ENGINEERING / MANUFACTURING · BUYER GUIDE

12V vs 24V LED Signs: What Changes for Wiring and Power Supplies?

For constant-voltage LED sign systems, 12V and 24V refer to the required DC supply voltage of the selected components. Choose the system as a compatible set. A 24V power supply is not a way to improve a sign built with 12V modules.

Compare current at the same load

Using the electrical relationship P = V × I, an illustrative 120W load draws 10A at 12V or 5A at 24V. This comparison assumes the same electrical load; it does not establish the brightness or efficiency of two different LED products. Their actual specifications still need to be compared.

Illustrative equal load	12V system	24V system
Electrical power	120W	120W
Calculated DC current	10A	5A
Required LED input	Compatible with 12V	Compatible with 24V

Review the cable route with the designer

At the same cable resistance, a lower current produces less voltage drop according to ΔV = I × R. That can influence the choice for a distributed sign, but it does not justify an unlimited cable length. The designer must consider the actual cable, branch arrangement, allowable module voltage and installation requirements.

Keep the full component chain compatible

Confirm module input, power-supply output, controller rating and any connectors or distribution components. Constant-current products need a different selection method. Record the specified models on the drawing so replacements are selected against the actual assembly rather than a general description such as “LED driver.”

Select the supply for its real installation

Nominal wattage is only part of selection. MEAN WELL’s installation guidance directs users to the model specification for mounting and temperature-related derating. Apply the instructions for the actual supplied model and have a qualified designer settle the installation. Do not adopt one universal spare-capacity percentage for every product.

Reference: MEAN WELL: LED power-supply installation manual.