LED Strip Wiring: Can I Directly Connect 20A 5V DC?

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Discussion Overview

The discussion revolves around the wiring and power requirements for a 5-meter LED strip that operates at 5V and is rated for 18W per meter. Participants are exploring whether it is safe to connect a 20A power supply directly to the strip and the implications of current distribution, connectors, and wiring gauge.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Exploratory

Main Points Raised

  • One participant questions whether a 20A 5V DC power supply can be connected directly to the LED strip, expressing concern about potential damage.
  • Another participant clarifies that the LED strip will draw the current it needs from the power supply, which is estimated to be around 18A, depending on temperature.
  • There is a suggestion that the ground wiring does not need to be of large gauge, as it is connected to the local Earth or ground at the power supply.
  • One participant expresses skepticism about the connectors available for the strip, noting that they typically support lower currents, suggesting further investigation is needed.
  • Another participant proposes that soldering larger gauge wire directly to the LED strip could be a solution, questioning the necessity of the included connectors.
  • Concerns are raised about the maximum current capacity of the LED strip's PCB track width and connectors, with a warning against exceeding these limits.
  • There is a discussion about whether the 18W rating refers to per meter or for the entire 5-meter strip, with some participants seeking clarification.
  • One participant mentions anecdotal evidence from customer comments regarding the current draw of similar LED configurations, suggesting that pushing 20A through the strip may not be reasonable.
  • Another participant notes that the circuit diagram indicates feeding the strip from both ends, which could reduce the current through connectors.
  • There is a question about the necessity of connecting both ends of the strip to power and ground, with responses indicating that it depends on the current ratings of the strip and connectors used.

Areas of Agreement / Disagreement

Participants express differing views on the safety and feasibility of connecting a 20A power supply directly to the LED strip. There is no consensus on the maximum current capacity of the strip or the necessity of using connectors versus direct soldering.

Contextual Notes

Participants highlight uncertainties regarding the specifications of the LED strip, including the maximum current ratings of connectors and PCB tracks, as well as the implications of current distribution when powering the strip from one or both ends.

Geranimo
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Hi, I want to buy 5 meter 60 LEDs/m LED strip here and this is the recommended circuit. The strip needs 5V. In their description they say 60 LED is 18W so I need 20A DC power supply.

Can I send 20A 5V DC directly in the strip? Will it fry the strip? Also, for the ground wiring, is this where the electrons come back in the power supply with 0V? If so I suppose I don't need a big AWG wire? How to calculate how big AWG I need for ground wire?
 
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Geranimo said:
The strip needs 5V. In their description they say 60 LED is 18W so I need 20A DC power supply.
Input voltage: DC5v; 60 leds/m; dissipates 18 watt/meter; 5 metre * 18W = 90 watt; 90W/5V = 18 amp

Geranimo said:
Can I send 20A 5V DC directly in the strip? Will it fry the strip?
The LED strip will take what current it needs from the fixed 5V supply. That will be about 18 amps, it will vary with temperature.
You will connect the 0V and the +5V to the LED strip with two wires of the same gauge. A 20 amp low voltage circuit will need two wires, each with a cross section of 4mm2.

The 0V side of the 5V circuit will be connected to the local Earth or ground at the power supply. The ground and control wires from the controller to the LED strip can be much thinner than the power supply cables.
 
Geranimo said:
Can I send 20A 5V DC directly in the strip?
I think it's a 'no'.
I admit it's just a googled knowledge, but the strip connectors I could find are only for a few A current. There was one for 5A, and that was already 'high current support'.

Some more digging will be required I think. What kind of connectors/wires does those strips has and what is the maximal current for them?
Then you will have to limit the strip length for one connector accordingly.
 
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But the isn't the included connector just for convenience? I could just solder my bigger AWG wire that supports 20A directly on the first LED?
 
The track width on the flexi PCB of the LED strip is also designed with some kind of maximal current in mind.
Which is most likely something similar like the actual wires and connectors.
I would not try to hack this. Not at 5A <-> 20A disparity.
 
Are you sure that is 18w/m, or 18w for all 5m?
 
18w / 60 LEDs

Also I read the adafruit section on powering their neopixels and all they say about high amps is that I may have discoloration at the end of the strip, nothing on anything frying...
 
One of one on the customer comments on the link you provided said that 144 LEDs drew about 2a. That is close to 18w/300 LEDs.

Besides, pushing 20a up that strip doesn't sound reasonable.
 
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anorlunda said:
Besides, pushing 20a up that strip doesn't sound reasonable.
It is important to note that the circuit diagram shows each long LED strip being fed from both ends. That will halve the current through the connectors to 9 amp.

The power cable from the power supply will need to carry and distribute the full current.
 
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  • #10
But do I really need to connect both ends to ground and 5V for a single 5m strip?
 
  • #11
Geranimo said:
But do I really need to connect both ends to ground and 5V for a single 5m strip?
That will depend on the current rating of the replicated strip and the current rating of the connectors you use. It will still work if you drive it from one end, but the connectors to, and the conductors on the strip will run hot, so the reliability and efficiency will be less when driven from only one end.
Remember that the digital data stream addresses the individual current controllers on each RGB LED, so the data must be linked along the strips in series.
 
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