Mastervolt DC Master 24/12 50-60A User Manual
Product: DC-DC converter
Manufacturer: Mastervolt
Address: Snijdersbergweg 93, 1105 AN Amsterdam, The Netherlands
Contact: Tel.: +31-20-3422100, Fax: +31-20-6971006, Email: info@mastervolt.com
Document Version: February 2015
1 General Information
1.1 Use of this manual
This manual is valid for the Mastervolt DC Master 24/12 50 model (Part number: 81400352). Reproduction or distribution without Mastervolt's written permission is prohibited. Keep this manual in a secure place.
1.2 Product Description and Application
The Mastervolt DC Master converts a 24V DC voltage to a 12V DC voltage. It is typically used with a 24V battery bank to power 12V equipment.
1.3 Use of Pictograms
Safety instructions and warnings are marked with the following pictograms:
- WARNING ⚠️: Refers to possible injury to the user or significant material damage if procedures are not followed carefully.
- CAUTION! ?: Indicates special data, restrictions, and rules to prevent damage.
- Procedure/Attention ➡️: Highlights a procedure, circumstance, or detail requiring extra attention.
1.4 Identification Label
The identification label is located on the rear side of the DC Master. It contains important technical information for service and parts. Do not remove this label. The label includes details such as Part Number (P/N: 81400352), Type (DC Master 24/12 50A), Input voltage (17-32V), Output voltage (13.6V 50A nominal, 60A Max), and Serial Number.
1.5 Liability
Mastervolt is not liable for consequential damage due to the use of the DC Master or for errors in the manual.
2 Important Safety Instructions
READ AND SAVE THESE INSTRUCTIONS
This chapter describes important safety and operating instructions for the DC Master in residential, recreational vehicle (RV), and marine applications.
2.1 General
Read all instructions and cautionary markings before use. To reduce the risk of electric shock, do not expose the unit to rain, snow, spray, moisture, or excessive pollution. To reduce fire risk, do not cover ventilation openings. Do not install in non-ventilated rooms. Use only recommended attachments/spare parts. Do not operate if damaged; seek qualified service. Disconnect from input and output before maintenance. Short-circuiting or reverse polarity will cause serious damage and void the warranty. Use appropriate fire extinguishers for electrical equipment. Marine installations in the US must comply with US Coast Guard Electrical Regulations.
2.2 Explosive Gases
WARNING ⚠️: RISK OF EXPLOSIVE GASES. Working near lead-acid batteries is dangerous as they generate explosive gases. Always read and follow this manual's instructions. To reduce explosion risk, follow battery manufacturer instructions and avoid areas with gas or dust explosion danger or where ignition-protected equipment is required.
2.3 Warning Regarding Life Support Applications
The DC Master is not intended for use in medical life support systems unless a specific written agreement with Mastervolt is in place, including additional reliability testing and manufacturer indemnification.
2.4 Guarantee Specifications
Mastervolt guarantees the unit meets applicable standards. Damage or failure to meet specifications due to non-compliance with manual instructions may invalidate the guarantee. The guarantee covers repair/replacement costs only; installation labor and shipping are not covered.
3 Installation
3.1 Before You Start
Ensure the battery voltage matches the DC Master's input voltage (24V for this model). Fuses must be installed in positive wires, placed last. Recommended fuses: Input fuse (50A), Output fuse (60A), Remote switch fuse (2A - T). Keep DC cable connections short (max 3m/10ft). Use colored cables (red for positive, black for negative). Recommended wire gauges: Input wires (24V): 8 AWG / 10 mm², Output wires (12V): 6 AWG / 16 mm², Remote switch (24V): 16 AWG / 1.5 mm².
3.2 Choosing a Location to Install
Install in a well-ventilated area protected from rain, vapor, moisture, and dust for optimal heat discharge. Mounting vertically with cables downward is advised. Do not install in areas with gas or dust explosion danger. Allow at least 10 cm (4 inches) of space around the unit. Avoid mounting directly above batteries due to corrosive fumes.
3.3 Contents of the Delivery
The delivery includes: DC Master 24/12 50-60A, mounting bracket, 4 screws, 4 screw covers, 4 mounting spacers, a 5-way terminal block with wire bridge, and this user's manual. Contact your supplier if any items are missing.
3.4 Installation Step-by-Step
1. Detach the mounting bracket from the DC Master using a flat-blade screwdriver. Mount the bracket to a solid surface using the provided screws and dowels. Insert the DC Master into the bracket until it clicks.
2. Connect wires as per Figure 2 (Wiring Diagram). Connect input wires first, then output wires. Do not install DC fuses yet.
a. For no remote switch function: Place the supplied wire bridge between the Enable contact (3) and Positive input (1).
b. For remote switch function: Remove the wire bridge and install the Remote switch fuse (8) and Remote switch (9).
3. Check all wiring. If correct, install the DC fuse(s). A spark may occur when the fuse is inserted due to internal capacitors; this is normal.
Wiring Diagram Description (Figure 2): The diagram shows connections for the DC Master. Key points include:
- 1: Positive input (27.2V)
- 2: Negative input (0V)
- 3: Enable (Active high)
- 4: Negative output (0V)
- 5: Positive output (13.6V)
- 6: Status LED
- 7: Input fuse
- 8: Remote switch fuse
- 9: Remote switch
- 10: Output fuse
- Connections are made to a 24V battery and a 13.6V load.
4 Operation
4.1 Switching On and Off
The DC Master is enabled by inserting the fuse. It does not have a main switch. Disconnect from the battery when not in use to prevent battery discharge, despite low no-load consumption.
4.2 Remote Switch Function
The DC Master can be operated remotely using an optional remote switch connected to the ENABLE input. The unit switches on when the ENABLE input is powered by the input voltage.
4.3 Status LED
| LED Indication | Meaning |
|---|---|
| Continuous green | DC Master is working OK |
| Other | Fault condition, refer to Chapter 5. |
4.4 Maintenance
No specific maintenance is required. Clean with a soft, dry cloth. Avoid liquids or corrosive substances. Regularly check wiring for loose connections or damage and correct immediately.
5 Trouble Shooting
If problems persist, contact a Mastervolt Service Centre. Have the article and serial number ready. Visit www.mastervolt.com/dealer-locator for details.
| Problem | Possible Cause | What to do? |
|---|---|---|
| Output voltage OK, Status LED yellow | High load | Reduce connected load. |
| Output voltage OK, Status LED yellow blinking @ 1Hz | Too high load | Reduce connected load; output power is limited by the DC Master. |
| Output voltage OK, Status LED yellow blinking @ 2Hz | Too high temperature | Reduce load and let the converter cool down. Output power is limited by the DC Master. |
| Converter switches on and off. | Too high load / Too high temperature / Voltage drop over DC cables / Loose connections | Reduce connected load. Reduce load and let the converter cool down. Check cable length and wire gauge. Check connections and replace if necessary. |
| No output voltage, Status LED is OFF | Input fuse blown | Check the cause of the blown input fuse(s) and replace the fuse(s). |
| No output voltage, Status LED flashing green | Enable contact is open | Connect Enable contact to the positive input (see sections 3.4 and 4.2). |
| No output voltage, Status LED is continuous red. | No input voltage or input voltage too low. | Check wiring, fuses, and battery. Check battery voltage, cable length, wire gauge. |
| No output voltage, Status LED is blinking red. | Input voltage too high / Converter shut down due to fault (high load, short circuit, high temp) / Converter shut down multiple times due to fault | Check battery voltage. Reduce load and let the converter cool down (auto-restart after 1 min). Reduce load and let the converter cool down (manual restart by switching DC input off/on). |
6 Technical Data
6.1 Specifications
| Model | 24/12 50A |
| Article no. | 81400352 |
| Function | Non-isolated 24V to 12V DC-DC converter |
| Nominal input voltage: | 27.2 V (18.0-32.0 V) |
| Max. input current | 30A |
| Nominal output voltage: | 13.6 V +/- 5% |
| Output current | 50 A continuous, 60 A peak during 2 minutes @ 30°C [86 °F] |
| Ripple | 2% of output voltage |
| Parallel fitting | Yes, up to 4 DC Masters of the same model |
| Efficiency at full load | >90% |
| No load consumption (on/off) | 15 / 5 mA |
| Temperature range | -25 to +80 °C [-13 to 176 °F]. Load must be reduced at temperatures between 35 and 80°C [86 and 176 °F]. |
| Cooling | Natural convection |
| Connections | 5-way terminal block for wires 1.5mm up to 16mm² [16 up to 6 AWG]. Stripping length: 14mm [0.55 inch]. Tightening torque: 1.7 – 1.8 Nm [15-16 InLbs] |
| Dimensions in mm (inch): | 283 x 125 x 74 mm [11.14 x 4.92 x 2.91 inch] |
| Weight in kg: | 1.8 kg [4.0 lbs] |
| Protection degree | IP 53 |
Specifications are subject to change without prior notice.
6.2 Dimensions
Dimensions Diagram Description: The diagram shows the physical dimensions of the DC Master in millimeters (and inches in brackets). The overall dimensions are approximately 283 mm (length) x 125 mm (width) x 74 mm (height). Specific measurements are provided for different views: Length (272mm), Width (126mm), Height (75mm), depth of mounting bracket area (75mm), width of mounting bracket area (84mm), height of mounting bracket area (193mm), and base dimensions (58mm x 33mm).
7 EC Declaration of Conformity
Manufacturer: Mastervolt
Address: Snijdersbergweg 93, 1105 AN Amsterdam, The Netherlands
Mastervolt declares that the product:
- Product: DC-DC-converter
- Model: DC Master 24/12 50-60A
- Article no.: 81400352
is in conformity with the provisions of the following EC directives:
- 2004/108/EC (EMC directive), harmonized standard applied: EN 60945:2002 (Maritime navigation and radio communication equipment and systems).
- 2011/65/EU (RoHS directive).
Declaration made in Amsterdam, 11 February 2015 by H.A. Poppelier, Global R&D Leader.
