Dedicated Circuits for Powering Heavy Tools in Workshops

If you own a shed on a rural property and are considering transforming it into a fully functional workshop, paying attention to the electrical setup is crucial.
Using a MIG welder, air compressor, and table saw on the same circuit as your home can lead to significant issues, including tripped breakers, flickering lights, and potentially hazardous overload situations.

This comprehensive guide explains the essentials of wiring a robust workshop in rural areas of the Mid North Coast. We’ll discuss dedicated circuits, sub-boards, and three-phase power for larger machinery. If your needs are limited to basic shed power—like lighting and a few outlets—refer to our guide on Shed Wiring on Acreage for a more suitable starting point. This article is tailored for workshops that demand serious power.

Understanding the Importance of Dedicated Circuits

Most residential properties operate multiple power points on shared circuits, which is adequate for low-power devices like kettles and TVs. it becomes problematic when you attempt to operate a 32-amp MIG welder and an air compressor simultaneously.

Here’s what can occur when you connect heavy machinery to house circuits:

• Frequent tripped breakers — A welder drawing over 30 amps on a 20-amp circuit will trip the breaker immediately or, worse, cause the wiring to overheat before the breaker activates.
• Voltage drops — Long cable runs from the main board to the shed result in voltage sag. This can cause your tools to operate hotter, slower, and degrade more quickly.
• Power disruptions in the house — Your partner may lose power in the kitchen because you started the compressor. This situation often leads to unwelcome discussions.
• Increased fire hazards — Overloaded wiring within walls and cable runs is a significant cause of electrical fires in rural areas.

Dedicated circuits effectively eliminate these issues. Each heavy tool receives its own circuit, appropriately sized for its load, along with its own breaker protection. This means nothing is shared, and nothing gets overloaded.

Power Consumption of Common Workshop Equipment

Before your electrician can create a circuit layout, you need to understand your equipment’s power requirements. Here’s a breakdown of the typical power draws for common workshop tools:

• MIG welder — Requires between 15A and 32A based on the model. Larger 240V welders tend to be at the higher end. Three-phase units have different requirements (more on that later).
• Air compressor — Draws about 10A to 15A. The startup surge can be significant—compressor motors often pull 3 to 4 times their running current for a few seconds when starting up.
• Table saw — Typically uses 10A to 15A for a quality cabinet saw. Less expensive contractor saws may require less power, but you’re not here for a budget option.
• Lathe (wood or metal) — Similar to table saws, these generally require between 10A and 15A, with metal lathes usually being on the higher end.
• Dust extractor — Approximately 10A for a single-phase unit. It must run continuously while using other tools, so it should be on its own circuit.
• Plasma cutter — Draws between 20A and 30A, similar to a welder, and also requires a dedicated circuit.

When you sum up the total power draw, it becomes evident that a single 20-amp circuit from the house will not suffice. A well-equipped workshop can easily require 80 to 100+ amps across all circuits when operating at full capacity.

Selecting the Right Circuit Breaker Size and RCD Protection

Each circuit in your workshop must have a breaker that matches the cable size and anticipated load. Your electrician will calculate this based on your equipment, but as a general guideline:

• 15A or 20A circuits — Suitable for general power points, dust extractors, lighting circuits, and lighter tools.
• 32A circuits — Necessary for welders, plasma cutters, and other heavy single-phase machinery.
• Three-phase breakers — Sized according to the specific equipment requirements (details below).

RCD protection is essential. Under AS/NZS 3000 (the Australian Wiring Rules), all power and lighting circuits must have RCD (safety switch) protection. This requirement is not optional; it’s a legal mandate designed to safeguard against the high-risk nature of workshop environments.
Concrete floors, metal tools, dust, and moisture increase the likelihood of earth faults. RCDs instantly cut power if a current leak to earth occurs, which can be the difference between a minor shock and a hospital visit.

Typically, your electrician will implement a combination of RCDs and MCBs (miniature circuit breakers), or RCBO units that integrate both functionalities. RCBOs are particularly beneficial in workshops because a fault on one circuit does not disrupt power to the others.

Installing a Dedicated Sub-Board for Your Workshop

Instead of running multiple individual cables back to the main switchboard, installing a dedicated sub-board in your workshop is a smarter approach. Here are the advantages:

• Shorter cable runs — One heavy feed cable connects from the house (or a separate meter) to the workshop board, followed by shorter runs from the sub-board to each outlet. This reduces voltage drop and lowers cable expenses.
• Simplified fault diagnosis — Each circuit is clearly labelled and easily accessible in the workshop. If a breaker trips, you won’t need to trek back to the house to reset it.
• Future expansion — A properly sized sub-board allows for additional circuits in the future, making it simple to add new tools later.
• Isolation capability — You can turn off all workshop power from a single main switch without impacting the house's electricity.

If your house switchboard is outdated or operating at full capacity, you may need an upgrade before effectively powering the workshop sub-board. Older ceramic fuse boards may not safely handle the increased load.

A typical workshop sub-board setup includes a main switch, individual RCBOs for each circuit, a dedicated lighting circuit, and a surge protection device. We will size the incoming feed cable based on the total expected load plus a buffer for future additions.

Ensuring Proper Lighting in Your Workshop

Adequate lighting is essential for safety. You need to clearly see your work, especially around sharp blades and hot materials. Here are some key lighting considerations:

• High-lumen LED battens — LED panels or battens provide bright, even illumination throughout the space. Aim for a minimum of 500 lux at bench height.
• Dust-proof fittings — Standard lights can become clogged with sawdust and metal shavings. Choose IP-rated fittings that are dust and moisture resistant for longevity and safety.
• Task lighting at workstations — While overhead lighting covers the general area, focused lighting at the workbench, lathe, and drill press is crucial for precision work.
• Separate lighting circuit — Lighting should operate on its own circuit, ensuring that you still have light if a power circuit trips. Being left in the dark next to a running table saw is a safety risk.

We have extensive experience with lighting layouts in commercial spaces. Our team can assist you in creating a workshop lighting plan that significantly enhances your working environment.

Planning for Ventilation and Dust Extraction Circuits

When engaging in woodworking or welding, ensuring proper ventilation is as critical as having sufficient power. Dust extraction systems and exhaust fans require their own dedicated circuits because:

• Continuous operation — Your dust extractor must run whenever you’re cutting. It cannot share a circuit with the tool it serves.
• Motor startup loads — Dust extraction fans and collectors experience significant startup surges, similar to compressors.
• Interlocked switching — In an optimally designed workshop, the dust extractor can be wired to activate automatically when certain tools are powered on. This requires careful circuit design.

Plan for at least one dedicated 15A circuit for dust extraction and another for general ventilation. If you’re using a cyclone-style dust collection system, it might require a 20A circuit based on the motor specifications.

Utilising Three-Phase Power for Heavy Equipment

When you delve into intensive metalwork or operate large compressors (5HP+) or commercial-grade woodworking machinery, single-phase power may reach its limits. Three-phase power offers several advantages:

• Increased power capacity — Three-phase motors are more efficient and provide greater power without the excessive startup surges associated with single-phase motors.
• Support for larger welders and plasma cutters — Industrial MIG/TIG welders and CNC plasma tables typically operate on three-phase power.
• Smoother operation — Three-phase motors function more smoothly and run cooler, extending the lifespan of your tools.

Accessing three-phase power in rural locations on the Mid North Coast depends on availability at the street level. Some properties already have three-phase supply, while others may require a phase converter or a new connection from Essential Energy.
For more details, refer to our guide on Do I Need Three-Phase Power on My Property?

If three-phase power is accessible, your workshop will need an installation of a three-phase switchboard with appropriately rated breakers and an effective earthing system.

Implementing Surge Protection for Your Equipment

Tools equipped with electronic controls, variable frequency drives (VFDs), digital displays, and inverter welders are susceptible to voltage spikes. Notably, your workshop generates surges every time a large motor starts or stops. Coupled with the voltage instabilities often found in rural power lines, your equipment is at risk.

Installing a surge protection device (SPD) at the sub-board can intercept voltage spikes before they affect your tools. This is a cost-effective measure compared to replacing the electronic components of a $3,000 welder or CNC controller.

If your property is prone to storms (which is common on the Mid North Coast), we recommend adding surge protection at the main switchboard to safeguard against lightning-induced surges.

For properties that depend on a generator for backup power, incorporating a generator changeover switch ensures smooth transitions between mains power and generator supply without risking back-feeding or damaging connected equipment.

Additional Considerations for Your Workshop Fit-Out

Here are a few more elements to incorporate into your workshop wiring from the outset:

• Ample power points — Install more power points and switches than you anticipate needing. Use weatherproof GPOs if the workshop is open-sided. Consider double power points at every bench and outlets at key machinery locations.
• Data and communications — If you require internet access for streaming music, operating a CNC machine, or monitoring security cameras, plan for data and TV wiring concurrently with the electrical setup. It is significantly simpler to run cables during the initial fit-out than after the walls are finished.
• External lighting — Include floodlights outside the workshop to facilitate access during early mornings and late evenings, especially in rural areas lacking street lighting.
• EV or equipment charging — If you’re using electric equipment (battery-powered tools, an electric vehicle, or an electric quad bike), implement a dedicated charging circuit to prevent overloads on general outlets.

Estimating the Cost of Your Workshop Electrical Fit-Out

Cost estimates will vary based on workshop size, the number of circuits required, and whether three-phase power is necessary. As a rough guideline for the Mid North Coast:

• Basic single-phase setup (sub-board, 4–6 circuits, lighting) — Starting from $5,000
• Complete dedicated sub-board (8–12 circuits, multiple heavy tool circuits, dust extraction, comprehensive lighting design) — Starting from $10,000
• Three-phase workshop build (three-phase supply, dedicated board, heavy equipment circuits, complete fit-out) — Starting from $15,000+

These figures represent starting points. Complex layouts, lengthy cable runs from the mains, or the necessity for upgrades from Essential Energy will increase costs. We provide transparent quotes based on your specific workshop and equipment needs—no hidden fees.

Important Reminder — All Electrical Work Must Be Conducted by Licensed Professionals

This is a critical point. In New South Wales, all electrical wiring work must be performed by a licensed electrician. This includes installing new circuits, sub-boards, power points, and connecting equipment. There is no DIY exemption for electrical work, even on your own property.

Hack-It Electrical Solutions holds NSW Electrical Contractor Licence #230609C. We operate throughout Bellingen, Coffs Harbour, Sawtell, Nambucca Heads, Woolgoolga, Urunga, Dorrigo, Valla Beach, and Toormina.

Engaging in unlicensed electrical work can void your insurance, create significant safety hazards, and lead to fines. If someone offers to do the work cheaply without a licence, it’s not a saving—it’s a risk.

Answers to Your Common Queries

Is It Possible to Operate My Welder from a Standard Power Point?

Small stick welders (up to around 140A output) can be used with a standard 10A or 15A power point. any larger units require a dedicated circuit. A MIG welder with a capacity of 200A or more connected to a 10-amp GPO will trip the breaker immediately—or cause the wiring to overheat if the breaker is faulty. If you weld regularly, it’s essential to have a dedicated 32A circuit installed.

How Many Circuits Are Typically Required in a Workshop?

The number of circuits required depends on your tools, but a well-equipped workshop generally needs a minimum of 8 to 12 circuits. This includes dedicated circuits for each heavy tool (welder, compressor, plasma cutter), general power point circuits, dust extraction, lighting, as well as a couple of spares for future additions. We tailor the design based on your specific equipment list.

Is Three-Phase Power Necessary for a Home Workshop?

Not necessarily. Most home workshops function adequately on single-phase power with dedicated circuits. Three-phase power is only required if you are using commercial-grade equipment, such as large compressors (5HP+), three-phase welders, or CNC machines. Check out our complete guide on Do I Need Three-Phase Power on My Property? to determine if it suits your needs.

Can My Existing Switchboard Support a Workshop?

It’s possible. If your house switchboard is modern and has spare capacity, we can often connect a workshop sub-board to it. If it consists of an outdated ceramic fuse board or is fully loaded, an upgrade will be necessary before proceeding. We will evaluate this during the quoting process.

What Is the Typical Duration for a Workshop Electrical Fit-Out?

A basic single-phase setup can typically be completed within 1 to 2 days. A full fit-out encompassing multiple heavy circuits, three-phase power, and comprehensive lighting usually takes 3 to 5 days, depending on the complexity and cable run distances. We will provide a timeline along with your quote.

Ensure Your Workshop Is Properly Wired

If you are establishing a workshop on your property and want to ensure it is done correctly from the outset, reach out to us. We will visit your site, assess your space and equipment list, and develop a plan that meets your power requirements without compromising safety or quality.

Contact Hack-It Electrical Solutions at 0402 079 803 or reach out to us online to arrange a quote.

We are your local electricians in Bellingen, proudly serving the entire Mid North Coast from Nambucca Heads to Woolgoolga and up to Dorrigo.