One Big Power Supply vs Multiple Smaller Ones

ledpower

I'm remodeling my kitchen and decided to get LED strips. I already know the necessary power for my LEDs, but I want to decide whether to power them all from one source or multiple sources. These are the zones

1 zone: 8 meters 120LEDs 5050 double strip (power supply will connect in the middle on the fourth meter to avoid voltage drop)
2 zone: 4 meters 120LEDs double strip
3 zone: same as zone 1

Since the power supplies and wires will be all behind cabinets I have the option to choose whether to power them all from one power source or get three separate ones for each zone.

First scenario will be:

1 power supply 240Watt for zone 1
1 power supply 120Watt for zone 2
1 power supply 240Watt for zone 3

Second Scenario would be:

1 600Watt power supply for zone 1, 2 and 3.

I'm aware that both will work great. 8 meter zones will be connected in the middle to avoid voltage drop.

In terms of price it seems like multiple power supplies is the better option, at least that's what Chinese suppliers on ebay say. I'm pretty sure that the 600 watt must have a fan which may do produce some noise. Some 240W power supplies I've found are with passive cooling so in terms of noise, separate ones might also be better. And if something happens and some of them dies, I can only replace the one that's dead.

What do you think are there any advantages to having one big power supply for all of the leds?

Best Answer

I'd go for many smaller ones.

  • Cheaper.
  • Quieter (no fans)
  • Cheaper to replace in case of failure (you just replace one instead of all of them)
  • Better control over voltage drop (you can put each PSU closer to the load to extend efficient mains wires and shorten inefficient 12V wires)
  • Better control over cooling (you can put them farther apart to disperse heat production)
  • Ability to shut down (disconnect from mains) parts of the system to increase efficiency (underloaded PSUs are very inefficient)

Single large PSU is unavoidable for single large load - that's why they're more expensive.

As a side note, I am bit concerned about the "behind cabinets" part. A 240W PSU running at 80% efficiency will dissipate almost 50W on it's own - that requires pretty good access to fresh air. No problem if they are between cabinet and a wall and this space is open at the top and the bottom - they will create enough draft on their own. But if you close the space, they'll cook themselves, greatly shortening lifespan.

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