Power Wiring Instructions
- All wiring operations must be performed with the power off
- Carefully check the polarity before wiring; reverse connection may damage the device
Host Computer Power Supply
The host computer (such as Raspberry Pi, FLY-π, etc.) cannot use the 5V power provided by the motherboard. The 5V output current of the motherboard is limited and cannot meet the power requirements of the host computer. Forced use may lead to:
- Insufficient power supply to the host computer, system instability, or frequent reboots
- Overload of the motherboard's 5V line, burning the motherboard or host computer
Recommended Power Supply Methods
| Power Supply Method | Description | Recommendation Level |
|---|---|---|
| Independent 5V Power Adapter | Use an independent 5V/3A or higher power adapter to directly power the host computer | ⭐ Most Recommended |
| Fan Port 24V to 5V Conversion | Use the 24V output from the motherboard's fan port and convert it to 5V via a DC-DC buck module | Optional Solution |
Independent Power Adapter Power Supply
Directly use a compliant 5V power adapter via USB or GPIO to power the host computer. This is the most stable and reliable method.
Requirements:
- Output Voltage: 5V
- Output Current: ≥ 3A (Recommended)
- Interface matching the host computer's power input (USB-C / Micro USB / GPIO)
Fan Port 24V to 5V Power Supply
If an independent 5V power supply is unavailable, you can use the 24V output from the motherboard's fan port and convert it to 5V via a DC-DC buck module to power the host computer.
Required Materials:
- DC-DC Buck Module (24V to 5V, output current ≥ 3A)
Wiring Method:
- Connect the module's input terminals (VIN+/VIN-) to the 24V and GND of the motherboard's fan port
- Adjust or confirm the module's output is 5V
- Connect the module's output terminals (VOUT+/VOUT-) to the host computer's power pins
- Before use, confirm the buck module output voltage is 5V (normal range 4.75V-5.25V) using a multimeter
- Ensure the buck module's rated output current is ≥ 3A
- Pay attention to polarity during wiring; reversing connections will burn the host computer
- Measurement Method: Set the multimeter to DC voltage mode (20V range), red probe to VOUT+, black probe to VOUT-
Power Safety Check
Before turning on the power, be sure to perform the following safety checks to ensure safe device operation and prevent electric shock and device damage.
Leakage Detection
Use the high resistance range (20MΩ or 200MΩ range) of a digital multimeter for leakage detection.
Detection Process
Step One: Overall Device Leakage Detection
- Power Off: Ensure the device is completely powered off, unplug all power cords
- Measurement Points:
- Touch one multimeter probe to the device's metal casing (frame, metal frame)
- Touch the other probe successively to the Live (L) and Neutral (N) prongs of the power plug
- Result Judgement:
- Normal: Resistance > 10MΩ (shows "OL" or exceeds range)
- Note: Resistance between 2MΩ ~ 10MΩ indicates degraded insulation; investigation is recommended
- Abnormal: Resistance < 2MΩ, leakage risk exists, do not power on
Step Two: Key Component Leakage Detection
| Component | Measurement Points | Normal Value | Abnormal Value |
|---|---|---|---|
| Heatbed | Heated metal plate surface ↔ Power terminal | > 10MΩ | < 2MΩ |
| Stepper Motor | Motor housing ↔ Winding pins (A+/A-/B+/B-) | > 10MΩ | < 5MΩ |
| Hotend | Metal part ↔ Heater cartridge/Thermistor wiring | > 10MΩ | < 5MΩ |
| Fan | Metal housing ↔ Power wires | > 10MΩ | < 5MΩ |
Step Three: Troubleshooting Abnormality
If leakage is detected, troubleshoot in the following order:
- Check the power cord insulation for damage or aging
- Check if internal wiring is touching the metal casing
- Check the circuit board for dirt, dust, or moisture
- Check if the heating element/motor winding is shorted/broken down
- Check if components are installed with insulating washers (especially between the heatbed and metal frame)
- Detection Frequency: Must be checked before the first use of a new device, then every 3-6 months
- Environmental Factors: Increase detection frequency in humid environments
- Emergency Handling: Immediately cut power and inspect if leakage is found; do not force use
- Measurement Note: Do not touch the metal part of the probe during measurement to avoid affecting results
- Multimeter Limitation: Standard multimeters use low voltage (usually 3-9V) for measurement and may not detect insulation issues under high voltage. If resistance is in the borderline range (2-10MΩ), pay close attention
Ground Wire Check
The ground wire is an important safety measure connecting the device's metal casing to the earth. It conducts leakage current to the ground, protecting personal safety.
Check Steps:
-
Ground Continuity Test:
- Set the multimeter to Continuity (Buzzer) mode
- Touch one probe to the device's ground terminal (usually marked "GND" or ground symbol ⏚)
- Touch the other probe to the ground prong of the power plug (the longest prong on a three-prong plug)
- Normal Result: Should hear a beep, resistance close to 0Ω, indicating a good ground path
- Abnormal Result: No beep or excessive resistance, indicating poor grounding
-
Ground Wire Visual Inspection:
- Check if the ground wire is securely connected, free from looseness or corrosion
- Check the ground wire for damage or breaks
- Confirm the socket's ground terminal is correctly grounded (a socket tester can be used)
Importance of the Ground Wire:
- Prevents electric shock, protecting operator safety
- Reduces electromagnetic interference, improving device stability
- Prevents static electricity buildup, protecting sensitive electronic components
- The ground wire must not be omitted; ensure reliable grounding
- If poor grounding is found, stop use immediately and repair
- Older buildings may have incomplete grounding systems; it is recommended to have a professional electrician inspect them