Mean Well RSP-320-5 Power Supply
5V 60A · 300W rated, not 320W · active PFC PF>0.95 · fan-cooled with speed control · 5000m altitude · 215 × 115 × 30mm

The RSP-320 Series: A 320W Name and Only One Model That Reaches It

The RSP-320 series spans twelve voltages from 2.5V to 48V. The four lowest-voltage models share a 60A current ceiling, and the highest-voltage models land near 321W. The 5V model sits in the 60A group, which is why it delivers 300W rather than the 320 the name suggests.

Two models in this series share the same 300W rating: the 5V at 60A and the 7.5V at 40A. If you are comparing quotations on wattage alone they look identical, but the 7.5V model is 88% efficient against the 5V model’s 83% — a five-point difference that shows up as heat inside the cabinet, not on the invoice.

Why the RSP-320-5 Has a Fan and the RSP-200-5 Does Not

This is the most useful thing to understand about the RSP range, because it decides which models are appropriate for dusty, sealed or acoustic-sensitive cabinets. The transition from fanless to fan-cooled happens between 40A and 60A at 5V, and the datasheet efficiency figures explain why.

The heat column is arithmetic derived from the datasheet efficiency figures — output watts divided by efficiency gives input watts, and the difference is the loss. It is not a figure MEAN WELL prints on the datasheet. Shown here because it makes the cooling change legible: doubling the output power while efficiency drops four points more than doubles the heat the case has to shed.

What fan speed control actually does for you

• Noise tracks load, not the calendar. The fan runs at the speed the thermal load requires rather than at a fixed maximum. A screen idling at low brightness is quieter than the same screen at full white.
• Fan life is the maintenance item. A fan-cooled supply has a moving part with a finite service life that a fanless supply does not. On a screen expected to run for a decade, budget for the fan as a wear item.
• Airflow path matters more than the fan. The mechanical drawing marks the air flow direction. Mount the unit so air enters and exhausts freely; a fan pushing into a blocked duct is worse than no fan, because the supply still assumes forced airflow for its rating.
• Dust is now a factor. A fan draws cabinet air through the case. In a dusty installation that means planning filter or cleaning intervals, or specifying the optional conformal coating.

RSP-320-5 at 5000 Metres: What the Altitude Rating Changes

The datasheet lists operating altitude up to 5000 metres as a headline feature, and it is one of the few specifications on this page that most competing listings omit entirely. It matters because altitude affects cooling in two separate ways.

• Air is thinner, so it carries less heat. Convective cooling depends on air mass flow, not air volume. At 5000m the same fan moves the same volume but a substantially lower mass of air, so the same fan speed removes less heat.
• The derating rule is stated on the datasheet. MEAN WELL applies an ambient temperature derating of 5°C per 1000m with fan models above 2000m. That is a hard, published number — not an estimate. Read it before quoting this supply into a high-altitude project.
• Apply it to the derating curve. Take the worst-case cabinet ambient, add 5°C for every 1000m above 2000m, and read the load limit at the resulting temperature. A site at 3000m effectively moves the whole curve 5°C to the left.
• High-altitude sites are usually also cold sites. Mountain and highland installations often have low ambient temperatures, which offsets part of the derating. Use the real measured ambient, not a summer design maximum carried over from a sea-level project.

The datasheet does not publish a separate derating curve per altitude — it publishes the 5°C/1000m rule and expects it to be applied to the standard curve. That is the method above. If a high-altitude project is load-critical, raise the site altitude at quotation and we will confirm the derated figures rather than leave the arithmetic to the installation stage.

How Many LED Modules Can One RSP-320-5 Power?

No supplier can answer this without knowing your module. The count depends on the maximum power rating of your LED module from its own datasheet, the number of modules on the supply, and the thermal headroom you leave — which on a fan-cooled unit is a real constraint, not a formality.

1. Start from the real rating. 300W at 5V, which is 60A.
2. Apply a load ceiling. A common planning rule in LED cabinet builds is to keep continuous load at or below about 80% of rated output — roughly 240W, or 48A, on an RSP-320-5. This is an engineering convention rather than a MEAN WELL figure; treat it as a starting point and confirm it against your project’s thermal and warranty conditions.
3. Divide by the module’s maximum power, taken from the module datasheet rather than a marketing page — full white is exactly the condition a screen is commissioned under.
4. Check the derating curve at real cabinet ambient, including the altitude adder if the site is above 2000m.
5. Check the current path. 48A has to leave through the terminal block and reach the modules. Confirm wire gauge, terminal rating and the number of feeds.
6. Check the capacitance on the 5V rail. The datasheet strongly recommends external output capacitance not exceeding 5000µF, and the 5V model is inside the list this applies to. If the cabinet carries a large capacitor bank, raise it at quotation.

Worked as an Illustrative Example — substitute your own module figures; these numbers are for the arithmetic only:

Parallel operation is not a function this model provides. If the screen outgrows one supply, split the cabinet into independently supplied sections rather than paralleling two RSP units. For the control and signal side of the same cabinet, the LED control system collection covers how sending cards, receiving cards and processors are powered and wired alongside the supplies.

Conformal Coating on the RSP-320-5: Coated Models for Humid Sites

The RSP-320 series lists optional conformal coating as a series feature. The coated variant is the same supply with its circuit board treated, and it addresses the one weakness a fan-cooled design introduces: a fan pulls cabinet air through the case, and cabinet air carries dust and moisture with it.

When to specify the coated version

• Dusty installations — the main reason on a fan-cooled model. Every hour the fan runs, it draws cabinet air across the board. In a workshop, a foundry or a roadside cabinet, that deposits contamination on live circuitry.
• Coastal and high-humidity sites. Salt-laden or persistently damp air builds a conductive film over time. A coating interrupts that path.
• Screens that condense. An outdoor cabinet that cools overnight can condense moisture inside. Coatings are the standard board-level mitigation.
• But coating is not a substitute for enclosure design. It protects the board. It does not make the supply waterproof, does not change its IP rating, and does not remove the need to manage dust and condensation in the cabinet itself.

RSP-320-5 Troubleshooting: Fan Noise, Hiccup Mode and Start-Up Delay

Three protection behaviours differ from each other on this model, which is why the same visible symptom can have unrelated causes. Work through them in order; each step separates one cause from the others.

The fan is louder than expected, or runs continuously

• Possible cause: this is a fan-speed-controlled unit, so the fan tracks thermal load. Continuous high-speed running usually means the supply is genuinely hot, not that the control is faulty.
• How to check: measure cabinet ambient and case temperature. If ambient is above roughly 50°C, the fan is doing its job.
• Fix: improve cabinet ventilation or reduce the load per supply. Do not disconnect or obstruct the fan — the rating depends on forced airflow.

Output drops out and recovers on its own, repeatedly

• Possible cause: overload hiccup mode at 105–135% of rated power, or over-temperature protection. Both recover automatically, so both look identical from outside.
• How to check: measure DC current with the screen at full white, then measure the case temperature and cabinet ambient. A clamp meter and a thermometer usually separate the two.
• Fix: if current exceeds the planning ceiling, split the load across an additional supply. If the cabinet is hot, fix the airflow — and check the fan is actually turning.

No output at all, and it stays off after a power cycle

• Possible cause: over-voltage protection has latched. Unlike the overload protection, OVP on this model shuts the output down and requires a re-power to recover.
• How to check: remove the load and re-power. If the output returns with no load connected, the trip was load-related rather than a supply failure.
• Fix: find what drove the output above 5.75–6.75V — typically a load fault or a wiring error — and correct it before reconnecting.

The screen takes two to three seconds to come on after mains is applied

• Possible cause: nothing is faulty. Set-up time is 1500ms at 230VAC and 3000ms at 115VAC, plus a 50ms rise time.
• How to check: measure the delay from mains applied to output stable, and compare with the datasheet figure for the site voltage.
• Fix: no fix required if the delay matches the specification. If control logic assumes supplies are ready sooner, adjust the sequence timing rather than replacing hardware.

Screen brightness drops or pixels discolour at the far end of a run

• Possible cause: voltage drop along the DC path, not a supply fault. At 5V and 60A, cable resistance takes a proportionally large bite out of the delivered voltage.
• How to check: measure voltage at the supply terminals and again at the input of the last module on the run. The difference is the drop.
• Fix: shorten the run, increase the conductor cross-section, or split the feed. Then trim the output adjustment so the module input reads its specified 5V under load — not so the supply terminal reads 5V.

The supply trips on start-up but runs fine once loaded

• Possible cause: external output capacitance exceeding the recommended ceiling. The datasheet strongly recommends not exceeding 5000µF on the 5V model.
• How to check: total the capacitance across the 5V rail — module-side capacitors included, not just the ones next to the supply.
• Fix: reduce the bank, or spread the capacitance across separately supplied sections rather than concentrating it on one supply.

Mean Well RSP-320-5: Frequently Asked Questions