LED Display Power Supply
Mean Well 5V range, verified against the datasheets · 12 models from 150W to 500W · real wattage, PFC, cooling and input range

Why Mean Well 5V Model Numbers Overstate the Wattage

Mean Well names a series after the highest wattage any model in it can reach. That figure is normally achieved by the highest-voltage output, where the current needed for the same power is lowest. The 5V model shares the family’s current ceiling, so it lands short. The pattern repeats across all four families, which is why it is a rule and not an accident of one part number.

Here is the complete 5V range, with the series number beside the output the datasheet actually specifies at 5V.

Seven of twelve fall short. Five are exact. The exact ones are not a coincidence either: LRS-200-5, RSP-150-5, RSP-200-5 and UHP-200-5 all sit at the bottom of their families where the current ceiling and the series wattage happen to meet, and NEL-400-5 is a single-model series named after its own output.

Grey bars are the series number, blue bars are models whose real 5V output matches the name, and dark red bars are models that deliver less.

All 12 Mean Well 5V Power Supplies Compared

Every figure below is taken from the MEAN WELL datasheet for that specific 5V model — not from the series datasheet, because series headlines quote the best model in the family and that is the number buyers are usually misled by.

Two patterns stand out once the table is side by side. Efficiency and cooling move together. The three fanless UHP models top the list at 90–91%, and the models that need forced air sit at 83–87%. Efficiency is not a green credential here; it is the number that decides whether a fanless case is physically possible. PFC is a family decision, not a model decision. Every RSP and UHP model has an active PFC stage and no LRS or NEL model does.

Fanless or Fan-Cooled LED Display Power Supply: Which Survives Your Cabinet?

This decision is less about the supply than about the cabinet it goes into, and it is the one buyers most often get backwards. A fanless supply is not automatically the more reliable choice — it is the more reliable choice in the right enclosure.

When fanless is the correct answer

The UHP family is fanless and needs no air path through the case. That makes it the right choice for dusty, humid or wash-down environments, for acoustic-sensitive rooms such as studios and boardrooms, and for any installation where the supply is sealed inside a cabinet with no filtration. Nothing rotates, so there is no bearing to wear and no fan to draw contaminants across the boards. The trade-off is a mounting rule: the UHP models must be installed onto a flat aluminium plate or a cabinet acting as one, with a suggested plate of 300 × 300mm for the UHP-200-5 and 450 × 450mm for the UHP-350-5 and UHP-500-5, mounted centrally on an even surface. At 90% efficiency and 400W output the UHP-500-5 still has roughly 40W of heat to move through that plate.

When fanless is a mistake

A fanless supply in a sealed, unventilated box is worse off than a fan-cooled one, because convection needs somewhere for the heat to go. If the enclosure cannot reject heat, the fanless unit simply soaks. Two LRS models are fanless — the LRS-200-5 and the RSP-150-5 and RSP-200-5 in the RSP family — and each of them carries a derating curve that assumes free air around the case.

What a fan actually costs you

In a fan-cooled supply the fan is typically the first component to fail, and at 5V it runs continuously because the output stage is always hot. On the LRS-450-5, LRS-600-5 and the RSP models, the fan is switched by an internal sensor at around 50°C, which softens the duty cycle indoors but does nothing in a warm cabinet where the sensor never drops back below the threshold. If the cabinet is accessible for maintenance and the air is clean, a fan-cooled supply is the cheaper way to reach high current. If it is not accessible, specify fanless and design the thermal path instead.

LRS vs RSP vs UHP vs NEL: Which Mean Well Series Fits Your Project

The four families are not a ladder from cheap to expensive. They are four different answers to the same question, and the right one depends on which constraint binds hardest on your project.

Two of these comparisons come up often enough to state plainly. RSP-500-5 against LRS-600-5: the RSP delivers 90A against the LRS’s 100A, but it adds PFC, specifies lower ripple and noise, and on 110V mains the LRS is derated to 90A and 450W anyway — so outside 230V markets the two are closer than their names suggest. UHP-500-5 against RSP-500-5: the UHP gives 400W fanless against the RSP’s 450W with a fan. You are trading 50W for the removal of the only moving part, and in a sealed outdoor cabinet that trade is usually correct.

Certifications to Check Before You Specify a Power Supply

The four families do not carry the same approvals, and the differences are large enough to decide a project. The distinctions below are the ones that actually appear in tenders.

• Safety approval is the baseline. The LRS, RSP and UHP models on this page are certified to UL 62368-1, the current standard for audio/video and IT equipment. NEL-400-5 carries UL 62368-1 and EAC TP TC 004 only — there is no European safety approval on its datasheet.
• EMC is where the families diverge most. RSP and UHP models list EN55032 emissions and EN61000-4 immunity series approvals. NEL-400-5 lists EAC TP TC 020 for both emission and immunity, which is a Eurasian customs-union approval and not a European one.
• Harmonics compliance follows PFC. If a project references EN61000-3-2, only the RSP and UHP families can meet it, because only they have a PFC stage to begin with.
• Read the ratings that are easy to miss. The RSP-320-5 is rated for operation at up to 5000m altitude, which matters for highland installations. RSP-200-5 offers an optional conformal coating, which is the correct answer for coastal or humid sites where a fanless supply alone is not enough protection.

Documentation practice matters as much as the certificate list. For any of these models, ask for the batch’s own documentation from the manufacturer’s website rather than trusting a listing photograph — the serial and date-code check is the only reliable way to confirm provenance.

LED Display Power Supply Troubleshooting: Five Failures

Most power-supply faults in an LED display present as something else first, which is why they get misdiagnosed as control problems. These five cover the large majority of field failures on the models in this range.

The display dims or flickers on high-brightness content

This is usually an undersized supply rather than a control fault. Full-white content draws maximum current, the 5V rail sags, and the driver ICs respond by losing brightness uniformity. Measure the 5V rail at the far end of the cabinet under a full-white test pattern rather than at the supply terminals; voltage drop across the cabinet distribution is the usual culprit, and if the rail itself is low at the supply, the unit was sized on the model number instead of the real output.

The supply shuts down after an hour or two, then recovers

Over-temperature protection, almost always caused by a cabinet whose real ambient is far above the bench figure the derating curve was read at. A fan-cooled unit in a dusty cabinet makes this worse, because the fan is moving less air than it did when new. Check for blocked or clogged fans and confirm the installation ambient against the curve.

Nothing starts, but the supply is new

On the four LRS models, check the 115/230V selector switch before anything else. A correctly built cabinet with the switch in the wrong position behaves exactly like a dead supply. This failure is common enough on multi-unit jobs that the switch position is worth photographing at commissioning.

The supply powers up repeatedly in a hiccup cycle

Hiccup mode is the intended response to overload or short circuit, not a defect. It means the load is drawing more than the supply will deliver, or there is a short on the 5V distribution. Disconnect the load in sections to isolate it. Worth noting for specification: some models recover from over-voltage protection automatically, while others require the input to be cycled, so a fault that clears itself on one model may need a manual re-power on another.

The supply runs hot with a load well inside its rating

Check efficiency and ambient together. At 84% efficiency a 450W output produces roughly 86W of heat inside the case — the arithmetic follows directly from the datasheet efficiency figure, and it is why the lower-efficiency models in this range need forced air. If the load is genuinely modest and the cabinet is still hot, the supply is the wrong family for the enclosure rather than the wrong wattage.

If the supply checks out and the fault remains, the next place to look is the signal chain rather than the power chain. Sending cards, receiving cards and the processor can produce symptoms that look identical to a power fault, and the LED control system collection covers that side of the cabinet.