Building an Electrical Cabinet

Tips and Tools

The Objective

DIY Electrical Cabinet Build

When you're diving into a DIY project to build your own electrical cabinet, whether it's for a 3D printer, CNC router, or any other CNC machine, it's crucial to invest the time and effort to create a clean setup. The main reason? Troubleshooting. If you miswire something or make a poor electrical connection, diagnosing the problem can become a nightmare. Is it your code? The machine configuration? Or the wiring? A clean and well-organized electrical cabinet eliminates one big variable, making it much easier to pinpoint and fix issues.

In my past YouTube videos, I'll admit, my wiring has often been subpar. With so many other tasks demanding attention in creating content, wiring frequently took a backseat. However, as I started working with more expensive electrical equipment, like my new MDPE10 extruder, I realized the stakes were much higher. A wiring mistake could fry this equipment, resulting in a serious monetary hit. My old electrical cabinet for the large format 3D printer was so cramped and messy that it was impossible to fit the new control components for the MDPE10. I had to start over, which made me realize that while I saved some time by not organizing initially, I lost a lot more time rebuilding the cabinet for the extruder upgrade.

So, I decided to invest the time and money to build a proper electrical cabinet. Now, I want to share these tips with you to help you avoid the same pitfalls and ensure your projects run smoothly.

Safety Warning: Mains wiring is very dangerous and can cause severe injury or death if not handled properly. Always unplug your equipment and ensure all power sources are disconnected before beginning any work on electrical components. Undersizing wires, connectors, or other electrical components can lead to excessive heat generation and potentially cause a fire. The advice and tips presented in this article are based on personal experience and are not CSA, UL, or CE certified. Always follow local electrical codes and consult a professional electrician if you are unsure about any aspect of your wiring project. Finally, there is some "do as I say and not as I have done" in this article.

5 Quick Tips

Before diving into the details of cabinet building, here are some quick tips for those in a hurry.

1. Label All Wires with Laminating Wire Wraps

Use a Brady M210 labeler for durable, professional wire labels that securely wrap around wires, unlike standard label makers that produce flag-like labels.

Laminated wire wraps for labeling wires in electrical cabinet

2. Color Code Wires and Terminals:

Color coordinated silicone wires and terminals for DIY electrical cabinet

Color coding your wires and terminals helps maintain organization and ensures safety. Below are the standard colors that I follow for my cabinets that use a mix of AC and DC voltages:

For easy-to-manage wiring, use silicone stranded wire. My favorite silicone stranded wire is flexible and handles well, making it ideal for a neat and efficient setup. You can find color-matched terminals by Dinkle, and here’s a quick nomenclature for buying terminal blocks for different amperages:

3. Use Wago Connectors for Quick Connections

Wago connectors are an excellent choice for quick and reliable electrical connections. They are low profile, allowing you to make connections without the bulk of traditional terminals. Additionally, Wago connectors eliminate the need for jumpering terminals to splice multiple wires together. For added convenience, use plastic Wago DIN mounts to secure them to DIN rails, keeping your setup organized and accessible.

Laminated wire wraps for labeling wires in electrical cabinet

4. Repurpose SSR DIN Rail Mounts with 3D Printing

Use SSR (Solid State Relay) DIN rail mounts in combination with 3D printing to easily mount components not traditionally designed for DIN rails. For example, you can 3D print a mounting bracket for a 3D printer controller board and bolt it to the SSR mount. This method provides a flexible and cost-effective way to securely mount various components within your electrical cabinet.

5. Use a Fiber Laser Cutting Service for Cutting Passthrough Plate

Opting for a fiber laser pass-through plate is much cleaner method to cutting out all the holes required for panel mount connectors.

Instead of drilling holes into the thin sheet metal plate provided with your enclosure, use a fiber laser cutting service like SendCutSend or OSHcut (no affiliation). These services can precisely cut out holes for panel mount connectors, including those with more complex shapes like four-corner mounts. Additionally, consider cutting some extra holes into your CAD modeling/drawing for future expansion, which can be easily plugged if not needed immediately. Here are some of my favorite panel mount connectors:

Planning

DIY Electrical Cabinet Build

Clearance

The first step is to identify all the mission-critical components needed to make the machine function, such as the power supply, motor drivers, microcontroller, and other essential parts. Next, locate their datasheets. These datasheets provide crucial technical information, including the exterior dimensions of the components and, more importantly, the separation or clearance needed from other components to prevent overheating. This buffer space is often overlooked, but it is essential to avoid overheating and potential damage to your components.

For example, the Meanwell LRS-350 is very popular power supply for building 3D printers and other CNC machines (datasheet here). However, this is a heat-sensitive component where a 10-15 cm clearance must be kept when the adjacent device is a heat source. In fact, the manufacturer supplies a curve that shows the max power output of the PSU drops with increasing ambient temperature. This leads to another important tip: Avoid placing heat-sensitive items near large heat producers. Heat-sensitive items also include microcontrollers, sensors, capacitors, and batteries. Heat producers include power supplies, motor drives, power resistors, relays, solenoids and voltage regulators.

Safety Devices

While you have the datasheets out, check the power requirements of each component.

Next, identify the necessary safety electrical components. Below is a list of common safety components found in nearly every electrical cabinet and a brief description of how to select the correct one:

Work in Progress: This article is currently being updated. Please check back soon for comprehensive information on building and organizing your electrical cabinet. Thank you for your patience!

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