Power Supply - Fuse & Relay Holder

This section covers the design, fabrication, and wiring of the custom 3D-printed fuse and relay holder used in the power supply build. Individual files used during development, as well as the final model, are included below. If you require alternate file formats, feel free to reach out.

Design Overview

The holder was designed to securely mount sixteen automotive-style relays and two blade fuses in a compact, serviceable layout. It includes slots for crimp terminals and mounting holes for integration into the enclosure. The layout prioritizes accessibility and modularity, allowing easy replacement of components without disturbing adjacent wiring.

Materials & Methods

• Material: PLA filament
• Printer: Creality Ender 3 Max Neo
• Layer Height: 0.25mm
• Infill: 75% grid pattern for strength
• Supports: Disabled

Wiring the Holder

Wiring the holder is straightforward. Refer to the wiring layout section for pin assignments and routing. Below are images showing the wiring process and terminal placement:

Terminals Used

The following terminals were used for connecting relays and fuses:

• Relay Pins 30 & 87: 6.3mm Terminals
• Relay Pins 85, 86, 87a: 4.8mm Terminals
• Flasher Relay Pins (both): 6.3mm Terminals
• Fuse Terminals (both): Fuse Contact

Reference Documents

• Fuse & Relay Holder (Final Model) – STL
• Holder Assembly – STEP
• Dev Models – ZIP
• Power Supply Holder Layout – PDF