If you are choosing between the Mean Well LRS-350-24 power supply 350W 24V and a Mean Well 24V 30A power supply model, here is what I learned from years of signing purchase orders: the model number should come after the layout, not before it.

I manage procurement for a lighting systems company, so I look at total installed cost. A supply that costs less per watt is a poor deal if it makes the wiring harder, the enclosure bigger, or the service call more expensive. This article is for 24VDC constant-voltage lighting loads: LED tape, linear light bars, low-voltage fixtures, and system lighting. If your fixture is a constant-current module that says 700mA or 1,050mA, stop here and pick a Mean Well LED driver instead.

The way I sort through options when someone asks about Mean Well for house spotlight or system lighting work is simple. Which of these sounds like your job?

  • A local 24V load that stays under 350W. This usually points to the LRS-350-24.
  • Multiple lighting zones with controls and long wire runs. This usually points to more than one smaller supply, not one giant power supply.
  • One central 24V bus that really needs 30A. This points to the RSP-750-24.

Scenario 1: The LRS-350-24 Is Probably Enough

The Mean Well LRS-350-24 is rated at 350W, 24V and 14.6A according to the published Mean Well spec sheet (meanwell.com). If that sounds low compared with a 30A power supply, remember what 14.6A can do. A high-output light bar drawing 18W per foot uses about 9A on a 12-foot run and 12A on a 16-foot run. A set of exterior house spotlight fixtures at 18W each uses about 9A for 12 fixtures. The 350W unit has useful margin for both cases.

I have seen oversizing become a habit. Someone quotes a 24V 30A model because the phrase future-proof gets repeated. In my experience that extra capacity usually means a bigger enclosure, a larger breaker, heavier wire, and sometimes a fan you did not plan on. Meanwhile the light load that needs 9A could be served by a smaller supply that is easy to replace. Future-proofing often works better as an extra empty conduit or a second location for a supply.

The practical rule: if all loads are close together and the steady-state current is below 12A to 13A, the LRS-350-24 is usually enough. Above that, or in a nearly sealed enclosure at high ambient temperature, move up to a second supply or the 750W class.

Scenario 2: System Lighting Changes the Whole Equation

Once you move from one fixture group to actual system lighting, the 350W versus 30A question becomes a layout question. The tendency is to total every fixture watt and buy one large supply. That feels efficient. It often is not.

With a single 30A bus at one end of a building and 24V fixtures at the far end, you are fighting voltage drop before you even think about enclosure size. A large power supply also creates a single point of failure for the whole lighting system. In operations, distributed supplies usually make more sense.

Last year I priced a project two ways. The first bid was one Mean Well 24V 30A supply in a central enclosure, feeding several zones. The second was three DIN-rail Mean Well supplies, each located near its own zone. The first solution was cheaper in hardware. After the electrician added larger conductors, longer homeruns, and a fan-cooled enclosure, the second solution was about 18% cheaper overall. It also meant one zone could keep working while another had a supply replaced.

If the lighting is dimmed or controlled, read the product page before you buy. Mean Well's LED driver families include many models with 3-in-1 dimming (resistor, PWM, and DC voltage control). A plain switching power supply such as the LRS-350-24 is not that driver. It can feed a controlled DC bus, but it should not be treated as a dimmable LED driver just because it is made by Mean Well.

Scenario 3: When a 24V 30A Model Makes Sense

Now we get to the actual search phrase. A Mean Well 24V 30A power supply model means the load needs 720W at 24V. The model I usually quote is the Mean Well RSP-750-24, rated 24V and 31.5A according to the published spec (meanwell.com). This is the right answer for a centralized 24V bus that feeds multiple high-current light bars, large signage, or a row of high-brightness fixtures where splitting into several smaller power supplies would make the control wiring more complicated.

The phrase what is the brightest light bar? comes up in almost every high-output LED project. Brightness is not created by the power supply. It is determined by the LED chips, the driver current, and the optics. But a high-output light bar still consumes a measurable current. If a bar draws 18W per foot, a 40-foot system needs 720W, which is 30A. That is when the RSP-750-24 stops sounding like overkill.

Do not try to create 30A by connecting two LRS-350-24 supplies in parallel. The LRS series is not designed for parallel load sharing. If the load is genuinely centralized, use the RSP-750-24. If the load can be split by physical location, treat each half as its own system and use separate LRS supplies. That is safer and cheaper in the long run.

How to Tell Which Scenario You Are In

Here is the load-sheet process I use on the jobs I quote:

  1. Check the fixture label. If it says 24VDC, continue. If it lists a drive current, buy an appropriate LED driver instead.
  2. Add up fixture watts at full output and divide by 24. That gives nominal amps.
  3. Draw the physical layout. Long 24V runs fail from voltage drop before they fail from power supply capacity.
  4. If the load is in one location and under about 350W, use the LRS-350-24.
  5. If the load is spread across zones, use one supply per zone. For house spotlight systems with separate outdoor areas, that often means smaller DIN-rail supplies.
  6. If every load is fed from one central panel and the current really reaches 30A, use the RSP-750-24 class.

When I started in this role, I treated power supplies as commodities and compared them by price per watt. I still kick myself for a 2023 install where I approved a central 24V bus based on total watts and ignored voltage drop. The supply was correct. The wire run was too long. The job needed an extra supply, and the customer paid for a second visit.

The Mean Well model is rarely the problem. The problem is whether the supply matches the physical layout, the control scheme, and the real load. Match those three things first, and the choice between an LRS-350-24, a few smaller DIN-rail supplies, or a 24V 30A model becomes an easy decision.