Guide
LED IP65 or IP67, 12 V or 24 V? Choosing for Signs
LED IP classes (IP65, IP67), the difference between 12 V and 24 V, voltage drop and choosing the right power supply for outdoor signs.
ByAsta Reklam
Published:
3 min read
In this article(6)
IP65 and IP67 are protection classes against dust and water. Both are dust-tight. IP65 withstands water jets from any direction; IP67 withstands temporary immersion (1 m for 30 minutes). 12 V and 24 V are the output voltage. At the same power, 24 V draws half the current and loses less voltage.
IP classes
| Class | Dust | Water | Typical use |
|---|---|---|---|
| IP65 | Dust-tight | Water jets from any direction | Signs and facades exposed to rain |
| IP67 | Dust-tight | 1 m immersion, 30 min | Places where water can collect |
IP67 does not automatically include IP65, because jets and immersion are separate tests. “IP65/IP67” on a label means both.
IP65 or IP67?
IP65 is enough for most rain-exposed signs and channel letters. Choose IP67 where water can pool. Failures usually happen at cable entries and joints, so use watertight connectors.
Our products: LED module (IP65 and IP67), LED strip (outdoors, IP65 or higher), outdoor power supply (IP67, 12 V, 35–600 W; also 24 V 300 W) and rainproof adapter (60–700 W; IP class on the label).
12 V or 24 V?
| 12 V | 24 V | |
|---|---|---|
| Current at equal power | Higher | Half |
| Voltage drop | Larger | About half |
| Single-end feed (strip) | About 5 m (product page) | Longer (typical; check datasheet) |
LED and power supply must have the same voltage, or the LED can be destroyed.
Voltage drop example
Copper cable: drop (V) ≈ 2 × length (m) × current (A) ÷ (56 × mm²). A 5 m strip at 14.4 W/m (72 W) on 3 m of 1.5 mm² cable gives:
- 12 V: 6 A, drop ≈ 0.43 V (about 3.6%).
- 24 V: 3 A, drop ≈ 0.21 V (about 0.9%).
About 3% is a common limit (typical). To reduce drop, use shorter or thicker cable, feed from both ends, split the load, or move to 24 V.
Power supply size
Multiply total LED power by 1.25 and pick the next step up: 432 W × 1.25 = 540 W, so a 600 W supply. The LED calculator does this. For price and stock, ask your branch or contact us.
FAQ
Is IP65 enough for channel letters?
Usually yes. Where water can collect, choose IP67.
Can I connect a 12 V strip to a 24 V supply?
No. The voltage mismatch can burn out the LEDs.
How do I reduce voltage drop?
Thicker cable, a shorter run, feeding from both ends, or 24 V.
Sources: IP Code (IEC 60529), Wired4Signs.
This article contains general information; confirm dimensions and technical values before production.
