- Stock: 38
- Model: PSU-12v20a250w-fan
Model:
12V 5A 60W
12V 10A 120W
12V 15A 180W
12V 20A 250W Fan
12V 33A 400W
12V 40A - 500W
24V 10A 240W
24V 15A 360W
24V 20A 500W
24V 25A 600W
24V 33A 800W
36V 10A 360W
48V 10A 500W
A compact 12 V, 20 A, 250 W AC/DC switching power supply with an integrated fan for active cooling. It is intended for 12 V 3D printers, CNC systems, LED lighting, motors and electronic equipment requiring more current than a passively cooled supply.
It can power a small 12 V 3D printer with a heated bed when the combined consumption of the bed, hotend, controller, motors, fans and accessories remains within the 20 A nominal limit with headroom for load peaks.
Technical specifications
| Feature | Value |
|---|---|
| Type | Single-output AC/DC switching power supply |
| Selectable input | 100-120 V AC, 60 Hz / 200-240 V AC, 50 Hz |
| Nominal output | 12 V DC |
| Maximum nominal current | 20 A |
| Power | 250 W |
| Cooling | Integrated fan and ventilated metal enclosure |
| Output adjustment | Fine adjustment through V ADJ |
| Connections | Terminals for L, N, earth, V- and V+ |
| Contents | 1 power supply |
Integrated protection
- Short-circuit protection.
- Overload protection.
- Overvoltage protection.
- Overtemperature protection.
- EMI filtering to reduce electromagnetic interference.
- Full-load operation test.
Load sizing
At 12 V, approximate current can be calculated with current = power / 12. Useful examples for adding loads include:
| Total load | Approximate current at 12 V |
|---|---|
| 60 W | 5 A |
| 120 W | 10 A |
| 180 W | 15 A |
| 216 W | 18 A |
A load does not have to draw 20 A: the supply delivers only the current requested by the equipment, up to its nominal limit. For lower loads that do not require a fan, see the compact 12 V, 10 A, 120 W power supply.
Using a heated bed
Before installation in a printer, add the nominal bed and hotend loads to the controller, motors, fans and accessories. The heated bed is normally the largest load. If the controller cannot switch its current directly, a 12/24 V external heated-bed MOSFET module can be used while still sizing the supply, wires, connectors and fuses correctly.
The MOSFET does not increase available power; it only switches the load through a separate stage. Keep thermal protection enabled and ensure that a control fault cannot leave a heater powered without supervision.
Electrical connection
- Select the input: set the selector to 220/230 V before connecting to a 230 V, 50 Hz supply.
- Connect mains: live to
L, neutral toNand protective earth to the earth terminal. Bond the metal enclosure correctly to protective earth. - Connect the load: positive to
V+and negative toV-, observing polarity and distributing current through suitable conductors and terminals. - Measure before use: check output voltage and polarity with a multimeter before connecting a controller or heater.
V ADJ is for fine correction around 12 V and must not be used to power devices intended for a different nominal voltage. A 12 V supply is not compatible with heaters, fans or controllers designed exclusively for 24 V.
Mounting and ventilation
- Keep the fan intake, exhaust and every enclosure slot unobstructed.
- Do not install near water, conductive dust, swarf, flammable material or heat sources.
- The transparent terminal cover is supplementary protection and does not replace the final equipment enclosure.
- For short internal machine runs, 2.5 mm² is a suitable starting point for output circuits up to 20 A; check length, voltage drop, temperature, bundling and local requirements.
- Do not open the enclosure or handle internal parts. Disconnect mains and verify the absence of voltage before working on terminals.
An IEC inlet with switch and a Schuko to IEC C13 lead can provide a detachable input when combined with the correct protection and wiring.
Firmware
There is no power-supply-specific Marlin, Klipper or RepRapFirmware setting. Configure and retain hotend and heated-bed thermal protection, and run PID autotune if the supply change alters heater response. Physically verify the nominal voltage of every component before applying power.
EQUIPMENT START UP:
- Check that the mains voltage matches the input selected for the source (110/220v)
- Connect the power supply to the mains to check the output voltage (12/24v)
- The output voltage is adjustable, if it differs from the one you want for your application you can turn the regulator, preferably with the equipment off. Never use a metal screwdriver with the equipment on to make this adjustment.
- (Depending on the model) This power supply has a regulated fan, it will turn when it has load, check periodically and in the first use that the fan is activated correctly.
SAFETY INSTRUCTIONS COMPACT POWER SUPPLY:
- Dimension the installation correctly, with an appropriate safety factor.
- Never block or hinder the fan's air output.
- Before connecting the equipment to the power supply, check that the available mains voltage corresponds to the voltage value of the equipment.
- Connect the mains cable of the equipment to a grounded power outlet.
- Do not place the equipment on wet or damp surfaces.
- Do not expose the equipment to direct sunlight or extreme temperatures.
- Do not expose the equipment to moisture.
- Do not exceed the maximum input voltage allowed.
- Comply with the warning and information labels on the equipment.
- Wear dry clothes and rubber shoes to ensure insulation.
- Do not insert metal objects into the equipment through the ventilation slots.
- Do not place containers full of liquids on the equipment (danger of short circuit in case of shock).
- Do not use the equipment near strong magnetic fields (motors, transformers, etc.).
- Do not expose the equipment to strong shocks or vibrations.
- Allow the unit to stabilize at room temperature before taking measurements (important for accurate measurement).
- Do not modify the equipment in any way.
- The equipment must be opened for service or repair by qualified personnel. It is recommended that repair work be carried out in the presence of a second person trained to perform first aid if necessary.
- Keep the power source away from children.
- Before cleaning the box, pull out the plug from the socket. Clean only with mild household cleaner. Make sure that no water gets inside the equipment to avoid possible short circuits and damage to the equipment.