3D printer voltage switch: 115 V or 230 V?

Set the voltage switch to 115 V in the US. That position is for 100 to 120 V mains, which covers a standard 120 V outlet. The 230 V position is for 200 to 240 V countries, and it is the factory setting in Creality’s manuals, so check the switch before plugging in a new printer.

Should a 3D printer’s voltage switch be set to 115 V or 230 V?

Set it to 115 V on US power. Creality’s manuals say to select 115 V when the mains is between 100 and 120 V, and 230 V when it is between 200 and 240 V. The same manuals list 230 V as the default, so a new printer usually needs switching before its first power-on.

Mean Well’s LRS-350-24, a 24 V, 350 W supply with the same kind of switch, rates each position this way:

Switch position	Mains it accepts	Typical input current at full load
115 V	90 to 132 V AC	6.8 A at 115 V
230 V	180 to 264 V AC	3.4 A at 230 V

Why 115 V when US outlets are 120 V?

115 V names the low range, not an exact voltage. Mean Well’s 115 V band runs from 90 to 132 V AC, and a 120 V outlet sits well inside it. The 230 V band starts at 180 V, far above anything a US outlet supplies.

Where is the voltage switch on a 3D printer?

It’s on the power supply itself, not on the screen or the on/off rocker. Look for a small slide switch marked 115V and 230V. On the Ender-3 V3 Plus the manual shows it at the wiring step, just before you connect the power cable. The K1 SE manual says to move it with a straight (flat-blade) screwdriver, which suggests a recessed slider.

How do I check which position the switch is in?

1. Turn the printer off and pull the plug from the wall.
2. Find the slide switch on the power supply and read the marking beside the slider.
3. If it reads 230V and you are on US power, push it to 115V with a flat screwdriver until it clicks into place.
4. Plug in and switch on.

Move only that switch. The Ender-3 V3 Plus manual says not to remove any cover, and that there are no user-serviceable parts inside.

What happens if a 3D printer’s voltage switch is set wrong?

On 230 V mains with the switch at 115 V, the supply’s input stage gets about twice its design voltage and is likely destroyed, often blowing its fuse. On 120 V mains with the switch at 230 V, the supply runs below its rated input range. The printer may not start, or it resets when the heaters draw power.

Set to 115 V on 230 V mains

In the 115 V position the switch turns the input rectifier into a voltage doubler. That turns 115 V AC into the 300 to 320 V DC the supply’s switching stage expects, as Sam Goldwasser’s switchmode repair notes explain. Feed it 230 V and it doubles that instead:

DC voltage ≈ AC voltage × 1.414 (× 2 when the doubler is on)

Designed:           115 V × 1.414 × 2 = 325 V DC
Switch at 115 V,
plugged into 230 V: 230 V × 1.414 × 2 = 650 V DC

The filter capacitors and the switching transistor see double their design voltage. A shorted switching transistor typically blows the supply’s internal fuse right away. Creality’s Ender-3 V2 Neo manual warns that picking the wrong mode can burn out the power supply.

In the US this mistake is uncommon, because a printer’s 120 V plug, a NEMA 5-15, won’t fit a 240 V NEMA 6 outlet. The National Electrical Manufacturers Association (NEMA) arranges the blades differently on purpose. It happens when a printer set for the US is taken to a 230 V country.

Set to 230 V on 120 V mains

This is the common US mistake, because 230 V is the factory setting. The doubler stays off, so 120 V AC becomes only about 170 V DC, roughly half of what the supply expects. 120 V is also well below the 180 V bottom of the 230 V band. A switching supply can run below its rated input, but its regulation gets poor and the switching transistor carries much more current. Expect one of these:

• The printer won’t power on.
• It boots, then resets when the heated bed and hotend start heating, the moment the supply has to deliver its full output.

Unplug it, set the switch to 115 V, and try again. Sustained running in the wrong position stresses the supply, so test it under load: heat the bed and the nozzle together and watch for resets.

What to check if the printer won’t power on after a wrong setting

1. Unplug it and set the switch to the right position for your mains.
2. Check the outlet with a lamp or phone charger, so you know power is reaching the plug.
3. Try it again. If the screen and fans come on, run a heat-up of the bed and nozzle before you print.
4. No screen, no fans, nothing: the supply is probably dead, and in the 115-on-230 case the internal fuse has likely blown too. Replace the supply rather than the fuse.

Don’t open the supply. Its filter capacitors can hold a charge after it is unplugged. Mean Well’s installation manual warns against removing the case and says any failure should be examined by a qualified technician. A replacement must match the output voltage on the old supply’s label, at the same or higher wattage. The power supply calculator sizes it from your bed, hotend and other loads. Swapping a supply means disconnecting mains terminals, so have a qualified technician do it if you’re unsure.

Which 3D printers have a voltage switch?

Printers built around a manual-select supply have one. Their spec sheet shows two separate input ranges, such as “100-120V~, 200-240V~”. Printers with a single range, such as “100-240 VAC”, have universal input: they adjust automatically and have no switch to set.

Printer or supply	Input voltage as listed	Switch	Factory setting
Creality Ender-3 Pro	230 V or 115 V, selectable	Yes	not stated
Creality Ender-3 V2 Neo	100 to 120 V~, 200 to 240 V~	Yes	230 V
Creality Ender-3 V3 Plus	100 to 120 V~, 200 to 240 V~	Yes	230 V
Creality K1 SE	100 to 120 V~ / 200 to 240 V~	Yes	230 V
Mean Well LRS-350-24 supply	90 to 132 / 180 to 264 V AC by switch	Yes	n/a
Bambu Lab A1 mini	100 to 240 V AC	No	n/a
Bambu Lab X1 Carbon	100 to 240 V AC	No	n/a

If your printer’s manual or rear label shows one continuous range, there is nothing to set. Plug it into a grounded 120 V outlet. The circuit capacity calculator checks whether that outlet’s breaker can carry it alongside everything else.