Mean Well SDR-120-24 DIN Rail Power Supply

Name: Mean Well SDR-120-24 DIN Rail Power Supply – Datasheet
Brand: Mean Well
SKU: SDR-120-24

120 W DIN rail supply with PFC and 150% peak power

The Mean Well SDR-120-24 is a 120 W single-output DIN rail power supply with a built-in power factor correction function and a 24 V DC output at 5 A. Unlike the economical NDR-120 and EDR-120 series, the SDR-120 adds a peak rating: it can deliver 7.5 A (180 W) for up to 3 seconds, which helps with motor starters, relays that pull in together and capacitive loads.

Typical efficiency at 24 V is 91% and the power factor is 0.93 at 230 VAC and 0.96 at 115 VAC at full load. The input range is 88 to 264 VAC (124 to 370 VDC). A DC OK relay contact is built in, the operating range is -25 to +70 C, and the 40 mm housing is cooled by free air convection.

Technical specifications

Parameter	Specification
Manufacturer / series	Mean Well, SDR-120
Model	SDR-120-24
DC output	24 V DC / 5 A
Power rating	120 W
Peak current / peak power	7.5 A / 180 W for 3 seconds
Trim range	24 to 28 V
Ripple (max.)	100 mVp-p
Setpoint tolerance	+/-1.0%
Mains input	88 to 264 VAC; 124 to 370 VDC
Power factor (typ.)	0.93 at 230 VAC; 0.96 at 115 VAC, full load
Typical efficiency	91%
Input current (typ.)	1.4 A at 115 VAC; 0.7 A at 230 VAC
Inrush (typ.)	35 A at 115 VAC; 70 A at 230 VAC
Hold-up (typ.)	20 ms at 230 VAC and 115 VAC
Overload behaviour	110 to 150% for over 3 s then shut down; above 150% current limiting, shut down after 3 s
Overvoltage limit	29 to 33 V, shut down; re-power to recover
DC OK relay contact	60 Vdc/0.3 A, 30 Vdc/1 A, 30 Vac/0.5 A resistive
Ambient operating range	-25 to +70 C, with derating curve
Approvals named	UL 508, TUV EN 62368-1, EAC TP TC 004, BSMI; SEMI F47
Size (W x H x D)	40 x 125.2 x 113.5 mm
Mass	0.67 kg

Peak power and how the overload behaviour works

The SDR-120 does not hold a constant-current limit indefinitely. According to the datasheet, between 110 and 150% of rated power it keeps running for more than 3 seconds before shutting down the output, and above 150% it limits current and shuts down after 3 seconds. That makes it suited to loads with short inrush peaks, and it also means a sustained overload will latch the unit off until power is cycled, so do not size the supply on the peak rating.

When PFC helps in a panel

A power factor near 0.93 to 0.96 reduces reactive current drawn from the feeder, which matters when many supplies share one breaker or a generator. Check the inrush current of 35 A at 115 VAC and 70 A at 230 VAC against the upstream breaker curve. The built-in DC OK relay can report a failing supply to the PLC. Fit it on TS-35/7.5 or TS-35/15 rail with the clearances given in the datasheet. Verify with a clamp meter that the real start-up current of the connected loads stays inside the peak window before you rely on it.

Documents and quotation

Before you finalise the selection, read the attached SDR-120 specification for derating and wiring information. A request for SDR-120-24 should state quantity, supply conditions, load current with peaks, operating temperature and required certificates, so that the right variant is confirmed. Alternatives are listed in Power Modules.

Mean Well power supply families

The catalogue covers DIN rail power supplies from 15 W to several hundred watts in single-phase and three-phase versions, enclosed chassis supplies with fan or convection cooling, medical-standard supplies, DIN rail DC-DC converters and many other formats. Each series has a datasheet that lists all output voltages, derating curves and approvals. The standard catalogue format suits machine builders, panel builders and maintenance teams that need a documented, replaceable supply rather than a custom design.

Frequently Asked Questions