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Homeowners & Builders: Gate Motor Power to Avoid 24V Voltage Drop

October 4, 2026
Homeowners & Builders: Gate Motor Power to Avoid 24V Voltage Drop

Most residential gate systems run a low-voltage motor, usually 24V, fed by a transformer connected to 230 to 240V mains power. Before you order a motor or ask an electrician for a quote, check three figures: the motor's voltage, the transformer's VA rating and the planned cable run. Mains connection work needs a licensed electrician and, in many cases, a Certificate of Electrical Safety.

TL;DR:

  • Use a transformer rated at least 150VA for an 80W motor, and allocate extra margin for starting current spikes during gate operation.
  • For gates more than 30 meters from the switchboard, consider running mains voltage directly to a transformer at the gate to prevent voltage drop issues.
  • Always size cable according to standards that account for voltage drop and short-circuit temperature rise, not just motor wattage, especially for long cable runs.
  • Ensure electrical work is performed by a licensed electrician and inspected within eight days to comply with safety regulations and obtain a certificate of safety.
  • Pre-wire conduit and outlets during civil works, including spare conduits for future accessories, to prevent costly trenching and rework after paving.
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Table of Contents

Typical power ratings explained: volts, watts, VA and amps

Manufacturer spec sheets throw several numbers at you, and they are not interchangeable. Volts measure electrical pressure, amps measure current flow, and watts measure the actual power being used: watts equal volts multiplied by amps. VA, or volt-amperes, is a related figure used for transformers and includes the reactive load that a motor's windings create, which is why a transformer's VA rating usually sits above the quoted motor wattage.

A gate motor spec typically separates several readings: mains input voltage and current, transformer VA output, motor operating voltage, motor wattage and the current draw of accessories like safety beams or an intercom. Manufacturer manuals often list a mains input of 230 to 240V AC, a transformer secondary of 24V AC rated at 150VA, and a 24V DC motor driving the gate itself.

A simple example: a 24V, 80W motor draws roughly 3.3A at the motor terminals during steady running. That is not the figure to use when sizing the mains circuit or the transformer, because starting current, which spikes briefly as the motor overcomes the gate's initial inertia, runs higher than the steady-state draw.

  • Watts = volts × amps, the formula behind every power rating on a spec sheet.
  • Mains input, transformer VA and motor voltage are separate numbers and need separate checks.
  • Starting current is higher than running current and should shape your cable and transformer choice, not just the quoted wattage.

24V versus 230 to 240V systems: which suits your gate

Most residential installers default to a 24V DC motor powered through a transformer wired to 230 to 240V mains. The low-voltage side is safer to work around, simpler to back up with a battery during a blackout, and matches the control architecture used by most residential controllers, safety beams and intercoms.

A mains-voltage operator, where the motor itself runs on 230 to 240V, suits a different set of conditions: heavy commercial or industrial gates with a high duty cycle, or sites where the gate sits close to the switchboard and a long low-voltage run would otherwise be needed. Running mains voltage further and transforming or converting it near the motor avoids the voltage-drop penalties that come with long low-voltage cable runs.

  • 24V systems handle battery backup more simply and keep the heavier mains wiring work closer to the house.
  • 230 to 240V operators suit high-cycle commercial gates where consistent torque under load matters more than battery backup.
  • Voltage drop affects 24V runs far more than mains runs for the same cable length, because the same power needs higher current at lower voltage.

Pro Tip: If your gate sits more than 20 to 30 metres from the switchboard, ask your installer whether running mains power to a transformer near the gate beats a long low-voltage cable run.

Wiring, cable sizing and voltage drop: avoiding unreliable starts

Illustration of voltage loss along cable

Cable sizing for a gate motor circuit is not just a matter of matching current-carrying capacity. AS/NZS 3008.1.1 sets out methods for selecting cable based on current-carrying capacity, voltage drop and short-circuit temperature rise, and all three matter for a gate circuit that sees a startup current spike every time the gate opens.

AS/NZS 3000 sets a maximum voltage drop guideline of 10% of nominal voltage for extra-low-voltage circuits under normal operating current, and that figure excludes the brief transient spike at motor start.

  1. Calculate the circuit's steady-state current from the motor's wattage and voltage, then add margin for starting transients.
  2. Apply AS/NZS 3008.1.1 methods to select a conductor size that keeps voltage drop under the 10% guideline over the full cable run.
  3. For long runs, consider a larger conductor, moving the transformer closer to the gate, or running mains voltage to a transformer sited at the gate instead.

Electricians calculate this from actual current, cable route, conductor size and run length rather than sizing from motor wattage alone, since that figure says nothing about the voltage drop a long low-voltage cable will introduce.

Long runs and alternative supply strategies

When the gate sits well away from the switchboard, you have two broad options: run low-voltage cable all the way to the motor, or run mains voltage to a transformer positioned at the gate itself. The second option sidesteps voltage-drop problems on long runs, since mains voltage tolerates distance far better than 24V does for the same power delivered.

Battery backup is worth planning early if the property loses power occasionally. Estimate the backup capacity from how often the gate cycles per day and the accessory loads it carries, such as beams, an intercom or lighting, since each cycle and each accessory draws from the same battery reserve.

  • Running mains to a gate-side transformer avoids the voltage-drop penalty of a long 24V cable run.
  • Battery backup sizing depends on daily cycle count and any accessories wired into the same circuit.
  • Solar or a generator can supplement backup power on sites without reliable mains access, and both are worth raising with your installer at the design stage rather than after installation.

Site planning and pre-wiring checklist for builders and homeowners

Power decisions belong in the civil works stage, not after the driveway is paved. A conduit laid in the wrong spot, or without spare capacity, means trenching through finished paving later to add a safety beam or intercom cable.

  • Lay conduit along the planned cable route before paving, with a weatherproof outlet location agreed in advance.
  • Include at least one spare conduit for safety beams, intercoms or future accessories you have not wired yet.
  • Confirm the outlet or transformer location with your electrician and gate installer before the trench is filled.

Pro Tip: Ask your electrician and gate installer to agree on conduit routing together, on site, before any concrete or paving goes down.

The most common on-site mistake is treating the gate motor as an afterthought in the electrical plan, which leaves installers running surface-mounted cable or compromising on transformer placement because the conduit never reached the right spot.

Electrician routing conduit for gate motor

Safety, compliance and the Certificate of Electrical Safety

Electrical installation work connected to a gate motor is frequently classed as prescribed work, and prescribed work must be inspected by a licensed electrical inspector before it is connected to supply. The property owner, or whoever commissions the work, is typically the Responsible Person and carries the obligation to arrange that inspection.

Under the relevant guidance, prescribed electrical installation work must be inspected within eight days of completion and before the circuit is energised, with the Responsible Person arranging both the inspection and the compliance paperwork.

  • Confirm whether your gate's electrical work falls under prescribed or non-prescribed categories before work starts.
  • Ask your electrician who holds the Responsible Person obligation for your installation.
  • Request the Certificate of Electrical Safety and inspection records once the work is complete, and keep them with your property documents.

How to read a gate motor specification sheet

A spec sheet is only useful once you know which lines matter. Before comparing two motors, pull out the mains input voltage and current, the transformer's VA rating, the motor's voltage and wattage, any accessory current draw, the starting current if listed, and the duty cycle rating.

  1. Record the mains input line (typically 230 to 240V AC) and its rated current.
  2. Record the transformer's VA output and the motor's own voltage and wattage separately.
  3. Add up accessory loads, such as beams or an intercom, that share the same transformer or controller.
  4. Check the duty cycle rating against how often the gate will actually cycle each day.

A worked example shows why this matters: a motor rated at 24V and 80W draws about 3.3A at the motor, but the transformer behind it might be rated at 150VA to cover starting current and accessory draw, and the mains side pulls well under 1A at 230 to 240V because of the voltage difference. Red flags on a spec sheet include a transformer VA rating close to the motor's steady wattage, which leaves little margin for starting current, and a missing duty cycle figure, which makes it hard to judge whether the motor suits a gate that cycles often.

What installers notice that spec sheets do not show

Spec sheets tell you the numbers; they rarely tell you where the pain points show up on site. The gap between a motor's rated figures and a reliable installation usually comes down to planning done weeks before the motor arrives: conduit routed to the right spot, a weatherproof outlet placed within reach of the controller, and enough spare conduit that a safety beam added later does not mean new trenching.

The most common oversight we see is a homeowner choosing a motor based on gate weight alone, without checking how far the transformer will sit from the switchboard or whether the site needs mains run to the gate instead. Getting the electrician, builder and gate installer talking before the trench is dug avoids most of the rework we get called back for.

— Rhys

Getting your gate motor specified, supplied and installed correctly

Working out the right transformer VA, cable size and conduit layout is easier with someone who does this daily. A local company designs and fabricates custom gates in-house from quality materials, and coordinates the electrical specification with your electrician from the design stage through to certified installation.

Vicgates

Our automation and access control service covers controller, safety beam and intercom supply alongside the gate motor itself, and we work with your builder and electrician to settle conduit routing and outlet placement before the civil works lock it in. For larger or higher-cycle sites, our commercial and industrial team handles the heavier duty-cycle requirements a mains-voltage operator demands. If you are weighing up access control integration alongside your gate, a specialist like Tawy Systems covers the intercom and access-control side of the electrics that often shares a circuit with the gate motor.

If you are ready to plan your gate's power requirements properly, request a design consult and we will walk through the site, the motor options and the compliance steps with you.

FAQ

How many amps does a gate motor use?

A typical 24V, 80W residential gate motor draws roughly 3.3A at the motor itself during steady running, though starting current runs higher for a brief period. The mains side of the same system draws far less current because it runs at 230 to 240V rather than 24V.

What are the electrical power requirements for an automatic gate opener?

Most residential openers need a 230 to 240V mains supply feeding a transformer, which steps down to a 24V DC motor circuit, plus a weatherproof outlet near the installation point. Manufacturer manuals commonly call for a 240V, 10A outlet within one metre of the opener for installation and servicing.

How many watts does a gate opener use?

Residential gate motors commonly sit in the tens of watts range, with an example 24V motor rated around 80W, though the figure varies by gate size, weight and how often it cycles. The transformer feeding that motor is usually rated well above the motor's wattage, such as 150VA, to allow for starting current and any connected accessories.

What are the wiring requirements for an electric gate?

Cable for a gate motor circuit needs to be sized using AS/NZS 3008.1.1 methods, which account for current-carrying capacity and voltage drop, not just a simple amp rating. Mains connection work is generally prescribed electrical work, meaning it needs a licensed electrician and inspection before connection.

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