Mean Well RSP-500-5 Power Supply
5V 90A · 450W rated, not 500W · active PFC PF>0.95 · remote ON/OFF & remote sense · 18ms hold-up · 230 × 127 × 40.5mm

The RSP-500 Series: Eight Models, Three of Them Capped by the Same 90A

The RSP-500 series covers eight voltages from 3.3V to 48V. The three lowest share a 90A current ceiling, and no model in the series reaches exactly 500W — they range from 297W to 504W, with the higher-voltage models landing just above the name.

Efficiency follows the same pattern as the rest of the range: the 5V model is 84% against 90.5% for the 48V model. Delivering 450W at 84% efficiency means roughly 86W dissipated as heat inside the case — arithmetic from the datasheet efficiency figures, not a published loss figure — which is why this model has a fan that runs continuously.

RSP-500-5 Remote Sense: Why 0.3V Compensation Matters More at 5V

Remote sense is the reason to choose this model over the RSP-320-5, and it is the feature most often left out of reseller listings entirely. It works by measuring the voltage at the load rather than at the supply terminals, and adjusting the output to hold the load voltage correct.

The arithmetic that makes it necessary

The datasheet states the remote sense function compensates voltage drop on the load wiring up to 0.3V. On a 48V rail, 0.3V is six tenths of one percent — a detail. On a 5V rail it is six percent of the entire supply voltage, and six percent is the difference between modules receiving their specified voltage and running visibly dim at the far end of a run.

Wiring the sense lines

• CN100 is a 4-pin connector — pin 1 is −S, pin 2 is +S, pin 3 is RC− and pin 4 is RC+. The mating housing is an HRS DF11-4DS or equivalent.
• Connect −S to the negative terminal of the load and +S to the positive terminal, at the load end of the run rather than at the supply.
• Twist the sense pair. The datasheet specifies that the +S and −S leads should be twisted together in a pair to minimise noise pick-up. Sense lines carry a signal, not power, and they are measuring a voltage that the supply will act on.
• Never leave sense lines unterminated and connected. An open or reversed sense connection makes the supply regulate against a wrong reference. If remote sense is not being used, the datasheet’s default configuration applies.

Remote ON/OFF on the same connector

This model also has built-in remote ON/OFF control, driven electrically or by a dry contact between RC+ (pin 4) and RC− (pin 3). The logic is 0∼0.8VDC or open for power ON, and 4∼10VDC for power OFF. The datasheet’s function diagram shows an external supply driving the input at 6∼20mA through a switch.

Note that between the RSP-150-5, RSP-200-5, RSP-320-5 and RSP-500-5, the RSP-500-5 and RSP-150-5 have remote control and the RSP-200-5 and RSP-320-5 do not — and only the RSP-500-5 adds remote sense on top. If a control scheme switches supplies over a signal line, those are the two models in the 5V range that can do it natively.

RSP-500-5 Overload Protection: Constant Current Limiting, Not Hiccup

This is a real functional difference from the other RSP 5V models, and it changes what a screen does when it is overloaded.

Why constant current limiting is often the better failure mode on a screen

• No on-off flicker cycle. Hiccup mode produces a repeating shutdown and restart, which on a video wall reads as a strobing fault. Constant current limiting produces a steady, dimmer image.
• The screen stays diagnosable. A dim screen still shows which modules are lit, which helps locate a shorted module. A screen cycling on and off shows nothing useful.
• The current is capped, so the supply is protected either way. Both behaviours prevent damage. The difference is what the operator sees while the fault exists.
• But a dim screen can be mistaken for a brightness problem. If a screen on an RSP-500-5 is uniformly dim and the fault is not obvious, measure the DC current before assuming anything else — the supply may be sitting in current limit.

How Many LED Modules Can One RSP-500-5 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, the thermal headroom you leave, and — on a 90A supply — the voltage drop down the DC run.

1. Start from the real rating. 450W at 5V, which is 90A.
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 360W, or 72A, on an RSP-500-5. This is an engineering convention rather than a MEAN WELL figure; confirm it against your own 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 the condition a screen is commissioned under.
4. Check the derating curve at real cabinet ambient. If the site is above 2000m, the datasheet applies an ambient derating of 5°C per 1000m for fan models.
5. Size the DC conductor for 72A and then enable remote sense. Remote sense corrects up to 0.3V of drop; it does not excuse an undersized cable.
6. Plan the heat. Roughly 86W per supply at full load has to leave the cabinet, and the fan is always on at 5V.

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.

RSP-500-5 Certifications and EMC: Class B with EN61000-6-2 Immunity

The RSP-500-5 carries the modern safety set and a broader immunity listing than the models below it in the range.

Why EN61000-3-2 is the line that matters commercially

EN61000-3-2 is the harmonic current emissions standard, and it is the reason the RSP family exists alongside the LRS family. MEAN WELL’s LRS datasheets state plainly that those units do not meet the harmonic current requirements of BS EN/EN61000-3-2 and set out conditions under which they should not be used in the European Union. The RSP-500 datasheet carries no such restriction — it lists compliance, because the active PFC stage is what makes compliance possible.

Two certification points to check rather than assume

• EN61558-1/2-16 is not on this datasheet at all. On the RSP-320 datasheet those approvals are listed for 12V-or-higher models only; on the RSP-500 datasheet they do not appear. If a tender names EN61558, this series does not satisfy it and that has to be resolved before the specification is fixed.
• The EMC tests are component-level. MEAN WELL specifies this unit as a component to be installed into final equipment and states that the final equipment must be re-confirmed as still meeting the EMC directives, referring to the manufacturer’s own EMI testing guidance for component power supplies. An RSP-500-5 on a bench is a certified component; inside a screen it is part of a system whose EMC must be validated in its own right.

RSP-500-5 Troubleshooting: Dim Output, Latched Shutdown and Sense Faults

On this model the constant-current-limiting overload behaviour adds a symptom that does not appear on the RSP-200-5 or RSP-320-5, and the remote sense function adds a class of fault all of its own. Work through these in order.

The whole screen is uniformly dim but still running

• Possible cause: the supply is sitting in constant current limiting at 105–130% of rated power. Unlike the hiccup-mode models below it, this supply does not switch off — it holds at the current limit, so the output voltage sags and the screen dims.
• How to check: measure DC current at the output. If it is pinned at the limit rather than tracking load, the supply is limiting.
• Fix: find the overload — a shorted module, a wiring fault or simply too many modules on the supply — and correct it. Do not compensate by turning the output adjustment up; the supply will still limit.

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

• Possible cause: over-voltage protection has latched. OVP on this model shuts the output down and requires a re-power to recover, unlike the overload and over-temperature protections, which both recover automatically.
• Also check the remote control input. If RC+ and RC− are being driven between 4 and 10VDC, or if the wiring to CN100 is disturbed, the supply is being told to switch off. A remote-control fault looks exactly like a supply failure.
• How to check: disconnect the load and re-power. If the output returns, the trip was load-related. Then verify the voltage between RC+ (pin 4) and RC− (pin 3) with the control circuit in its intended state.
• Fix: correct what drove the output above 5.75–6.75V, or correct the remote-control signal, before reconnecting.

Output voltage is wrong at the supply but correct at the load, or vice versa

• Possible cause: remote sense is active and is regulating against the load terminals rather than the supply terminals. This is correct behaviour, not a fault.
• How to check: measure at both ends. With sense connected, the load voltage is the one being held correct and the supply terminal voltage will read higher by the amount of the drop.
• Fix: none needed if the load voltage is correct. If the drop exceeds 0.3V, the sense function has reached its compensation limit and the cable has to be resized.

The screen behaves erratically and the sense wiring is long

• Possible cause: untwisted or poorly routed sense lines picking up noise. The datasheet specifies the +S and −S leads be twisted in a pair for exactly this reason.
• How to check: inspect the routing of the CN100 sense pair. If it runs alongside high-current output cables without being twisted, that is the likely source.
• Fix: twist the sense pair, keep it away from the output conductors, and re-terminate. This is a low-cost fix that is frequently overlooked.

Output drops out and recovers on its own, repeatedly

• Possible cause: over-temperature protection. Note that this is not the overload behaviour on this model — overload limits current rather than switching off, so a supply that switches off and back on is responding to temperature, not current.
• How to check: measure cabinet ambient and case temperature, and confirm the fan is actually turning. At 5V the fan should run continuously.
• Fix: restore airflow. If the fan has failed, the supply has no reserve — the rating depends on forced airflow and the fan is a wear item on a decade-long installation.

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

• Possible cause: nothing is faulty. Set-up is 1500ms at 230VAC and 3000ms at 115VAC, with an 80ms rise time — slightly slower than the 50ms rise on the models below.
• 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 specification. If control logic assumes supplies are ready sooner, adjust the sequence timing rather than replacing hardware.

Mean Well RSP-500-5: Frequently Asked Questions