Mean Well UHP Series · Ultra-Thin 31 mm · Fanless · 9 Rails 3.3–55 V · Active PFC
Mean Well UHP-350 Switching Power Supply
The Mean Well UHP-350 switching power supply pushes 350 W through a 31 mm fanless aluminum profile — nine rails from 3.3 V to 55 V (the 5 V model carries 60 A), a 90–264 VAC universal input with active PFC, 300 VAC surge tolerance for 5 seconds, and an R type that parallels two units for automatic redundancy.
📱 / WhatsApp: +86-191-18802497 · Shenzhen, China · GMT+8
300 W
Rated output (5 V / 60 A)
31 mm
Fanless slim profile
3.3–55 V
Nine rails, 60 A top
300 VAC
Surge input, 5 seconds
1.79M h
MTBF (Telcordia SR-332)
Short answer
The Mean Well UHP-350 is a 350 W single-output slim-type AC/DC switching power supply with a 31 mm fanless aluminum profile, a 90–264 VAC universal input with built-in active PFC, and nine rails from 3.3 V to 55 V — the screen-relevant 5 V model carries 60 A / 300 W. It withstands 300 VAC surge input for 5 seconds, rides out 5 G vibration, passes EN 61000-6-2 heavy-industry immunity, and the R type adds an optocoupled DC OK signal plus two-unit redundant parallel operation. With the factory-specified 450 mm aluminum plate it holds full load to 50°C on air convection alone — and its 1,791,200-hour Telcordia MTBF rating is the highest we publish on any supply page.
What Is the Mean Well UHP-350 Switching Power Supply?
The Mean Well UHP-350 is a 350 W single-output enclosed AC/DC switching power supply (SMPS) built on a 31 mm low-profile aluminum chassis cooled entirely by air convection — no fan, no filter, no dust path. The series spans nine rails from 3.3 V to 55 V; the screen-relevant 5 V model delivers 60 A, and the 55 V model is the factory’s Power Source Equipment pick for PoE. MEAN WELL lists LED display application among the series’ own use cases, alongside industrial control and household appliances.
Inside the chassis, the protection chain runs exactly as the factory block diagram draws it — EMI filter into the PFC front end, the switching stage, then rectification with detection, OVP and OTP supervision, and the DC OK / redundant-function block hanging off the control stage on R-type units:
Within the Mean Well screen set, the UHP-350 is the heavy half of the slim line: it takes the UHP-200’s 26 mm recipe, adds 5 mm of profile and 75% more power, and lands on the same 5 V / 60 A / 300 W output as the fan-cooled RSP-320 — with a 300 VAC / 5-second surge window, 5 G vibration tolerance, EN 61000-6-2 heavy-industry immunity and a dual-method MTBF of 1,791,200 hours minimum (Telcordia SR-332) plus 253,400 hours minimum (MIL-HDBK-217F, 25°C). The 220 × 62 × 31 mm case weighs 0.68 kg and carries UL 62368-1, TUV, EN 60335-1 (household appliances, except 55 V), BIS and CCC approvals with a 3-year warranty.
240 W on the 5 V rail
A 48 A budget at the 80% rule — a dense slim bay in 31 mm of profile, with no fan to fail or filter to service.
1.79M h MTBF
The highest Telcordia figure on our power pages, dual-signed with MIL-HDBK-217F — tender paper writes itself.
R type redundancy
The UHP-350R parallels two units — one fails, the other takes over automatically and the screen stays lit.
Planning a screen’s full electrical side? Pair this page with the LED display power consumption guide, and for the control end of the same cabinet see the LED screen display control system catalog. For a slim screen in the metal, here is the profile our own ultra-thin indoor series achieves on the same conduction-mount logic:
What Are the Mean Well UHP-350 Switching Power Supply Specifications?
Every figure below comes from the official Mean Well UHP-350 specification sheet (6 pages, revision dated 2024-11-23). The nine-rail table first, then the platform parameters:
| Model | Rail / current | Rated power | Adj. range | Tolerance | Ripple (max.) | Efficiency |
|---|---|---|---|---|---|---|
| UHP-350-3.3 | 3.3 V / 60 A | 198 W | 3.2–3.5 V | ±2.0% | 150 mVp-p | 88.5% |
| UHP-350-4.2 | 4.2 V / 60 A | 252 W | 3.6–4.4 V | ±2.0% | 150 mVp-p | 89% |
| UHP-350-5 | 5 V / 60 A | 300 W | 4.5–5.5 V | ±2.0% | 200 mVp-p | 90% |
| UHP-350-12 | 12 V / 29.2 A | 350.4 W | 11.4–12.6 V | ±1.0% | 200 mVp-p | 91% |
| UHP-350-15 | 15 V / 23.4 A | 351 W | 14.3–15.8 V | ±1.0% | 200 mVp-p | 92% |
| UHP-350-24 | 24 V / 14.6 A | 350.4 W | 22.8–25.2 V | ±1.0% | 240 mVp-p | 94% |
| UHP-350-36 | 36 V / 9.75 A | 351 W | 34.2–37.8 V | ±1.0% | 240 mVp-p | 94% |
| UHP-350-48 | 48 V / 7.3 A | 350.4 W | 45.6–50.4 V | ±1.0% | 240 mVp-p | 94% |
| UHP-350-55 | 55 V / 6.3 A | 350 W | 45–58 V | ±1.0% | 300 mVp-p | 94% |
| Common to all nine rails | Value |
|---|---|
| Input voltage range | 90–264 VAC / 127–370 VDC, 47–63 Hz (nameplate: 100–240 V, 4 A) |
| Surge input tolerance | Withstands 300 VAC surge input for 5 seconds |
| Power factor | Active PFC: PF ≥ 0.94 at 230 VAC; PF ≥ 0.98 at 115 VAC, full load |
| Line / load regulation | ±0.5% line (3.3–5 V), ±0.3% (12 V+); ±1.0% load (3.3–5 V), ±0.5% (12 V+) |
| Setup / hold-up time | 2000 ms, 80 ms at 230 VAC; 3000 ms, 80 ms at 115 VAC (550 ms setup for the 55 V model); hold-up 10 ms |
| AC current / inrush | 4 A at 115 VAC, 2 A at 230 VAC / cold start 30 A at 115 VAC, 60 A at 230 VAC (±10%) |
| Leakage current | <0.75 mA at 240 VAC |
| Protections | Overload 110–140%: hiccup mode, auto-recovery; OVP: shut down, re-power on to recover; OTP: shut down, auto-recovery; short circuit |
| R-type functions | DC OK optocoupler signal (contact rating 15 Vdc / 10 mA resistive); redundant operation: two units in parallel, automatic takeover, load ≤ one unit’s rated power |
| Vibration | 10–500 Hz, 5 G, 10 min per cycle, 60 min each along X, Y, Z axes |
| Working temperature | −30°C to +70°C by air convection, fanless (full load to 50°C with the aluminum plate); 20–95% RH; 3.5°C per 1000 m above 2000 m altitude, rated to 5000 m |
| MTBF | 1,791.2K hrs min. (Telcordia SR-332); 253.4K hrs min. (MIL-HDBK-217F, 25°C) |
| Dimensions / packing | 220 × 62 × 31 mm (Case 232C) / 0.68 kg, 16 pcs per carton |
| Safety / EMC | UL 62368-1, TUV BS EN/EN 62368-1, BS EN/EN 60335-1 (except 55 V), BS EN/EN 61558-1/-2-16, GB 4943.1, BSMI CNS 15598-1, EAC TP TC 004, BIS IS 13252 (except 4.2/15/48/55 V), RCM (voluntary); BS EN/EN 55032 / GB 9254.1 Class B, EN 55014, EN 61000-3-2/-3; immunity to EN 61000-4 suite, EN 61000-6-2 heavy-industry level, EN 55035 |
| Warranty | 3 years |
Factory mechanical drawing: 220 × 62 × 31 mm, Case 232C, TB1 and TB2/TB3 marked
Field notes before you buy
First, input range: the datasheet specifies 90–264 VAC while the production nameplate reads 100–240 V, 4 A (the 24 V model photographed below, built at MEAN WELL’s Shenzhen plant) — the factory curve gives full rated load from 110 VAC upward and roughly 75% at the 90 VAC floor. Second, the profile grew 5 mm and the aluminum plate grew 50% against the UHP-200 — 450 mm square — because 350 W through a fanless base needs the spread. Third, overload is hiccup mode: the output pulses off and on while the fault persists, then recovers by itself. Fourth, the R type’s efficiency runs slightly below the blank type per the datasheet’s own note.
Production nameplate: INPUT 100–240 VAC, 4 A · OUTPUT +24 V, 14.6 A · MEAN WELL (Shenzhen) build
Which LED Display Loads Fit the Mean Well UHP-350 5 V Rail?
Apply the industry-standard 80% loading rule and the UHP-350-5 gives you a dense-slim-bay budget: 60 A × 80% = 48 A usable, 300 W × 80% = 240 W usable per unit.
Mapped onto typical loads (average draws under normal program material — full-white patterns run higher, so verify against your module datasheet):
| Typical load | Rail | Average draw | Per UHP-350 at 80% |
|---|---|---|---|
| Indoor P2.5 module (320 × 160 mm) | 5 V | ~10–15 W | ~16–24 modules |
| Dense slim bays (poster and thin-bezel cabinets) | 5 V | Per bay design | One unit per 240 W bay |
| 12 V signage and strip runs | 12 V | ~5–10 W per meter | ~24–48 m (29.2 A rail) |
| 24 V cooling and control banks | 24 V | ~5–10 W per fan | Inside the 240 W budget |
| PoE midspan / PSE feed | 55 V | Per PD budget | 350 W rail cap |
At the 90 VAC floor the factory static curve derates the unit to roughly 75% — re-run the budget if the site sits on a weak grid. For bigger 5 V bays the step up is the Mean Well RSP-500 (90 A / 450 W) or the LRS-600 (100 A / 500 W), with the per-cabinet count logic in how many power supplies an LED screen needs.
Why Does the Mean Well UHP-350 Need a 450 mm Aluminum Plate?
A 31 mm fanless chassis has exactly one heat path: conduction into whatever it sits on. The factory installation sheet is explicit — to meet the published derating curve, the UHP-350 must be installed onto an aluminum plate (or a cabinet plate of the same size) mounted under the unit:
Plate size and fixing
The suggested plate is 450 × 450 mm, 3 mm thick, fixed with four M3×4 screws — half again larger than the 300 mm plate the 200 W UHP asks for, because 350 W through a fanless base needs the spread.
Surface condition
The plate face under the unit must be even and smooth, or coated with thermal grease — an uneven or anodized-only face adds degrees you have no fan to remove.
Position
The unit mounts firmly at the center of the plate — offset mounting strands the edges of the plate and shrinks the effective heat path.
The derating curves put numbers on it. With the plate, the unit holds full load to 50°C and roughly 60% at 70°C. Without the plate, the factory publishes a separate curve that turns on at just 45°C and sags to roughly 40% by 70°C — with the 55 V model falling off earliest and 110 VAC grids sitting a tier lower still. In a closed cabinet at 60°C, skipping a 3 mm plate costs you close to half the supply.
What Do the R Type’s DC OK and Redundant Functions Add to the Mean Well UHP-350?
The base UHP-350 is a plain enclosed supply. Order it with the R suffix and two functions come built in — both aimed at screens that must not go dark:
DC OK signal (optocoupled)
An optocoupler contact reports the output state, galvanically separate from the rail: C–E conduction means the PSU is on (DC OK), an open contact means DC fail. Contact rating 15 Vdc / 10 mA resistive, wired on the CN10 header (DC COM / DC OK +V, JST PHR-2 housing) to a controller fault input.
Redundant parallel (2 units)
The R type’s built-in redundancy logic lets two units share one bus: when one PSU cannot work, the other is enabled automatically and the load keeps running. Size the bus at or below one unit’s rated power — the second unit exists for takeover, not extra capacity.
Where it sits in the parallel map
Two-unit auto-takeover here; four-unit active sharing (3+1) on the Mean Well RSP-1000; and no paralleling at all on the rest of the RSP ladder. Pick by how much bus you actually need to protect.
How Does the Mean Well UHP-350 Survive Harsh Grids and Vibrations?
Three datasheet lines separate this slim supply from the usual indoor-rated crowd:
300 VAC surge, 5 seconds
The input tolerates 300 VAC for five seconds — generator step events, unstable industrial feeds, a mis-selected transformer tap. It is a survival window, not an operating range: continuous input still tops out at 264 VAC.
Heavy-industry immunity
EN 61000-6-2 immunity at heavy-industry level across the EN 61000-4 suite, plus EN 55035 — ESD, radiated and conducted RF, fast transients, surge, dips. Industrial-floor EMC without an external filter.
5 G vibration
Swept at 10–500 Hz, 5 G, one hour per axis — truck-parked screens, moving rigs and factory-floor mounts stop being a disqualifier.
The grid table, per the factory static-characteristics curve (full load from 110 VAC upward):
| Grid | Verdict on the UHP-350 |
|---|---|
| 220–240 V (EU, UK, Middle East, Asia, AU) | Full rated load; the nameplate’s design center (100–240 V) |
| 110–120 V (US, Canada, Japan, Taiwan) | Full rated load at 4 A AC input — no transformer caveat |
| 90–100 V (brownout-prone grids) | Runs at roughly 75% of rated per the factory curve — re-run the load budget |
One environment note: rated to 5000 m altitude, and because the whole series is fanless the high-altitude derate is just 3.5°C per 1000 m above 2000 m. The appliance-side safety mark (EN 60335-1, except the 55 V model) is why this series also lives inside household and commercial LED appliances.
Mean Well UHP-350-5 vs RSP-320-5: Which 300 W Supply Wins?
These two carry the identical 5 V / 60 A / 300 W output from two different engineering lines — and both already have full pages on this site:
| Parameter | Mean Well UHP-350-5 | Mean Well RSP-320-5 |
|---|---|---|
| Output | 5 V / 60 A / 300 W | 5 V / 60 A / 300 W |
| Profile | 220 × 62 × 31 mm slim aluminum profile, 0.68 kg, fanless | 1U enclosed chassis with a speed-controlled fan |
| Rails | Nine, 3.3 V to 55 V | Twelve, down to 2.5 V |
| Surge headroom | 300 VAC input for 5 seconds | Not a published feature |
| Redundant option | UHP-350R: two units, auto-takeover | None — do not parallel |
| Appliance safety | BS EN/EN 60335-1 approved (except 55 V) | Not part of the approval set |
| MTBF | 1,791.2K h Telcordia + 253.4K h MIL (dual-method) | Dual-method, lower Telcordia figure |
| Warranty | 3 years | 3 years |
The choice is mechanical before it is electrical. Need the supply to disappear into a slim bay, ride out a truck or a factory floor, fail over automatically, or post the highest MTBF figure in the tender? The UHP-350 is the only line here that answers all four. Need the deepest rail menu or a lower-voltage rail for special modules? The RSP-320’s twelve rails go where the UHP does not. Full detail on the fan-cooled sibling lives on the Mean Well RSP-320 switching power supply page.
Where Does the Mean Well UHP-350 Fit the Mean Well Ladder?
The screen-relevant Mean Well set now covers every geometry a cabinet can ask for:
RSP-150 · 5 V 30 A
120 W budget, fanless, the single-bay entry.
RSP-200 · 5 V 40 A
160 W budget, fanless 1U, twelve rails.
RSP-320 · 5 V 60 A
240 W budget, speed-controlled fan.
RSP-500 · 5 V 90 A
360 W budget with remote sense.
RSP-1000 · 12 V 60 A
Kilowatt platform, parallel to 4000 W.
UHP-350 · 5 V 60 A
The 31 mm slim position: fanless, 300 VAC surge, R-type redundancy, 1.79M h MTBF.
The slim line has its own ladder below: the UHP-200 carries the same recipe at 200 W in 26 mm with a 300 mm plate — step up to this 350 W unit when the bay grows. And the economy line runs its own ladder — the LRS-600 at 100 A / 500 W with the fanless NEL-400 as the slim 80 A alternative.
How Do You Install and Wire the Mean Well UHP-350 Safely?
One AC block, two DC blocks and one signal header define the wiring workflow:
| Block / pin | Assignment |
|---|---|
| TB1 · 1 / 2 / 3 | AC/L · AC/N · FG (frame ground) — 5 Kgf-cm max |
| TB2 / TB3 · 1,2 / 3,4 | DC output −V / +V — 8 Kgf-cm max |
| CN10 · 1 / 2 | DC COM · DC OK +V (R type, JST PHR-2 housing) |
1 · Mount on the aluminum plate
450 × 450 mm, 3 mm thick (or a cabinet plate of the same size), face smooth or greased, unit centered, four M3×4 screws. This step is what makes the derating curve true.
2 · Wire AC, DC and ground
Mains into TB1 (5 Kgf-cm), the module bus across TB2/TB3 (8 Kgf-cm), FG bonded to cabinet earth. Check polarity with a meter before the first power-up.
3 · Optional: DC OK wiring
On the R type, run the CN10 pair to a controller fault input (15 Vdc / 10 mA contact class) so the cabinet reports a dead rail before operators see one.
4 · Set the rail with +V ADJ
Trim at the load end under full load — the 5 V model adjusts 4.5–5.5 V, the 12 V model 11.4–12.6 V — then confirm each bay measures the same within a few tenths.
5 · Load-test
Run a full-white pattern for ten minutes, check the power LED stays lit, feel the plate for hot spots, then re-torque before closing the bay. Our ultra-light panels go up without a lift crew:
Two rules to respect
The aluminum plate is a requirement, not an accessory — without it the derating curve turns on at 45°C and cuts the unit toward 40% load in a hot cabinet. And after an over-voltage trip the output latches off until the AC feed is cycled: find the upstream cause before restarting the screen.
When a unit does fail in the field, our LED display power supply diagnostics and replacement guide walks the test-and-swap workflow end to end.
What Problems Does a Failing Mean Well UHP-350 Power Supply Cause?
Power trouble wears disguises — check these three signatures before blaming a module or a control card:
Output pulses on and off
Hiccup mode is the overload signature: the unit pulses while the load exceeds 110–140%. Re-check the 80% budget before swapping parts; a latched OVP instead means a dead output until re-power.
Slim bay, weak rail in the heat
A UHP-350 on a thin standoff or painted plate derates from 45°C onward. If the bay browns out only on summer afternoons, the plate — not the supply — is the first suspect.
Flicker on camera or under load spikes
An overloaded rail dips for a frame at a time. Flicker that tracks bright content points at the supply first — re-run the 240 W budget before touching the modules.
How Much Does the Mean Well UHP-350 Cost?
The slim platform prices above the same-wattage fan-cooled classics: expect the single-unit authorized-distributor price to sit above the RSP-320’s class, with the exact figure moving by rail and by market — the mechanical premium buys the 31 mm profile, the surge window, the R-type option and the highest MTBF signature in the set. Mean Well packs this series 16 pieces to a carton, and volume pricing for production quantities steps down from list.
Sample · 1–10 pcs
For repairs, prototypes and trial bays — shipped from stock with the nameplate you see above.
Project · 10–500 pcs
Whole-screen and fleet quantities with per-bay load math and the 450 mm plate mount designed into the cabinet.
Volume · 500+ pcs
Production-line pricing with container freight planning and batch date-code consistency.
Send the module types, modules-per-bay and total cabinet count, and the quote comes back with the load math attached — from an LED screen manufacturer that stocks the full chain from power to control.
Mean Well UHP-350 Switching Power Supply: Frequently Asked Questions
Can the UHP-350 run on a 110 V outlet in the US?
Yes. The 90–264 VAC universal input carries full rated load from 110 VAC upward (4 A AC input at 115 VAC); only the 90–100 V band asks for the roughly 25% derating the factory static curve shows. No step-up transformer is needed for US, Canadian or Japanese grids.
How many LED modules can one UHP-350-5 drive?
At the 80% loading rule: 240 W or 48 A usable on the 5 V rail. A typical indoor P2.5 module draws about 10–15 W of average program material, so one unit covers roughly 16–24 such modules — verify against your module datasheet and brightness profile.
What happens if I skip the 450 mm aluminum plate?
The unit runs, but it no longer meets the published derating curve: the factory without-plate curve turns on at just 45°C and sags to roughly 40% load by 70°C, with the 55 V model falling off earliest. The plate is a 450 × 450 mm, 3 mm aluminum sheet under the unit, smooth or greased, mounted centered with four M3×4 screws — or a cabinet wall of the same size doing the same job.
Can I parallel two UHP-350 units for redundancy?
Only the R type: the UHP-350R’s built-in redundancy function connects two units on one bus, and when one cannot work the other is enabled automatically. Keep the bus load at or below one unit’s rated power — the pair is for takeover, not extra capacity. The blank type has no sharing feature; for bigger protected buses, the RSP-1000 parallels four units (3+1).
What does the DC OK signal do on the R type?
DC OK is an optocoupler contact, galvanically separate from the output: C–E conduction means the PSU is on, an open contact means DC fail. The contact handles up to 15 Vdc / 10 mA resistive and lives on the CN10 header (DC COM / DC OK +V, JST PHR-2 housing) — wire it to a PLC or controller fault input for cabinet-level monitoring.
What does “withstands 300 VAC surge input for 5 seconds” mean in practice?
Five-second surges up to 300 VAC — generator step events, unstable industrial feeds, a wrong transformer tap — pass through without damaging the unit, where ordinary 264 V-max supplies can fail. It is a survival window, not an operating range: continuous input still tops out at 264 VAC.
What warranty and service life does Mean Well publish?
A 3-year warranty with a dual-method MTBF: 1,791,200 hours minimum by Telcordia SR-332 plus 253,400 hours minimum by MIL-HDBK-217F at 25°C — the highest Telcordia figure on our power pages. Note the datasheet’s own line that the R type’s efficiency runs slightly below the blank type’s.
What is the 55 V model for?
The factory positions the UHP-350-55 (55 V / 6.3 A / 350 W) as Power Source Equipment for PoE — powering network-fed builds — and the wide 45–58 V adjustment also suits long-run distribution. It is the only rail on the series with a separate 550 ms setup-time note and the only one excluded from the EN 60335-1 appliance approval.
Quote the Mean Well UHP-350 With the Load Math Done
Send your module types and cabinet count; we return per-bay power sizing and a matched quote from a LED screen manufacturer that ships worldwide.
📱 / WhatsApp: +86-191-18802497 · Shenzhen, China · GMT+8
More Mean Well Switching Power Supply and LED Display Power Resources
LED Display Power Supply (Mother Catalog)
The three-brand mother catalog: 27 model pages, 2026 price bands, architecture map and the 80% load math — start here.
Mean Well UHP-500 (5 V 80 A)
The slim flagship above: 400 W on the rail, up to 95% efficiency, relay DC OK and R-type redundancy.
Mean Well UHP-200 (5 V 40 A)
The slim sibling: the same recipe at 200 W in 26 mm with a 300 mm plate.
Mean Well RSP-320 (5 V 60 A)
The same 300 W from the fan-cooled 1U line: twelve rails down to 2.5 V.
Mean Well RSP-1000 (12 V 60 A)
The kilowatt platform: parallel to 4000 W (3+1) with a 5-year warranty.
Mean Well LRS-600 (500 W)
The economy ladder top: 5 V / 100 A / 500 W across seven rails.
Mean Well NEL-400 (400 W)
The slim 80 A alternative: 30 mm chassis with conformal coating standard.
LED Display Power Consumption
Screen-level power math: module draw, brightness settings, breaker sizing and cable gauges.
Power Supply Diagnostics & Replacement
Test a suspect supply, swap it inside a live screen, and root-cause repeat failures.