is a known cause of illness at events. Fence the generator compound, keep the fuel store within it, and keep a fire extinguisher and spill kit at hand. The acoustic engineering guide covers attenuation at the source and along the path.
Distribution, earthing and public safety
Event distribution is a temporary low-voltage installation and must be treated as one under the CEA safety regulations. Every final circuit serving the public, vendors or crew should be protected by a 30 mA residual current device, the generator neutral must be earthed at the set with a driven electrode and a measured resistance, and all metal structures within reach, including stage scaffolding, trussing and barriers near cables, should be bonded to the same earth. Cables crossing public walkways go under cable ramps or overhead; cables near catering and wet areas need appropriate ingress protection. Before the public arrives, one person should walk the whole installation with the single-line diagram, test each residual current device and record the earth readings. The temporary distribution page lists the panel and cable arrangements that make this practical.
Fuel, runtime and responsibility
An event generator may run 18 hours a day for a week. A 125 kVA set at 60 per cent load uses roughly 18 to 20 litres an hour, so a three-day event with two sets needs well over 2,000 litres on site or a refuelling plan that does not involve a tanker crossing a crowded venue (illustrative). Agree in writing who may request additional load, who operates the sets, what the response is to an alarm, and when the installation is handed back; the rental and temporary power page describes the usual scope. The event manager should know the supported demand and the condition, such as a new vendor or a bigger LED wall, that requires the installation to be reviewed before it is connected.
Common mistakes
- Sizing the event from the sum of every connected item. The generator runs at 25 per cent load for the whole event and the hire cost and fuel are both higher than necessary.
- Putting the air-conditioning compressors on the same set as the stage. Every compressor start dips the voltage and the LED wall blinks on camera.
- Relying on one generator for a televised or ceremonial moment. A single fault stops the event in front of the audience with no recovery path.
- Leaving the generator neutral unearthed because the site is temporary. Residual current devices behave unpredictably and a damaged cable becomes a shock risk to the public.
- Parking the generator against the marquee with the exhaust under the canvas. Carbon monoxide enters the tent and people fall ill.
What to send us
Send the event programme with dates and daily hours, the equipment list for stage, lighting, screens, air conditioning and catering with their kW, and a site plan showing the stage, seating, marquees and where generators and cables can go. Tell us which loads must not fail, the noise constraints of the venue and whether broadcast is involved. Send your event power requirement.
Questions engineers ask
How many kVA does a wedding or corporate event need?
A marquee event for 500 guests with stage sound, lighting, LED screen and catering typically needs 60 to 125 kVA, and the air conditioning can double or treble that figure. The equipment list and the air-conditioning tonnage decide it, not the guest count.
Do events need two generators?
For stage, broadcast or any timed ceremony, yes, either on a tested changeover panel or synchronised in parallel. For catering, vendors and lighting that can tolerate a short break, a single set with a spare on call is usually acceptable.
What noise level should an event generator meet?
Enclosed sets are limited to 75 dB(A) at one metre under CPCB norms. A venue usually needs the set far enough from the audience that it is inaudible over the event itself, typically 30 metres or more with the exhaust facing away.
Why do LED walls flicker on generator power?
LED walls and dimmers draw distorted current that a generator’s alternator turns into distorted voltage, and the same equipment is sensitive to that distortion. An alternator loaded to no more than 60 to 70 per cent by electronic loads, a full-size neutral and separation from compressor starts usually cures it.
Technical content reviewed by Srinivas Reddy, Managing Partner, Reddy Generators. Last updated 19 October 2026.