XLG 12V vs 24V LED Power Supplies: Which Voltage for Your Sign?

The non-negotiable voltage match

A nominal 24V supply can damage a 12V module, while a 12V supply will not operate a 24V strip as designed. “XLG 200W” is incomplete information: you must select and verify the output variant. Glowfy currently shows 12V and 24V options on its 100W, 150W and 200W XLG product pages; the 75W and 320W listings reviewed are 12V.

Check the exact selected variant in the basket and on the delivered output label. Some professional LED drivers have distinct constant-voltage and constant-current operating regions or adjustable outputs. Follow the particular datasheet and never rely only on the series name.

Why voltage changes the cable calculation

For a 120W load, nominal current is 120 ÷ 12 = 10A at 12V, versus 120 ÷ 24 = 5A at 24V. Lower current can reduce voltage drop and cable losses in a comparable run, but voltage drop still depends on cable resistance, length and branch topology. A 24V system does not make unlimited strip runs possible.

The LED product, not convenience, sets the system voltage. Never connect a 12V and a 24V load directly to one fixed-voltage output. If both are present in a project, design separate appropriately rated circuits or a manufacturer-approved conversion arrangement.

Example: 12V channel-letter modules

Suppose a sign uses 90 GL K8 PRO modules at 1.2W each. Total nominal load is 108W and current is 9A at 12V. A 150W 12V XLG could be shortlisted, subject to the exact variant’s load rating and temperature derating. The 150W 24V version is not interchangeable, despite having the same power number.

Lay out modules in permitted branches rather than putting 90 units on an arbitrarily long chain. Check the farthest letter under full load. If a 12V branch is long, the solution may involve an additional correctly sized feed or a separate circuit, not simply a higher-wattage supply.

Example: 24V strip in a light box

Glowfy SW24-15 is listed at 24V and 15W per metre. A single 5m reel has a nominal load of 75W and current of 3.125A. Two such reels have 150W total and 6.25A at 24V. A 200W 24V XLG could be a capacity candidate, subject to its datasheet, controller rating and the actual wiring. Feed separate reels according to the strip’s instructions rather than assuming a 10m end-to-end run is acceptable.

A 200W 12V supply is still the wrong voltage for this strip. Check voltage at the far end under load; plan power injection or separate parallel feeds as the manufacturer requires.

IP67 does not change electrical compatibility

Both 12V and 24V XLG variants may be described as IP67 on Glowfy’s current listings. This rating concerns the driver enclosure. Cable joints, strip cut ends, connectors and controllers each need their own environmental protection. Outdoor placement must also respect temperature, mounting and service access instructions.

A larger rated unit can draw significant input current and have installation requirements on its mains side. A competent person should assess and complete that work, including isolation and protective measures.

Purchase checklist for the correct variant

Before ordering, write down the following and compare it with the live product listing and delivered label.

• Every LED product’s specified DC input voltage.
• Total connected watts and current, including controller load where applicable.
• Exact XLG variant and output mode, voltage, rating and thermal derating.
• Branch lengths, wire section, connector and controller current ratings.
• IP protection for the driver and every exposed connection.
• A full-load test plan and service access.