Dedicated Circuits for Heavy Tools in Workshops

If you own a shed on a rural property and are contemplating its transformation into a fully functional workshop, prioritising the electrical setup is essential.
Employing tools such as a MIG welder, air compressor, and table saw on the same circuit as your residence can result in serious complications, including frequent tripped breakers, flickering lights, and potentially dangerous overload situations.

This in-depth guide investigates the critical elements involved in establishing a properly wired workshop in the rural areas of the Mid North Coast. Key topics include dedicated circuits, sub-boards, and the benefits of utilising three-phase power for larger machinery. Should your requirements be limited to basic power needs for your shed—like lighting and a few outlets—please consult our guide on Shed Wiring on Acreage for a more suitable introduction. This article specifically addresses workshops that require a substantial power supply.

Recognise the Significance of Dedicated Circuits for Your Workshop

Most residential properties feature multiple power points connected to shared circuits, which works well for low-power devices like kettles and televisions. Issues arise when trying to run a 32-amp MIG welder alongside an air compressor at the same time. This scenario can lead to severe electrical complications.

Here’s what can happen when you connect heavy machinery to household 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 can react.
• Voltage drops — Extended cable runs from the main board to the shed can create voltage sag. This results in your tools operating at higher temperatures, reduced speeds, and deteriorating more quickly over time.
• Power interruptions in the house — Your partner might face a power outage in the kitchen because you turned on the compressor, leading to unnecessary disagreements.
• Increased fire hazards — Overloaded wiring within walls and cable runs is a primary contributor to electrical fires in rural areas.

Implementing dedicated circuits effectively mitigates these problems. Each heavy tool is assigned its own circuit, appropriately sized for its power needs, along with its own breaker protection. This ensures that nothing is shared, and nothing is overloaded.

Evaluate the Power Consumption of Common Workshop Machinery

Before your electrician can create an effective circuit layout, you must grasp the power requirements of your equipment. Here’s a detailed overview of typical power consumption for common workshop tools:

• MIG welder — Requires between 15A and 32A depending on the model. Larger 240V welders typically operate at the higher end. Three-phase units have distinct requirements (more on that later).
• Air compressor — Draws approximately 10A to 15A. The startup surge can be substantial—compressor motors often pull 3 to 4 times their running current for a few seconds upon activation.
• Table saw — Generally consumes 10A to 15A for a quality cabinet saw. More economical contractor saws may require less power, but you should avoid budget options.
• Lathe (wood or metal) — Similar to table saws, these usually require between 10A and 15A, with metal lathes often at the higher end.
• Dust extractor — Approximately 10A for a single-phase unit. It needs to operate continuously while using other tools, thus it should have its own circuit.
• Plasma cutter — Draws between 20A and 30A, akin to a welder, and also necessitates a dedicated circuit.

When you total the power consumption, it becomes clear that a single 20-amp circuit from the house will be insufficient. A fully equipped workshop can easily demand 80 to 100+ amps across all circuits when operating at full capacity, underscoring the need for meticulous planning.

Select the Appropriate Circuit Breaker Size and RCD Protection for Safety

Every circuit in your workshop must feature a breaker that corresponds to the cable size and anticipated load. Your electrician will determine 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 — Essential for welders, plasma cutters, and other heavy single-phase machinery.
• Three-phase breakers — Sized according to specific equipment requirements (details below).

RCD protection is vital. According to AS/NZS 3000 (the Australian Wiring Rules), all power and lighting circuits must include RCD (safety switch) protection. This requirement is not optional; it is a legal mandate aimed at safeguarding against the high-risk nature of workshop environments.
Concrete floors, metal tools, dust, and moisture heighten the likelihood of earth faults. RCDs instantly cut power if a current leak to earth occurs, which can mean the difference between a minor shock and a serious injury.

Typically, your electrician will use 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 others, enhancing safety and reliability.

Install a Dedicated Sub-Board for Your Workshop's Electrical Needs

Instead of running multiple individual cables back to the main switchboard, establishing a dedicated sub-board in your workshop is a more efficient strategy. Here are the advantages:

• Shorter cable runs — A single 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 arrangement reduces voltage drop and lowers cable costs.
• Simplified fault diagnosis — Each circuit is clearly labelled and easily accessible in the workshop. If a breaker trips, you won’t need to return to the house to reset it, saving time and effort.
• Future expansion — A properly sized sub-board accommodates additional circuits later on, making it straightforward to incorporate new tools as your workshop evolves.
• Isolation capability — You can switch off all workshop power from a single main switch without disrupting the house's electricity, enhancing safety during maintenance.

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 support the increased load.

A typical workshop sub-board configuration 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 enhancements, ensuring optimal performance and safety.

Ensure Your Workshop Is Well-Lit for Safety and Efficiency

Sufficient lighting is crucial for safety in your workshop. You must be able to see your work clearly, especially when handling sharp blades and hot materials. Here are some key lighting considerations:

• High-lumen LED battens — LED panels or battens provide bright, consistent lighting throughout the space. Aim for a minimum of 500 lux at bench height to ensure visibility.
• Dust-proof fittings — Regular lights can be obstructed by sawdust and metal shavings. Opt for IP-rated fittings that resist dust and moisture for durability and safety.
• Task lighting at workstations — While overhead lighting illuminates the general area, focused lighting at the workbench, lathe, and drill press is essential for precision work and safety.
• Separate lighting circuit — Lighting should operate on its own circuit, ensuring that you still have illumination if a power circuit trips. Being left in darkness next to a running table saw poses a significant safety risk.

We have considerable experience with lighting layouts in commercial environments. Our team can assist you in crafting a workshop lighting plan that significantly enhances your working conditions and safety.

Plan for Efficient Ventilation and Dust Extraction Circuits

When performing tasks such as woodworking or welding, ensuring adequate ventilation is just as crucial as having sufficient power. Dust extraction systems and exhaust fans require their own dedicated circuits for the following reasons:

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

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 may require a 20A circuit based on motor specifications, ensuring efficiency and effectiveness in maintaining air quality.

Utilise Three-Phase Power for Enhanced Efficiency with Heavy Equipment

When engaging in intensive metalwork or operating large compressors (5HP+) or commercial-grade woodworking machinery, single-phase power may reach its limits. Three-phase power provides several advantages:

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

Accessing three-phase power in rural areas on the Mid North Coast depends on availability at the street level. Some properties may already have a three-phase supply, while others might need a phase converter or a new connection from Essential Energy.
For further information, please consult our guide on Do I Need Three-Phase Power on My Property?

If three-phase power is accessible, your workshop will require the installation of a three-phase switchboard with appropriately rated breakers and an efficient earthing system to ensure safety and reliability.

Implement Surge Protection to Safeguard Your Equipment

Tools equipped with electronic controls, variable frequency drives (VFDs), digital displays, and inverter welders are vulnerable to voltage spikes. Notably, your workshop generates surges each time a large motor starts or stops. Coupled with the voltage instabilities often found in rural power lines, your valuable 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 a CNC controller, thereby preserving your investment.

If your property frequently experiences storms (which is common on the Mid North Coast), we recommend adding surge protection at the main switchboard to defend against lightning-induced surges that could damage your equipment.

For properties that rely on a generator for backup power, incorporating a generator changeover switch ensures seamless transitions between mains power and generator supply without risking back-feeding or harming connected devices, providing peace of mind during power outages.

Consider Additional Features for Your Workshop Wiring

Here are several more components 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, ensuring durability. Consider double power points at every bench and outlets at key machinery locations to enhance accessibility.
• 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 alongside the electrical setup. Running cables during the initial fit-out is significantly easier than after the walls are finished, preventing future complications.
• External lighting — Include floodlights outside the workshop to facilitate access during early mornings and late evenings, especially in rural areas lacking street lighting, enhancing safety.
• 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, ensuring efficient operation of all devices.

Accurately Estimate the Cost of Your Workshop Electrical Installation

Cost estimates will vary based on the 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, providing foundational electrical support.
• Complete dedicated sub-board (8–12 circuits, multiple heavy tool circuits, dust extraction, comprehensive lighting design) — Starting from £10,000, ensuring ample capacity for serious workshop needs.
• Three-phase workshop build (three-phase supply, dedicated board, heavy equipment circuits, complete fit-out) — Starting from £15,000+, accommodating extensive power requirements.

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, ensuring you know precisely what to expect.

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

This is a crucial 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, to ensure safety and compliance.

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, ensuring quality service.

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 that can have serious repercussions.

Find Answers to Your Common Questions Regarding Workshop Electrical Needs

Can I Operate My Welder from a Standard Power Point?

Small stick welders (up to around 140A output) can function 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 potentially cause the wiring to overheat if the breaker is faulty. If you weld regularly, it’s crucial to have a dedicated 32A circuit installed to ensure safe operation.

How Many Circuits Are Typically Necessary in a Workshop?

The number of circuits needed depends on your tools, but a well-equipped workshop typically requires 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, ensuring you have everything you need.

Is Three-Phase Power Required for a Home Workshop?

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

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 assess this during the quoting process to ensure everything aligns with current standards.

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 that includes 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, ensuring you know what to expect.

Ensure Your Workshop Is Properly Wired for Safety and Efficiency

If you are establishing a workshop on your property and wish to guarantee it is done correctly from the outset, contact 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, ensuring a successful workshop setup.

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

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