MFJ-4115 Switching Power Supply User Manual

1. Introduction

The MFJ-4115 is a compact switching power supply designed to provide stable 13.8 VDC output with a continuous current of 15 Amps (17 Amps surge). It features over-voltage and over-current protection systems, a quiet fan, and super regulation. This manual provides essential information for the safe and efficient operation of your MFJ-4115 power supply.

Safety Information

• Always ensure proper ventilation around the unit. Do not block air vents.
• Do not expose the unit to moisture or extreme temperatures.
• Disconnect power before making any connections or performing maintenance.
• Ensure all connections are secure and correct polarity is observed.

2. Product Features

• Output Voltage: 13.8 VDC
• Output Current: 15 Amps continuous, 17 Amps surge
• Input Voltage: AC 90 to 130 Volts
• Protection Systems: Over-voltage and over-current protection
• Indicators: Load fault indicator
• Additional Features: Automatic shut-down, quiet fan, super regulation
• Compact Dimensions: Approximately 3.75 inches (W) x 2.25 inches (H) x 7.75 inches (D)
• Weight: Approximately 5.89 pounds
• Connections: One set of 5-way binding post connections

3. Setup

Follow these steps to set up your MFJ-4115 Switching Power Supply:

1. Unpack and Inspect: Carefully remove the power supply from its packaging. Inspect the unit for any visible damage.
2. Placement: Place the power supply on a stable, flat surface that allows for adequate ventilation. Ensure the fan vents are not obstructed.
3. Connect Device: Connect your device (e.g., radio equipment) to the 5-way binding post connections on the front of the power supply. Ensure correct polarity: the red terminal is positive (+), and the black terminal is negative (-). Tighten the connections securely.
4. Connect AC Power: Connect the provided AC power cord to the AC input receptacle on the rear of the power supply. Then, plug the other end of the AC power cord into a standard AC wall outlet (90-130V AC).

Figure 1: Front view showing the 5-way binding posts for device connection and the included power cord.

Figure 2: Rear view illustrating the AC power input, power switch, and cooling fan for ventilation.

4. Operating Instructions

Once the power supply is properly set up and connected:

1. Power On: Locate the power switch on the rear of the unit (refer to Figure 2) and switch it to the 'ON' position.
2. Monitor Operation: The power supply will now provide 13.8 VDC to your connected device. Observe the load fault indicator. If it illuminates or the unit automatically shuts down, refer to the Troubleshooting section.
3. Power Off: To turn off the power supply, switch the power switch to the 'OFF' position. For extended periods of non-use, it is recommended to unplug the AC power cord from the wall outlet.

5. Maintenance

Proper maintenance ensures the longevity and reliable operation of your power supply:

• Cleaning: Keep the unit clean and free from dust. Use a soft, dry cloth for cleaning. Do not use liquid cleaners or solvents.
• Ventilation: Regularly check that the fan vents are clear of obstructions to ensure proper airflow and cooling.
• Fan Noise: The internal cooling fan may produce some noise, especially upon startup or in colder environments. This is often normal and may subside after a short period of operation. If excessive or persistent noise occurs, ensure proper ventilation.

6. Troubleshooting

If you encounter issues with your MFJ-4115 power supply, refer to the following common problems and solutions:

• Unit Does Not Power On:
  • Check that the AC power cord is securely plugged into both the power supply and the wall outlet.
  • Ensure the power switch on the rear of the unit is in the 'ON' position.
  • Verify the wall outlet is supplying power.
• Load Fault Indicator Active / Automatic Shut-down:
  • This indicates an over-current or over-voltage condition. Immediately disconnect the load from the power supply.
  • Verify that the connected device's current draw does not exceed the power supply's continuous rating of 15 Amps or surge rating of 17 Amps.
  • Check for any short circuits in the connected device or its wiring.
  • If the issue persists with a known good load within specifications, the power supply may require service.
• Noisy Fan:
  • A slight fan noise, especially at startup or in cold conditions, is normal. It should quiet down after a short operating period.
  • Ensure the unit has adequate ventilation and the fan vents are not blocked.
  • If the noise is excessive or persistent, and not related to startup or cold, contact customer support.

7. Specifications

8. Warranty and Support

For warranty information, technical assistance, or service inquiries regarding your MFJ-4115 Switching Power Supply, please contact MFJ customer service directly. Refer to the official MFJ website or the product packaging for the most current contact details and warranty terms.