The MEAN WELL DRC-180B is a 27.6 V DIN rail security power supply with a 4.5 A CH1 load output and a 2 A CH2 battery-charging output, sharing a 179.4 W total rating. It provides DC-UPS battery backup, free-air convection cooling and relay-contact AC OK and battery-low alarms.
Product Datasheet
Download MEAN WELL DRC-180 Datasheet (PDF)
The DRC-180 section is on PDF pages 16, 17, 18, 19, 20. Refer to the complete mechanical drawings and notes when planning installation.
Model and Two-Channel Ratings
| Full model |
DRC-180B |
| Series |
DRC-180 |
| Voltage code |
B: 27.6 V output; 24 V nominal battery application |
| CH1 output voltage |
27.6 V |
| CH1 rated current |
4.5 A |
| CH2 charge voltage |
27.6 V |
| CH2 rated charging current |
2 A |
| Rated total output power |
179.4 W |
| CH1 output current range |
0–6.5 A |
| CH1 voltage adjustment |
24–29 V |
| CH1 maximum ripple and noise |
240 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 179.4 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 24 V figure identifies the nominal battery application, while the catalogue specifies 27.6 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 |
90% |
| Typical AC input current |
2.5 A at 115 VAC; 1.5 A at 230 VAC |
| Typical cold-start inrush current |
35 A at 115 VAC; 70 A at 230 VAC |
| Set-up / rise time at full load |
2000 / 30 ms at 230 VAC and 115 VAC |
| Typical hold-up time at full load |
20 ms at 230 VAC and 115 VAC |
| Power factor correction |
Built-in active PFC |
| Typical power factor at full load |
PF ≥ 0.95 at 230 VAC; PF ≥ 0.98 at 115 VAC |
| Leakage current |
Less than 2 mA at 240 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 |
30.5–37.7 V |
| Overvoltage recovery |
Output shutdown; reapply input power to recover |
| Battery low-voltage cut-off |
20 ± 1 V |
| Battery reverse-polarity protection |
Fuse protection |
| Overtemperature protection |
Output shutdown; reapply input power to recover |
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 |
Relay contacts |
| Maximum external alarm voltage |
30 V |
| Maximum alarm contact current |
1 A |
| AC OK signal |
Closed when the supply is on; open when it is off |
| Battery-low signal |
Closed below 22 V; open above 22 V |
| AC OK terminals |
TB3 pins 1 and 2 |
| Battery-low terminals |
TB3 pins 3 and 4 |
Use an external voltage source and resistor for alarm detection, within the 30 V / 1 A limits. The relay contacts are status interfaces, not additional supply outputs. Low or short corresponds to a closed contact; high or open corresponds to an open contact.
The AC OK relay RL1 enters hiccup operation while overload protection is active. Battery-low indication and battery cut-off are separate functions with different voltage thresholds.
Terminal Connections
| TB1 input terminal assignment |
1: FG; 2: AC/N; 3: AC/L |
| TB2 load and battery assignment |
1: +V; 2: −V; 3: Bat+; 4: Bat− |
| TB3 alarm assignment |
1–2: AC OK; 3–4: Battery Low |
Connect the load to +V and −V and the battery to Bat+ and Bat−. The −V and Bat− terminals must not be shorted. Keep the two return circuits distinct as shown in the connection diagram.
The input terminal order differs from the smaller DRC models. Use the case 979G terminal markings when wiring the installation, and connect FG to protective earth.
Cooling and Operating Limits
| Cooling |
Free-air convection |
| Installation orientation for thermal curve |
Vertical |
| Working temperature |
−20 to +70°C, subject to derating |
| Ambient-temperature load curve |
100% through 45°C; reduce to 50% at 70°C |
| Input-voltage load curve |
80% at 90 VAC; 100% at 100–264 VAC, 60 Hz |
| Working humidity |
20–90% RH, non-condensing |
| Storage temperature and humidity |
−20 to +85°C; 10–95% RH, non-condensing |
| CH1 temperature coefficient |
±0.03%/°C, 0–40°C |
| Vibration |
10–500 Hz, 2 G; 10 minutes per cycle, 60 minutes on each X, Y and Z axis |
| Operating altitude / overvoltage category |
Up to 5000 m / OVC II |
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 catalogue assigns overvoltage category II under Dekra BS EN / EN 62368-1 for altitude up to 5000 m; altitude derating still applies.
Safety and EMC
| Approved safety standards |
UL 62368-1; Dekra BS EN / EN 62368-1; EAC TP TC 004; AS/NZS 62368.1 |
| 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 |
| Conducted and radiated emissions |
BS EN / EN 55032 (CISPR 32), Class B |
| EMC immunity framework |
BS EN / EN 55024 |
| ESD immunity |
8 kV air, level 3; 4 kV contact, level 2; criterion A |
| Radiated immunity |
BS EN / EN 61000-4-3: 3 V/m, level 2; criterion A |
| EFT / burst immunity |
BS EN / EN 61000-4-4: 1 kV, level 2; criterion A |
| Surge immunity |
BS EN / EN 61000-4-5: 1 kV line–line / 2 kV line–earth, level 3; criterion A |
| Conducted immunity |
BS EN / EN 61000-4-6: 3 V, level 2; criterion A |
| Magnetic-field immunity |
BS EN / EN 61000-4-8: 1 A/m, level 1; criterion A |
| Voltage dips and interruptions |
BS EN / EN 61000-4-11: >95% dip for 0.5 period; 30% dip for 25 periods; >95% interruption for 250 periods |
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 |
63 × 125.2 × 115 mm |
| Drawing case number |
979G |
| Drawing dimensional tolerance |
±1 mm |
| Supported DIN rails |
TS35/7.5 or TS35/15 |
| Mass, catalogue PACKING reference per unit |
710 g |
| Catalogue packing |
0.71 kg; 12 units / 10.5 kg / 1.02 CUFT |
| Minimum MTBF, Telcordia / MIL-HDBK-217F |
1536.3K / 245.6K 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.
