MEAN WELL RSD-30G-24 is an enclosed, isolated railway DC/DC converter delivering 24 V at up to 1.25 A, with a rated output of 30 W. This G-input model accepts 9–36 VDC continuously. Its 25 mm metal enclosure, semi-potted silicone construction and fanless cooling suit railway, transport, telecom and industrial equipment, subject to the specified input, thermal and installation conditions.
Product Datasheet
Download MEAN WELL RSD-30 Datasheet (PDF)
The RSD-30 section is on PDF pages 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. Refer to the complete mechanical drawings and notes when planning installation.
Model and DC Output
| Full model |
RSD-30G-24 |
| Series |
RSD-30 |
| Input code |
G |
| DC output voltage |
24 V |
| Rated output current |
1.25 A |
| Rated output power |
30 W |
| Output current range |
0–1.25 A; no minimum load required |
| Maximum ripple and noise |
50 mVp-p |
| Voltage tolerance |
±2.0% |
| Line regulation |
±0.2% |
| Load regulation |
±0.2% |
| Set-up / rise time at full load |
120 ms / 85 ms |
The electrical values above apply to RSD-30G-24. Voltage tolerance includes set-up tolerance, line regulation and load regulation. Except where stated otherwise, the catalogue measurements use 24 VDC input, rated load and 25°C ambient temperature.
Ripple and noise are measured with 20 MHz bandwidth and a 12-inch twisted-pair connection terminated with 0.1 µF and 47 µF capacitors in parallel. The manufacturer strongly recommends limiting external output capacitance to 5000 µF or less.
Input, Startup and Interruption Behaviour
| Continuous DC input range |
9–36 VDC |
| Input-range ratio |
4:1 |
| Typical efficiency |
89% |
| Typical DC input current |
1.5 A at 24 VDC |
| Typical input inrush current |
20 A at 24 VDC |
| Short-duration input-transient capability |
±40% of rated input voltage for 1 second |
| Supply-interruption reference |
EN 50155:2021, S1 level |
| Nominal switching frequency |
110 kHz |
| Internal input fuse reference |
CONQUE MST, time-lag, 6.3 A, 250 V |
Select the input version by its continuous DC range. The separate 1-second transient statement is a short-duration withstand condition; continuous operation remains within the specified input range.
The fuse is in series with the positive input. A resistor limits inrush during startup and is then bypassed by a MOSFET to reduce power consumption. The fuse reference identifies an internal component and its rating.
The model-specific hold-up curve indicates approximately 10 ms at 80% load. Hold-up time varies with load; use the RSD-30G-24 curve when selecting the interruption load. This graph point is not a full-load hold-up guarantee.
Protection and Status Indication
| Short-circuit / overload function |
Built-in constant-current limiting; automatic recovery after the fault is removed |
| Overload detection range |
105–135% of rated output power |
| Overvoltage protection threshold |
27.6–32.4 V |
| Overvoltage recovery |
Output shutdown; reapply input power to recover |
| Input reverse-polarity protection |
A series MOSFET in the negative input opens under reversed polarity; no output |
| Input undervoltage protection |
Internal control shuts down below its threshold; output recovers automatically when input rises above the recovery threshold |
| Power indicator |
Green LED: normal operation; no indication: no input power or failure |
| Illustrated undervoltage thresholds for this 24 V model |
Turn on: 8.3 VDC; turn off: 6.3 VDC |
Constant-current protection is a fault response, not an additional continuous rating. Continuous overload operation can cause excessive temperature, reduced life or damage.
The turn-on and turn-off points are the model-labelled graph values. They do not replace the specified continuous input range.
Operating Environment and Load Derating
| Operating ambient range |
−40 to +70°C, subject to input and thermal conditions |
| Free-air full-load upper ambient limit |
55°C |
| Free-air load limit at 70°C |
60% |
| Full load at 70°C with added base plate |
Permitted with the specified external iron-plate mounting arrangement |
| Low-temperature input condition |
In the −40 to −35°C shaded region, input must be at least 24 VDC |
| Case-temperature graph limit |
75°C at the indicated tc position |
| Operating humidity |
5–95% RH, non-condensing |
| Storage temperature |
−40 to +85°C |
| Temperature coefficient |
±0.03%/°C over 0–50°C |
| Operating altitude |
Up to 5000 m, with the high-altitude temperature derating below |
| Vibration rating |
10–500 Hz, 5 G; 10 minutes per cycle, 60 minutes on each X, Y and Z axis; mounting to IEC 61373 |
Without an added iron plate, the ambient-temperature curve shows full load through 55°C, followed by derating to 60% at 70°C. Use the more restrictive input-voltage and temperature limits together.
For this fanless converter, reduce the allowable ambient temperature by 3.5°C per 1000 m above 2000 m. The operating-altitude limit remains 5000 m.
The separate case-temperature plot ends at 75°C. Monitor the tc point identified in the mechanical drawing; a case-temperature limit is not an ambient-temperature rating.
Mechanical Installation and Terminal Connections
| Dimensions, L × W × H |
113 × 60 × 25 mm |
| Mechanical drawing |
Case No. 253A; dimensions in mm, general tolerance ±1 mm |
| Unit mass |
250 g; catalogue PACKING reference per unit |
| Enclosure and cooling |
Enclosed metal case, 25 mm low profile; semi-potted silicone interior; free-air convection |
| Mounting holes |
Four Ø3.5 mm holes on a 105 × 52 mm pattern |
| Input terminal 1 |
DC INPUT V+ |
| Input terminal 2 |
DC INPUT V− |
| Input terminal 3 |
FG / chassis ground |
| Output terminal 1 |
DC OUTPUT −V |
| Output terminal 2 |
DC OUTPUT +V |
| tc drawing location |
46 mm from the right end and 7 mm above the base in the side view |
| External cooling plate shown |
360 × 360 × 2 mm iron plate; M3 × 4 screws illustrated |
Follow the numbered input and output terminal assignments in the RSD-30 mechanical drawing. The input and output blocks have separate numbering; connect FG to the designated chassis-ground terminal.
For full-load operation at 70°C under the EN 50155 TX installation condition, mount the converter firmly at the centre of the specified iron plate. The mating surface must be flat and smooth for effective heat transfer. The plate is an added thermal component; this mounting condition does not describe a plate supplied as standard.
The catalogue illustrates several horizontal and vertical enclosure orientations, both with and without the added plate, and states that the illustrated methods share the applicable derating curve because the unit is semi-potted. Maintain free-air convection and verify the completed mounting arrangement.
Options, Redundancy and Series Connection
| Output-voltage adjustment |
Optional by manufacturer arrangement; absent from the standard product |
| Internal current-sharing circuit |
Not fitted |
| Parallel use described |
External diode-assisted redundancy only; output current rating is not increased |
| Redundancy diode requirement |
One diode at each positive output; diode current rating greater than the converter maximum output current, with a suitable heat sink |
| Series use described |
Bipolar outputs or summed output voltage; the available current does not increase |
| Series blocking-diode requirement |
External diodes as shown in the catalogue; voltage rating greater than the total V1 + V2 |
For optional output adjustment, contact MEAN WELL for the applicable supply arrangement before ordering. The catalogue does not identify a separate adjustment-option ordering suffix.
Redundant parallel operation requires an external circuit suitable for the system. Parallel connection increases leakage current; consult the supplier and verify the complete installation.
The unit does not contain the reverse-blocking diodes needed for the illustrated series arrangement. Use the external-diode topology in the catalogue to protect each converter during startup. Series connection can form positive and negative rails around a common point or add output voltages.
The series pages do not identify separately orderable MEAN WELL cable, terminal-housing, diode-kit or cooling-plate model numbers. Select external components by the stated electrical and mechanical requirements; the catalogue case and fuse references are component information.
Safety, EMC and Reliability
| Catalogue approved safety standards |
IEC 62368-1; UL 62368-1; AS/NZS 62368-1; EAC TP TC 004 |
| Catalogue safety design reference |
BS EN/EN 62368-1 |
| Railway standards listed |
BS EN/EN 50155 / IEC 60571; IEC 61373 for shock and vibration; BS EN/EN 50121-3-2 for EMC; BS EN/EN 45545-2 for fire protection |
| Input-to-output withstand voltage |
4 kVDC; reinforced isolation |
| Input-to-FG withstand voltage |
2.5 kVDC |
| Output-to-FG withstand voltage |
2.5 kVDC |
| Insulation resistance |
100 MΩ at 500 VDC, 25°C and 70% RH; input–output, input–FG and output–FG |
| Conducted emissions |
BS EN/EN 55032, Class A |
| Radiated emissions |
BS EN/EN 55032, Class B |
| EMC immunity reference |
BS EN/EN 55035 |
| ESD immunity |
BS EN/EN 61000-4-2; Level 3, ±8 kV air and ±6 kV contact |
| Radiated-field immunity |
BS EN/EN 61000-4-3; Level X, 20 V/m |
| EFT / burst immunity |
BS EN/EN 61000-4-4; Level 3, 2 kV on power |
| Surge immunity |
BS EN/EN 61000-4-5; Level 3, 1 kV line–line and 2 kV line–earth |
| Conducted immunity |
BS EN/EN 61000-4-6; Level 3 |
| MTBF, Telcordia SR-332 |
3093.5 thousand hours minimum |
| MTBF, MIL-HDBK-217F |
396.9 thousand hours minimum at 25°C |
| Catalogue warranty period |
3 years; subject to manufacturer terms |
The converter is a component for integration into end equipment. Catalogue approvals and design references describe the converter and do not constitute certification of the completed railway vehicle or other end system.
The EMC test fixture uses a 360 × 360 × 1 mm metal plate. This EMC fixture is distinct from the 2 mm iron plate specified for full-load operation at 70°C. EMC compliance must be reconfirmed for the completed installation.
MTBF values are reliability calculations under the stated method and conditions, not a guaranteed operating lifetime.
Catalogue Environmental and Fire Tests
| Dry heat test, EN 50155 §13.4.5 |
PASS; 70°C for 6 hours and 85°C for 10 minutes |
| Cyclic damp heat test, EN 50155 §13.4.8 |
PASS; 25–55°C, 90–100% RH, 48 hours |
| Vibration environmental test, EN 50155 §13.4.10 |
PASS; 19°C, 65% RH, 10 minutes |
| Shock environmental test, EN 50155 §13.4.10 |
PASS; 21 ±3°C, 65 ±5% RH, 30 ms × 18 |
| Low-temperature storage test, EN 50155 §13.4.6 |
PASS; −40°C, 16 hours |
| Salt-mist test, EN 50155 §13.4.13 |
PASS; 35 ±2°C, 96 hours |
| PCB fire tests |
EN 45545-2:2020: R22 oxygen index, smoke density and smoke toxicity; R24 oxygen index; R25 glow-wire test. HL1, HL2 and HL3: PASS for each listed test. |
| Potting material fire test |
EN 45545-2:2020 R24 oxygen-index test; HL1, HL2 and HL3: PASS |
| Terminal-block fire test |
EN 45545-2:2020 R26 vertical-flame test; HL1, HL2 and HL3: PASS |
The following are the catalogue environmental and material-test results, with their specific test exposures. They do not extend the continuous operating temperature, humidity or mounting limits.
The fire-test table covers the specified PCB, potting material and terminal block. Its supporting methods include EN ISO 4589-2:2017, EN ISO 5659-2:2017, EN 17084:2018, EN 60695-2-11:2014 and EN 60695-11-10:2013 as applicable to the listed material and test.
