The MEAN WELL DRC-40A is a 13.8 V DIN rail security power supply with a 1.9 A CH1 load output and a 1 A CH2 battery-charging output, sharing a 40.02 W total rating. It provides DC-UPS battery backup, free-air convection cooling and standard TTL open-collector AC OK and battery-low alarms.
Product Datasheet
Download MEAN WELL DRC-40 Datasheet (PDF)
The DRC-40 section is on PDF pages 1, 2, 3, 4, 5. Refer to the complete mechanical drawings and notes when planning installation.
Model and Two-Channel Ratings
| Full model |
DRC-40A |
| Series |
DRC-40 |
| Voltage code |
A: 13.8 V output; 12 V nominal battery application |
| CH1 output voltage |
13.8 V |
| CH1 rated current |
1.9 A |
| CH2 charge voltage |
13.8 V |
| CH2 rated charging current |
1 A |
| Rated total output power |
40.02 W |
| CH1 output current range |
0–2.9 A |
| CH1 voltage adjustment |
12–15 V |
| CH1 maximum ripple and noise |
120 mVp-p |
| CH1 voltage tolerance |
±1.0% |
| CH1 line regulation |
±0.5% |
| CH1 load regulation |
±0.5% |
CH1 supplies the load and CH2 charges the external battery. The two channels share the 40.02 W total output limit; their current ratings are not separate power allowances. The higher CH1 current-range limit must be used within the combined output-power budget.
The 12 V figure identifies the nominal battery application, while the catalogue specifies 13.8 V at both output channels. Select a battery suitable for the charging voltage and application, and connect it to the dedicated battery terminals.
Input and Electrical Performance
| Input voltage range |
90–264 VAC; 127–370 VDC |
| Input frequency |
47–63 Hz |
| Typical efficiency |
86% |
| Typical AC input current |
0.8 A at 115 VAC; 0.6 A at 230 VAC |
| Typical cold-start inrush current |
30 A at 115 VAC; 60 A at 230 VAC |
| Set-up / rise time at full load |
400 / 50 ms at 230 VAC; 800 / 50 ms at 115 VAC |
| Typical hold-up time at full load |
50 ms at 230 VAC; 10 ms at 115 VAC |
Unless otherwise stated, specifications are measured at 230 VAC input, rated load and 25°C ambient. Ripple and noise are measured at 20 MHz bandwidth with a 12-inch twisted pair terminated in parallel 0.1 µF and 47 µF capacitors. Voltage tolerance includes set-up tolerance, line regulation and load regulation.
Set-up time is measured at the first cold start. Repeated input on/off switching may increase the set-up time.
Battery Backup and Protection
| Short-circuit and overload protection |
Hiccup mode; automatic recovery after the fault is removed |
| Overload threshold |
105–150% of rated output power |
| CH1 overvoltage threshold |
14.49–18.63 V |
| Overvoltage recovery |
Output shutdown; reapply input power to recover |
| Battery low-voltage cut-off |
10 ± 0.5 V |
| Battery reverse-polarity protection |
Fuse protection |
With AC mains present, the supply powers the load and charges the battery simultaneously. When AC fails, the battery supplies the load through the backup connection. The battery is external to the power supply.
A battery below the specified cut-off voltage cannot perform AC-reset charging, as stated in the catalogue. Check battery condition before relying on automatic restart after a deeply discharged state. Battery-low signalling occurs before the separate cut-off threshold.
AC OK and Battery-Low Alarms
| Alarm interface |
TTL open collector, standard version |
| Maximum external alarm voltage |
50 V |
| Maximum alarm sink current |
30 mA |
| Alarm low-state voltage |
0.3 V maximum at 30 mA |
| AC OK signal |
Low when the supply is on; high or open when it is off |
| Battery-low signal |
Low below 11 V; high or open above 11 V |
| AC OK terminals |
TB2 pins 5 and 6 |
| Battery-low terminals |
TB2 pins 7 and 8 |
The alarm outputs require an external voltage source and resistor. In the open-collector diagram, pin 6 is the AC OK collector and pin 8 is the battery-low collector; pins 5 and 7 are the respective returns. Observe the 50 V / 30 mA limits; these terminals do not supply a powered alarm voltage.
A relay-contact version is an optional configuration. Confirm the required interface and complete ordering details before purchase; the standard model described here uses TTL open-collector signalling.
Terminal Connections
| TB1 input terminal assignment |
1: AC/L or DC+; 2: AC/N or DC−; 3: FG |
| TB2 load and battery assignment |
1: −V; 2: +V; 3: Bat+; 4: Bat− |
| TB2 alarm assignment |
5–6: AC OK; 7–8: Battery Low |
| Output-terminal drawing pitch |
3.81 mm |
| Input-terminal drawing pitch |
7.5 mm |
For DC input, connect positive to AC/L and negative to AC/N. Connect the load to +V / −V and the external battery to Bat+ / Bat−, following the indicated polarities. FG is the protective-earth connection.
Use the terminal numbers in the mechanical drawing for this model; load, battery and alarm terminals have different functions.
Cooling and Operating Limits
| Cooling |
Free-air convection |
| Installation orientation for thermal curve |
Vertical |
| Working temperature |
−30 to +70°C, subject to derating |
| Ambient-temperature load curve |
100% through 55°C; reduce to 60% at 70°C |
| Input-voltage load curve |
90% at 90 VAC; 100% at 100–264 VAC, 60 Hz |
| Working humidity |
20–90% RH, non-condensing |
| Storage temperature and humidity |
−40 to +85°C; 10–95% RH |
| CH1 temperature coefficient |
±0.03%/°C, 0–55°C |
| Vibration |
10–500 Hz, 2 G; 10 minutes per cycle, 60 minutes on each X, Y and Z axis |
Apply the input-voltage and ambient-temperature limits together, including battery-charging demand in the total power budget. Do not operate the unit at its full rating throughout the entire stated temperature range.
Above 2000 m, reduce the allowable ambient temperature by 3.5°C per 1000 m for this fanless unit.
The −30 to −20°C portion of the thermal curve is specified for 230 VAC input only. For permanent full-power operation, the recommended clearances are 40 mm above, 20 mm below and 5 mm on either side; increase the clearance to an adjacent heat source to 15 mm.
Safety and EMC
| Approved safety standards |
UL 62368-1; TUV BS EN / EN 62368-1; EAC TP TC 004; AS/NZS 60950.1 |
| Withstand voltage |
Input–output: 3 kVAC; input–FG: 2 kVAC; output–FG: 0.5 kVAC |
| Isolation resistance |
Input–output, input–FG and output–FG: 100 MΩ at 500 VDC, 25°C and 70% RH |
| EMC emission |
BS EN / EN 55032 (CISPR 32), Class B; BS EN / EN 61000-3-2 and -3-3; EAC TP TC 020 |
| EMC immunity |
BS EN / EN 61000-4-2, -3, -4, -5, -6, -8 and -11; BS EN / EN 55035 and 61204-3, light-industry level; EAC TP TC 020 |
| Limited-power-source feature |
LPS |
The power supply is a component for installation in final equipment. Check the completed installation against the applicable EMC and safety requirements.
Mechanical Installation and Supply Scope
| Catalogue dimensions, W × H × D |
40 × 90 × 100 mm |
| Drawing case number |
962A |
| Drawing dimensional tolerance |
±1 mm |
| Supported DIN rails |
TS35/7.5 or TS35/15 |
| Mass, catalogue PACKING reference per unit |
300 g |
| Catalogue packing |
0.3 kg; 42 units / 13.6 kg / 0.82 CUFT |
| Minimum MTBF, Telcordia / MIL-HDBK-217F |
2496.2K / 536.6K hours |
| Warranty |
3 years |
The DIN rail shown in the installation drawing is a reference and is not included with the unit. Follow the corresponding case drawing and installation instructions for mounting and access to the terminals and +V ADJ control.
The front-panel DC OK LED indicates power-on status. MTBF values refer to Telcordia SR-332 (Bellcore) and MIL-HDBK-217F at 25°C, respectively.
The catalogue specifies a 100% full-load burn-in test.
