Power Management: Balancing 3-Phase Loads for Multi-Booth Circuits

A multi-booth exhibition can involve dozens of screens, LED displays, laptops, lighting fixtures, speakers, charging stations and interactive technologies operating simultaneously. While much of the planning focuses on booth design and visitor experience, one technical area can easily be overlooked: power distribution.

For an exhibition with multiple booths, simply having enough total electrical capacity does not automatically mean the system is properly designed. The way loads are distributed across the available phases can affect circuit utilisation, voltage stability, equipment reliability and the likelihood of nuisance breaker trips.

This becomes especially important when an event uses substantial audio visual equipment rental, including LED screens, displays, projectors, sound systems, media servers, computers, lighting and other powered equipment across several booths.

Three-phase power distribution provides a practical way to handle larger electrical requirements, but it needs to be planned rather than treated as a single pool of available power. The objective is to distribute the expected loads as evenly as reasonably possible across the three phases while maintaining appropriate protection, cable capacity and venue requirements.

So, how does three-phase load balancing work in an exhibition environment, and what should event organisers and technical teams consider before connecting multiple booths?

What Is 3-Phase Load Balancing?

A three-phase electrical system consists of three alternating voltage phases, commonly referred to as L1, L2 and L3. In a balanced system, the connected loads are distributed so that the current drawn by each phase is reasonably similar.

Three-phase load balancing therefore means arranging electrical loads across the three phases rather than allowing one phase to carry substantially more demand than the others.

The principle is straightforward.

Imagine an exhibition has three groups of booths:

• Booth Group A draws approximately 20 A.
• Booth Group B draws approximately 19 A.
• Booth Group C draws approximately 21 A.

This represents a relatively balanced distribution.

Now imagine the same total requirement is distributed as:

• L1: 35 A
• L2: 15 A
• L3: 10 A

The total current may appear manageable when viewed as one number, but the individual phase loading is very different.

That difference matters because the electrical system is limited by the capacity of its individual components and circuits, not simply by the sum of all connected equipment.

Three-phase load balancing is therefore an important part of power planning for larger exhibitions, conferences, roadshows and event productions. Industry guidance on three-phase systems highlights that unbalanced loads can reduce efficiency, increase the possibility of circuit protection operating, and reduce equipment service life.

Why Does Load Balancing Matter at Exhibitions?

An exhibition floor can create a particularly complicated electrical environment.

Unlike a single corporate presentation where the equipment list may be relatively predictable, a multi-booth exhibition can involve many independent electrical loads operating at different times.

One exhibitor may use a large LED display continuously.

Another may have several televisions, laptops and charging points.

A third may operate an interactive touchscreen installation.

Another booth may have decorative lighting, a small sound system and a product demonstration.

There may also be common-area requirements such as registration counters, digital signage, networking equipment, production control, speaker systems and venue infrastructure.

This makes power planning more than simply adding the wattage of every device.

1. Avoiding Overloaded Individual Phases

The first objective is to prevent one phase from becoming heavily loaded while the other phases remain comparatively lightly loaded.

If too many single-phase circuits are connected to the same phase, that phase can approach its circuit or distribution capacity even though substantial capacity remains available on the other phases.

Proper distribution makes better use of the available electrical infrastructure.

2. Reducing Voltage Drop Problems

High current through cables produces voltage drop. When a particular circuit or phase is heavily loaded, voltage performance can become more difficult to manage, particularly where cable runs are long.

This is relevant in exhibitions because distribution boards may be positioned some distance from booths.

Long cable runs, temporary distribution equipment and high-demand loads should therefore be considered together during planning.

3. Reducing Nuisance Trips

A breaker trip during an exhibition is more than a technical inconvenience.

If the affected circuit powers a booth’s LED display, media player, touchscreen or product demonstration, the exhibitor may immediately notice the interruption.

If the circuit supports shared production equipment, the impact can be much greater.

Balanced loading does not eliminate every possible cause of a breaker trip, but it reduces the risk associated with poorly distributed electrical demand.

4. Improving Equipment Reliability

Modern event technology contains sensitive electronic equipment, including processors, power supplies, computers, LED controllers and networking devices.

Stable electrical conditions are therefore important.

Three-phase load balancing is one part of maintaining a properly planned power distribution system. Sunbird notes that balanced three-phase power can improve infrastructure utilisation and support equipment reliability, while unbalanced systems can reduce efficiency and create operational problems.

What Makes Multi-Booth Power Different?

The main challenge is that exhibition booths are not electrically identical.

Consider a simple example.

Booth A – Corporate Display

• 2 × commercial displays
• 1 × media player
• 4 × laptops
• LED lighting
• Charging outlets

Estimated demand: relatively low.

Booth B – Product Launch

• Large LED display
• Media server
• Multiple lighting fixtures
• Sound system
• Demonstration equipment
• Several computers

Estimated demand: significantly higher.

Booth C – Interactive Experience

• LED display
• Touchscreen systems
• Computers
• Sensors
• Networking equipment
• Lighting

Estimated demand: moderate but continuous.

If these loads are assigned without considering the phase distribution, the electrical system may become unbalanced.

The challenge becomes even greater when several high-demand exhibitors are positioned close together and share a common temporary distribution arrangement.

This is why audio visual equipment rental should not be considered separately from power planning.

When an AV supplier is involved early, the equipment list can be translated into an electrical load schedule before the installation begins.

Start With an Equipment Load Schedule

One of the most useful steps in exhibition power planning is creating a load schedule.

Instead of simply listing equipment, identify the estimated electrical demand of each item or equipment group.

A basic schedule might contain:

Equipment	Quantity	Estimated Load	Booth
LED Display	1	Manufacturer specification	A
Commercial Display	2	Manufacturer specification	B
Media Server	1	Manufacturer specification	B
Laptop	4	Estimated/actual specification	A
Touchscreen	2	Manufacturer specification	C
Lighting Fixtures	8	Manufacturer specification	C
Audio System	1 set	System specification	B

The important point is that the figures should come from actual equipment specifications wherever possible.

Do not assume that every piece of equipment consumes the maximum theoretical rating continuously. At the same time, do not underestimate the requirement simply because the equipment normally operates below its maximum rating.

The technical team should consider both expected operating load and relevant peak or startup characteristics.

From Wattage to Current

For single-phase equipment, a simplified relationship is:

Current (A) = Power (W) ÷ Voltage (V)

For example, a 1,000 W load operating at 230 V would draw approximately:

1,000 ÷ 230 = 4.35 A

This is only a simplified calculation. Actual current can differ depending on power factor, equipment design and operating conditions.

For three-phase systems, the relationship is different. A commonly used simplified formula for balanced three-phase power is:

P = √3 × V × I × Power Factor

Where:

• P = power in watts
• V = line-to-line voltage
• I = line current
• √3 ≈ 1.732
• Power Factor = relationship between real and apparent power

Event technicians should use the actual electrical characteristics and venue requirements rather than relying on simplified calculations when designing a live distribution system.

The calculations provide a planning foundation, but the final distribution should be verified by a qualified electrical professional.

Apparent Power: Why kVA Matters

Another important concept is apparent power.

Electrical systems are often discussed using:

• Watts (W)
• Kilowatts (kW)
• Volt-amperes (VA)
• Kilovolt-amperes (kVA)
• Amperes (A)

For many electronic systems, the relationship between real power and apparent power is affected by power factor.

This matters when evaluating the capacity of electrical distribution equipment.

An AV system might have a relatively modest real power consumption but still present a different apparent-power requirement depending on its power supplies and power factor.

This is one reason technical teams should review actual equipment specifications rather than simply adding nominal wattages.

For complex audio visual equipment rental projects, the equipment schedule should ideally be converted into a practical electrical load schedule that the electrical and venue teams can use.

How Do You Balance Three Phases?

Once the expected loads are known, they can be distributed across L1, L2 and L3.

Imagine an exhibition has six booth circuits with estimated loads:

• Booth 1: 8 A
• Booth 2: 10 A
• Booth 3: 6 A
• Booth 4: 9 A
• Booth 5: 7 A
• Booth 6: 11 A

Instead of assigning the first three booths to L1 and the remaining three to L2 and L3 without calculation, the technical team can arrange the loads to produce a more even result.

For example:

L1: 8 A + 7 A = 15 A
L2: 10 A + 6 A = 16 A
L3: 9 A + 11 A = 20 A

This is not perfectly equal, but it is much more controlled than randomly assigning circuits.

The actual acceptable loading depends on the distribution equipment, protective devices, cable ratings, venue requirements and electrical design.

The goal is not simply to achieve mathematically identical numbers. It is to maintain a safe and practical distribution within the limits of the installed system.

The Role of Distribution Boards

Temporary distribution boards are often the centre of event power management.

A properly planned distribution arrangement can divide the incoming supply into separate circuits for different booths, AV systems and production areas.

A typical event power arrangement may involve:

Venue Supply → Main Distribution → Temporary Distribution → Booth Circuits → Equipment

Each stage has its own capacity and protection requirements.

The distribution board should therefore not be treated as a box where cables are simply plugged in.

Its configuration needs to consider:

• Incoming supply capacity
• Phase allocation
• Circuit ratings
• Protective devices
• Cable capacity
• Earth protection
• Neutral requirements
• Load diversity
• Physical cable routes
• Equipment connection requirements
• Venue regulations

For exhibition work, documentation is particularly useful because changes can happen during build-up.

A booth may add another display.

An exhibitor may request additional lighting.

A product demonstration may introduce new equipment.

If the original power schedule is not updated, the actual installation can gradually move away from the planned load distribution.

Why LED Screens Require Attention

LED screens are an important consideration in modern exhibitions because they can represent a significant electrical load depending on their size, technology, brightness and operating conditions.

A large LED wall should therefore not be treated as simply another display.

The technical team should review the manufacturer’s electrical specifications and consider:

• Screen size
• Pixel pitch
• Module configuration
• Maximum power consumption
• Typical power consumption
• Processing equipment
• Control systems
• Brightness settings
• Operating schedule
• Distribution arrangement

The same principle applies to large displays, projection systems and other visual equipment.

Professional audio visual equipment rental is not simply about selecting equipment with the right image quality. The equipment must also be integrated into the venue’s technical infrastructure.

Don’t Forget Audio Systems

Audio systems can also contribute to the electrical load.

A larger exhibition may include:

• Powered loudspeakers
• Subwoofers
• Digital mixing consoles
• Amplifiers
• Wireless microphone receivers
• Audio processors
• Playback computers
• Stage monitors

A small booth might use a compact powered speaker, while a central stage could require a substantially larger sound system.

These loads should be included in the electrical plan rather than being added at the final installation stage.

DOREMi’s current AV rental information highlights that larger events may combine LED screens, professional sound systems, stage lighting, video systems and technical coordination, making system integration an important part of AV planning.

Lighting Can Change the Load Schedule

Lighting is another area where assumptions can cause problems.

A booth may have:

• LED spotlights
• Profile fixtures
• Wash fixtures
• Decorative lighting
• Display lighting
• Moving lights
• Special effects

While modern LED fixtures can be relatively efficient, a large number of fixtures can still create a meaningful electrical demand.

Lighting also tends to be used differently from equipment such as laptops.

Some fixtures may only operate during presentations or demonstrations, while others remain active throughout the exhibition.

This difference between connected load and actual operating load should be considered when planning the overall system.

Consider the Timing of Loads

A good power plan does not only ask:

“How much equipment is connected?”

It also asks:

“When will that equipment operate?”

For example, a booth might use a large presentation system only during scheduled demonstrations.

A central stage might activate additional lighting and sound equipment during keynote sessions.

Several exhibitors might simultaneously begin product demonstrations at a particular time.

This creates a temporary increase in demand.

Therefore, event power planning should consider the event programme as well as the equipment list.

This is especially important for exhibitions where multiple booths have different operating schedules.

Power Distribution Is Also About Physical Layout

Electrical planning should follow the actual floor plan.

The technical team should know:

• Location of venue supply points
• Position of distribution boards
• Booth locations
• Cable routes
• Equipment positions
• Stage locations
• Production areas
• High-demand equipment
• Emergency access routes

A technically balanced load can still create an impractical installation if cables need to travel excessive distances or cross unsuitable areas.

Cable management therefore forms part of power management.

Cable routes should be planned to minimise hazards, protect cables from physical damage and maintain safe access around booths.

Monitoring the Load During Build-Up

Calculations made before the event are important, but measurements during installation can provide another level of assurance.

Power monitoring equipment can be used to observe phase currents and identify differences between L1, L2 and L3.

Electrical Trader recommends measuring phase loads and monitoring the system rather than relying solely on initial assumptions. Its three-phase load-balancing guidance also highlights power quality analysers and smart meters as useful tools for identifying imbalances.

For a major event, technicians may monitor the system during:

1. Initial energisation
2. Equipment installation
3. Technical rehearsal
4. Peak event operation
5. Major programme changes

This can reveal unexpected behaviour that was not obvious from the original equipment schedule.

What Happens When Loads Are Poorly Balanced?

An unbalanced system does not necessarily fail immediately.

That is what makes the problem difficult to identify.

Instead, the system may experience gradual symptoms such as:

• Uneven phase current
• Increased heating
• Voltage variation
• Reduced available capacity on one phase
• Nuisance protective-device operation
• Reduced system efficiency
• Greater stress on equipment
• Unexpected interruptions

Sunbird explains that unbalanced three-phase loads can reduce efficiency and power delivery, while balanced systems make better use of upstream infrastructure capacity.

For an exhibition, the consequences can be particularly disruptive because the equipment is supporting a live customer-facing environment.

A booth going offline during a product demonstration is immediately visible.

Common Power Planning Mistakes at Multi-Booth Events

Treating Total Capacity as the Only Number

Having enough total kVA does not automatically mean the individual phases and circuits are correctly loaded.

Adding Equipment Without Updating the Schedule

Last-minute additions should be reflected in the electrical load plan.

Forgetting Support Equipment

Media servers, processors, laptops, networking devices, chargers and control equipment all contribute to the electrical requirement.

Assuming All Equipment Has the Same Operating Pattern

Some equipment operates continuously, while other systems are active only during demonstrations or presentations.

Ignoring Cable Length

Long cable runs can introduce voltage-drop considerations and physical installation challenges.

Randomly Assigning Booths to Phases

Phase allocation should be deliberate rather than based purely on convenience.

Leaving Power Planning Until Build-Up

By the time equipment is being installed, major distribution decisions may already have been made.

Power requirements should ideally be discussed during the technical planning stage.

A Practical Multi-Booth Power Planning Process

A structured process can make the entire operation easier.

Step 1: Collect the Equipment List

Obtain the complete equipment requirements from every booth and production area.

Step 2: Identify Electrical Specifications

Record voltage, current, wattage, kVA and other relevant information from equipment documentation.

Step 3: Group the Loads

Separate equipment by booth, production area, stage, registration, lighting and other functions.

Step 4: Identify High-Demand Equipment

Highlight large LED systems, powerful audio systems, lighting systems and other significant loads.

Step 5: Create a Phase Schedule

Distribute the circuits across L1, L2 and L3 with the objective of keeping the loading reasonably balanced.

Step 6: Check Distribution Capacity

Verify that distribution boards, protective devices, cables and venue supply arrangements can support the planned loads.

Step 7: Confirm With the Venue

Exhibition centres and convention venues may have specific electrical requirements, approved connection points and procedures for temporary distribution.

Step 8: Test Before the Event

Energise and test the system before the exhibition opens.

Step 9: Monitor During Peak Operation

Observe the system when the largest combination of equipment is operating.

Step 10: Document Changes

If circuits or equipment change during build-up, update the final distribution documentation.

Why Early AV Planning Makes a Difference

Power management should not be separated from AV planning.

A professional AV system involves multiple interconnected components. DOREMi’s AV services, for example, cover displays, projectors, professional sound systems, lighting, live streaming and larger integrated AV systems.

When the AV equipment list is known early, the technical team can consider:

Equipment → Power Requirement → Distribution → Cable Route → Position → Operation

This approach is much more reliable than installing the equipment first and solving the power requirements afterward.

For audio visual equipment rental, this is particularly important when several booths are being supported by the same technical provider.

The rental provider may already know the equipment specifications, quantities and intended operating positions. That information can be incorporated into the power schedule before the installation begins.

How Audio Visual Equipment Rental Providers Can Support Power Planning

When selecting an audio visual equipment rental provider for a multi-booth exhibition, clients should look beyond the equipment catalogue.

Ask whether the provider can support:

• Equipment load documentation
• Technical planning
• Power requirement calculations
• Distribution coordination
• Equipment placement
• Cable management
• Technical rehearsal
• On-site technical support
• Backup planning

This is particularly important for exhibitions where several systems need to operate together.

DOREMi describes its AV rental services as supporting venue planning and customised arrangements, while its wider event production services include technical aspects such as audiovisual systems, lighting, projection, staging and rigging.

The objective is not necessarily for the AV provider to replace the venue’s electrical contractor or qualified electrician. Instead, the AV team should provide accurate equipment information and coordinate closely with the electrical professionals responsible for the temporary power installation.

Safety Comes Before Load Optimisation

Three-phase load balancing is an engineering and electrical-safety subject.

Event organisers should not attempt to reconfigure live electrical distribution themselves.

The final installation should follow applicable Malaysian electrical requirements, venue rules, equipment specifications and the instructions of qualified electrical personnel.

Load balancing is only one part of a safe electrical system.

The complete design also needs to consider:

• Correct cable sizing
• Protective devices
• Earthing
• Residual-current protection where applicable
• Distribution equipment
• Connector ratings
• Cable protection
• Environmental conditions
• Emergency isolation
• Venue requirements

The calculations in this article are intended to explain the planning concept, not to replace a professional electrical design or site-specific assessment.

A Simple Checklist for Multi-Booth Power Planning

Before an exhibition opens, confirm:

Equipment

• Complete AV equipment list available
• Equipment specifications checked
• High-demand equipment identified
• Additional booth equipment accounted for

Load Planning

• Estimated loads calculated
• L1, L2 and L3 allocation prepared
• Phase loading reviewed
• Distribution capacity verified

Installation

• Distribution boards positioned correctly
• Cable routes planned
• Cables protected and managed
• Connections checked
• Venue requirements followed

Testing

• Phase currents measured
• Equipment energised and tested
• High-load operating scenarios checked
• Technical rehearsal completed
• Changes documented

During Event

• Technical team available
• Critical systems monitored
• Spare equipment or contingency arrangements prepared
• Unplanned equipment additions controlled

Frequently Asked Questions

What is three-phase load balancing?

Three-phase load balancing is the process of distributing electrical loads as evenly as reasonably possible across three phases, commonly identified as L1, L2 and L3. Proper distribution helps utilise the available electrical infrastructure more effectively and can reduce problems associated with heavily loaded individual phases.

Why is three-phase load balancing important for exhibitions?

Exhibitions can involve many independent electrical loads operating simultaneously, including LED screens, displays, lighting, computers, sound systems and interactive technology. Balancing these loads helps prevent excessive demand from being concentrated on one phase.

Does every booth need its own phase?

No. A booth does not necessarily require an entire electrical phase. Multiple booth circuits can be distributed across the available phases depending on the venue’s electrical design, circuit capacity and the equipment requirements.

Does LED screen rental affect power planning?

Yes. LED screens can represent a significant electrical load depending on their size, specification, brightness and operating conditions. Their electrical requirements should be included in the overall load schedule.

Can an AV rental company handle the electrical installation?

This depends on the project and the responsibilities defined by the venue and contractors. AV providers can supply equipment specifications, estimated loads and technical coordination, but electrical installation and modification should be carried out by appropriately qualified electrical professionals in accordance with applicable requirements.

What information should I give an AV rental company?

Provide the event floor plan, booth locations, equipment requirements, event schedule, venue details and any available electrical information. The earlier this information is shared, the easier it is to coordinate the AV system and power requirements.

How can I reduce the risk of power problems during an exhibition?

Start power planning early, create an equipment load schedule, distribute loads carefully, verify the capacity of the electrical infrastructure, test the system before opening and monitor important circuits during peak operation.

Further Reading

3-Phase Load Balancing Techniques Explained — Electrical Trader: practical information on measuring phase loads, manual phase swapping, monitoring and three-phase balancing. Electrical Trader – 3-Phase Load Balancing Techniques Explained

Three-Phase Load Balancing — Sunbird DCIM: explanation of three-phase load distribution, efficiency, capacity utilisation and monitoring. Sunbird DCIM – Three-Phase Load Balancing