MEAN WELL ADD-55B is a dual-output power supply with battery charger with 27.6 V / 5 V / 26.5 V channels and a total rated output of 55.12 W. The main load, 5 V auxiliary load and battery-charging channel share the unit’s power budget. Apply the specified cooling and load limits.
Product Datasheet
Download MEAN WELL ADD-55 Datasheet (PDF)
The ADD-55 section is on PDF pages 23, 24. Refer to the complete mechanical drawings and notes when planning installation.
Model and Output Architecture
| Complete order code |
ADD-55B |
| Series |
ADD-55 |
| Output arrangement |
Dual-Output Power Supply with Battery Charger |
| Input selection |
Universal AC input; no manual range-selection switch |
CH1 supplies the main DC load, CH2 supplies a separate 5 V load, and CH3 is the battery-charging channel. An external battery can provide the catalogue UPS function.
Use the complete order code to select the voltage combination. The channel numbers identify circuits within one power supply, not separate products.
Electrical Output Ratings
| Total rated output power |
55.12 W |
| CH1 voltage adjustment |
24–29 V |
| CH1 function |
Main regulated output |
| CH1 output voltage |
27.6 V |
| CH1 rated current |
1.3 A |
| CH1 current range |
0–2 A |
| CH1 ripple and noise maximum |
150 mVp-p |
| CH1 voltage tolerance |
±1% |
| CH1 line regulation |
±1% |
| CH1 load regulation |
±1% |
| CH2 function |
5 V auxiliary output |
| CH2 output voltage |
5 V |
| CH2 rated current |
3 A |
| CH2 current range |
0–4 A |
| CH2 ripple and noise maximum |
150 mVp-p |
| CH2 voltage tolerance |
±3% |
| CH2 line regulation |
±0.5% |
| CH2 load regulation |
±0.5% |
| CH3 function |
Battery-charging output |
| CH3 output voltage |
26.5 V |
| CH3 rated current |
0.16 A |
The total rated power is shared by all listed channels. Observe the total-power, individual-current, adjustment and cooling limits together; the maximum values of different current ranges are not a simultaneous-output guarantee.
CH1 adjustment does not establish an independently adjustable voltage range for the other channels. Check the connected load and, where used, the battery charging requirements before adjustment.
Voltage tolerance includes setting tolerance, line regulation and load regulation. Ripple/noise is measured at 20 MHz bandwidth using a 12-inch twisted-pair lead terminated with 0.1 µF and 47 µF capacitors in parallel.
Unlisted battery-channel ripple, regulation or current-range values are not specified as zero.
Input and Timing
| AC input voltage |
88–264 VAC |
| DC input voltage |
124–370 VDC |
| AC input frequency |
47–63 Hz |
| Typical efficiency |
74% |
| Typical AC input current |
1.6 A at 115 VAC; 1 A at 230 VAC |
| Typical cold-start inrush current |
20 A at 115 VAC; 40 A at 230 VAC |
| Leakage current |
<1 mA at 240 VAC |
| Set-up / rise time |
800 / 50 ms at 230 VAC; 1600 / 50 ms at 115 VAC, full load |
| Typical hold-up time |
80 ms at 230 VAC; 16 ms at 115 VAC, full load |
| Switching frequency |
45 kHz |
Unless otherwise stated, catalogue parameters are measured at 230 VAC input, rated load and 25°C ambient. Timing values retain their stated input and load conditions.
Connect the protective-earth terminal marked FG as shown in the wiring drawing.
Protection and Battery Operation
| Short-circuit protection |
Provided |
| Main-output overload threshold |
105–150% of rated output power |
| Overload recovery |
AC charging mode: hiccup with automatic recovery after fault removal; UPS mode: internal-fuse protection |
| CH1 over-voltage threshold |
28.98–37.26 V |
| Over-voltage recovery |
Hiccup mode; automatic recovery after fault removal |
| Battery-low protection |
Provided; numeric cutoff is not specified |
The over-voltage threshold is specified for CH1. It is not a separately guaranteed over-voltage threshold for every auxiliary or charging channel.
AC charging and battery-backup operation have different overload protection mechanisms. An internal-fuse response is not an automatic electronic restart. Check battery polarity and the battery manufacturer’s charging requirements before connection.
Optional Alarm Output
| Alarm availability |
Optional configuration |
| CN1 pin 1 |
Battery-low alarm below 82.5% ±2% of charge voltage |
| CN1 pin 2 |
AC-fail alarm |
| Normal alarm level |
0.8 V maximum |
| Abnormal alarm level |
5 V ±0.5 V |
Order and confirm the alarm-equipped configuration when these signals are required. The alarm threshold is distinct from battery-discharge cutoff. Obtain the mating arrangement and signal reference for the supplied option before wiring.
Terminal Assignments and Mating Parts
| Terminal 1 |
AC/L |
| Terminal 2 |
AC/N |
| Terminal 3 |
FG |
| Terminal 4 |
DC OUTPUT COM |
| Terminal 5 |
DC OUTPUT +V |
| Terminal 6 |
BAT. + |
| Terminal 7 |
BAT.−/COM |
| Terminal 8 |
DC/DC OUTPUT +5V |
Use the numbered terminal view for this exact series. NC means no connection. DC COM is the output return; FG is protective earth. Do not interchange them.
Connect the external battery only to BAT.+ and BAT.−/COM. The battery return and output common are identified in the terminal and block diagrams. Select wiring and battery protection for the actual installation.
Environment, Cooling and Derating
| Working ambient temperature |
−10 to +60°C, subject to the applicable cooling curve |
| Working humidity |
20–90% RH, non-condensing |
| Storage temperature |
−20 to +85°C |
| Storage humidity |
10–95% RH |
| Temperature coefficient |
±0.03%/°C from 0 to 50°C on CH1 |
| Vibration |
10–500 Hz, 2G; 10 minutes/cycle, 60 minutes each along X, Y and Z |
For horizontal mounting without a fan, the curve permits 70% load from −10 to 40°C, decreasing to 50% at 50°C. The no-fan curve ends at 50°C. With at least 18.2 CFM external airflow arranged 10 cm from the unit as shown, the curve rises from 80% at −10°C to 100% at 0°C and remains at 100% through 60°C.
Natural-convection operation does not mean unrestricted full rated power. Provide the specified external airflow when using the forced-air curve, and keep the ventilation path clear.
Above 2000 m altitude, apply an additional ambient-temperature derating of 3.5°C per 1000 m for fanless models or 5°C per 1000 m for fan models, as specified in the catalogue installation note.
Safety, EMC and Reliability
| Safety standards |
UL 62368-1; TÜV BS EN/EN 62368-1; EAC TP TC 004 approved |
| Input-to-output withstand voltage |
3 kVAC |
| Input-to-FG withstand voltage |
2 kVAC |
| Output-to-FG withstand voltage |
0.5 kVAC |
| Isolation resistance |
100 MΩ between I/P–O/P, I/P–FG and O/P–FG at 500 VDC, 25°C, 70% RH |
| EMC emission |
BS EN/EN 55032 (CISPR 32), Class B; BS EN/EN 61000-3-2 and -3; EAC TP TC 020 |
| EMC immunity |
BS EN/EN 61000-4-2, -3, -4, -5, -6, -8, -11; BS EN/EN 55035, light-industry level; EAC TP TC 020 |
| MTBF, Telcordia SR-332 |
2002.7K hours minimum |
| MTBF, MIL-HDBK-217F |
373.8K hours minimum at 25°C |
This power supply is a component for installation in final equipment. The catalogue EMC tests use a 360 × 360 mm metal plate, 1 mm thick. Verify EMC compliance again in the completed equipment.
The catalogue lists 100% full-load burn-in testing and a two-year warranty. MTBF is a reliability calculation, not a guaranteed operating lifetime.
Mechanical Installation and Related Equipment
| Catalogue dimensions |
159 × 97 × 38 mm (L × W × H) |
| Case reference |
901 |
| Drawing dimensional tolerance |
±1 mm |
| Catalogue unit-weight reference |
570 g |
| Catalogue packing |
0.57 kg; 24 pcs / 13.7 kg / 0.83 CUFT |
The mechanical drawing marks a 152.5 mm longitudinal mounting reference, 84.5 mm vertical reference, 2-M3 bottom holes, 3-M3 side holes and Ø3.5 mm holes. Use the exact drawing positions and keep clearance around the terminal block.
The unit weight is the catalogue PACKING reference per unit, not a measured net or shipping weight. Carton quantities and carton weight are separate packing references.
Select external wiring, ventilation and installation hardware to suit the actual load and enclosure. The cooling fan illustrated in the airflow setup is external; the drawing does not establish an included fan or a separate fan order code.
An external battery is required for backup operation. Choose it for the stated charging voltage and current and the required backup duration; the catalogue does not prescribe a complete battery order code or guarantee a backup time.
