Powerbox PB251A-CM SERIES DC-UPS / Battery Charger
The Powerbox PB251A-CM Series DC-UPS and Battery Charger is a compact, high-reliability power solution designed to deliver up to 330W of continuous DC power with intelligent battery backup functionality. It supports critical infrastructure across a wide range of sectors with a focus on reliability, simplicity, and long-term serviceability.
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Features
- Compact, Intelligent DC-UPS: A space-efficient 220–330W system with true off-line DC-UPS functionality, delivering uninterrupted DC power by seamlessly switching to battery backup during mains failure. Built-in battery charging and management make it ideal for wall-mounted or enclosed control systems in security, automation, and utility applications.
- Trusted in Security and Industrial Environments: Widely used in electronic security, access control, and industrial automation systems—including applications within water utilities, where dependable power for monitoring and control infrastructure is essential.
- Built-In Battery Management: Includes constant float voltage, current limiting, a separate battery charging output, and integrated battery low-voltage disconnect (LVD) for full protection and backup continuity.
- Alarm and Status Monitoring: Dual green LED indicators and voltage-free relay contacts monitor DC OK and Battery OK conditions, alerting users to power loss, battery disconnection, or low-voltage conditions.
- Flexible Installation and Environmental Protection: Multiple mounting centre options and pluggable terminal blocks support easy integration in tight enclosures. An optional conformal coating is available to protect internal electronics in moisture-prone or harsh environments.
- Optional Enhancements for System Integration: Supports SNMP V1 network monitoring (Option -N), battery charge current limiting (BCL), and temperature compensation via external probes—enabling tailored performance and remote visibility.
| INPUT | |||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Input Voltage: | 190...264Vac, or 225...400Vdc | ||||||||||||||||||||||||||||||||||||||||||||||||
| Frequency: | 45 to 65 Hz | ||||||||||||||||||||||||||||||||||||||||||||||||
| Input Current: | 1.4A maximum | ||||||||||||||||||||||||||||||||||||||||||||||||
| Inrush current: | 10A maximum | ||||||||||||||||||||||||||||||||||||||||||||||||
| Line regulation: | 0.2%typical | ||||||||||||||||||||||||||||||||||||||||||||||||
| OUTPUT | |||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Output Voltage | 13.8Vdc, 27.6Vdc | ||||||||||||||||||||||||||||||||||||||||||||||||
| Output Current |
13.8Vdc: 16A / 20A (-H) 27.6Vdc: 11A / 12A (-H) |
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| Load regulation | 0.5% typical | ||||||||||||||||||||||||||||||||||||||||||||||||
| Ripple & noise 100 MHz bandwidth |
28mVp-p (13.8Vdc output) 55mVp-p (27.6Vdc output) |
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| Efficiency | > 80% | ||||||||||||||||||||||||||||||||||||||||||||||||
| PROTECTION | |||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Current limit |
Load circuit - Constant current Battery circuit - Constant current |
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| Short circuit protection | Indefinite, auto-resetting | ||||||||||||||||||||||||||||||||||||||||||||||||
| Over-voltage protection | 17.5 to 20V latching (13.8Vdc output) 31.5 to 39V latching (27.6Vdc output) |
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| Isolation |
Input to Output: 4.2Kvdc 1 min Output to Ground: 2.1Kvdc 1 min Output to Ground: 700Vdc 1 min |
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| ENVIRONMENTAL | |||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Operating temperature |
0 to 70°C ambient Derating from full power at Ta = 25°C to 0W at Ta=70°C at -2.22%/°C |
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| Humidity | 5 to 90% relative humidity (non-condensing) | ||||||||||||||||||||||||||||||||||||||||||||||||
| Over-temperature protection | Automatic & auto-resetting | ||||||||||||||||||||||||||||||||||||||||||||||||
| Cooling requirement | Natural convection | ||||||||||||||||||||||||||||||||||||||||||||||||
| STANDARDS & APPROVALS | |
|---|---|
| C-Tick | AS/NZS CISPR11 Group 1 Class A. |
| Safety | Complies with AS/NZS 60950, class 1, NSW Office of Fair Trading Approval N20602 |
| EMC | Emissions comply with AS/NZS CISPR11,Group 1, Class B. Complies with ACA EMC Scheme,Safety & EMC Regulatory Compliance Marked |
| ALARMS & BATTERY FUNCTIONS | |||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| DC OK alarm | Green LED : ON=OK voltage free change over relay contacts (32V,1A) Alarms on loss of AC mains power or failure of off-line AC/DC converter / battery charger | ||||||||||||||||||||||||||||||||||||||||||||||||
| Battery OK alarm | Green LED : ON=OK voltage free change over relay contacts(32V,1A) Alarms on battery low voltage 11V, failure of battery fuse or battery disconnected. Alarm cancelled when fuse or battery replaced, or AC input restored | ||||||||||||||||||||||||||||||||||||||||||||||||
|
Battery low voltage disconnect (LVD) |
10.2 to 12.6V for 12V battery, adjustable 20.4 to 25.2V for 24V battery,adjustable Indicated by voltage-free changeover relay contacts & green LED: ON=BATT OK | ||||||||||||||||||||||||||||||||||||||||||||||||
| Low voltage disconnect | 9.6 to 12V for 12V battery, adjustable 19.2 to 24V for 24V battery, adjustable |
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| Charger over-load protection | Auto-resetting electronic circuit breaker | ||||||||||||||||||||||||||||||||||||||||||||||||
| Reverse polarity protection | Internal battery fuse | ||||||||||||||||||||||||||||||||||||||||||||||||
| Battery to load voltage drop | 0.2 to. 0.25V typical | ||||||||||||||||||||||||||||||||||||||||||||||||
| OPTIONAL FEATURES | |||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Battery Charge Current Limit (BCL) |
Factory set to any value within adjustment the range. For the PB251A-12CM, battery charging current limit can be set from 2A to 20.5A . For the PB251A-24CM battery charging current limit can be set from 1A to 12.5A . Battery charging current option can be specified when ordering e.g. PB251A-12CM-10 for 10A setting. |
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| Heatsink | Option H: Supplementary heatsink | ||||||||||||||||||||||||||||||||||||||||||||||||
| Network enabled | Option N: Internal network card in conjunction with PB251A becomes a network enabled device combining the benefits of SNMP V1, XML and embedded webpage. | ||||||||||||||||||||||||||||||||||||||||||||||||
| Temperature compensation |
Option T: 2.5m cable probe Option T5: 5m cable probe Float voltage set to 2.3V/cell at 25°C with compensation of 3.3mv/°C cell |
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| Conformal Coating | Option CC: Tropic protection for moist areas | ||||||||||||||||||||||||||||||||||||||||||||||||
| MECHANICAL | |
|---|---|
| Input connector | IEC60320 inlet,10A Class 1 2 meter IEC mains cord with Australian plug is supplied with each unit |
| Output/Battery connector | 4 way pluggable screw terminal block Suitable for up to 4mm² wire |
| Alarm terminal | 6 way pluggable screw terminal block Suitable for up to 1.5mm² wire |
| Case size | 264 L x 172 W x 67 H mm |
| Case size with heatsink | 264 L x 186 W x 67 H mm |
| Weight | 1.9kg |
| Weight with heatsink | 2.1kg |
| Rack mount option | Refer to PB251-RM Series |
| Security Cabinet | View WMBB-C-S Security Cabinet |
| MODEL NUMBER | OUTPUT VOLTAGE | LOAD CURRENT | BATTERY CHARGE CURRENT ¹ | TOTAL CURRENT | OUTPUT POWER |
|---|---|---|---|---|---|
| PB251A-12CM | 13.8V | 14A | 2A | 16A | 220W |
| PB251A-12CM-H | 13.8V | 18A | 4A | 20A | 275W |
| PB251A-24CM | 27.6V | 9A | 2A | 11A | 300W |
| PB251A-24CM-H | 27.6V | 10A | 2A | 12A | 330W |
Notes:
¹ Other optional BCL, Battery Charging Limit, available on request (factory set).
² Example models number, PB251A-12CM-H-N-05 - Includes heat sink, network card and 5A battery charge current limit.
| INPUT | |||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Input Voltage: | 190...264Vac, or 225...400Vdc | ||||||||||||||||||||||||||||||||||||||||||||||||
| Frequency: | 45 to 65 Hz | ||||||||||||||||||||||||||||||||||||||||||||||||
| Input Current: | 1.4A maximum | ||||||||||||||||||||||||||||||||||||||||||||||||
| Inrush current: | 10A maximum | ||||||||||||||||||||||||||||||||||||||||||||||||
| Line regulation: | 0.2%typical | ||||||||||||||||||||||||||||||||||||||||||||||||
| OUTPUT | |||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Output Voltage | 13.8Vdc, 27.6Vdc | ||||||||||||||||||||||||||||||||||||||||||||||||
| Output Current |
13.8Vdc: 16A / 20A (-H) 27.6Vdc: 11A / 12A (-H) |
||||||||||||||||||||||||||||||||||||||||||||||||
| Load regulation | 0.5% typical | ||||||||||||||||||||||||||||||||||||||||||||||||
| Ripple & noise 100 MHz bandwidth |
28mVp-p (13.8Vdc output) 55mVp-p (27.6Vdc output) |
||||||||||||||||||||||||||||||||||||||||||||||||
| Efficiency | > 80% | ||||||||||||||||||||||||||||||||||||||||||||||||
| PROTECTION | |||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Current limit |
Load circuit - Constant current Battery circuit - Constant current |
||||||||||||||||||||||||||||||||||||||||||||||||
| Short circuit protection | Indefinite, auto-resetting | ||||||||||||||||||||||||||||||||||||||||||||||||
| Over-voltage protection | 17.5 to 20V latching (13.8Vdc output) 31.5 to 39V latching (27.6Vdc output) |
||||||||||||||||||||||||||||||||||||||||||||||||
| Isolation |
Input to Output: 4.2Kvdc 1 min Output to Ground: 2.1Kvdc 1 min Output to Ground: 700Vdc 1 min |
||||||||||||||||||||||||||||||||||||||||||||||||
| ENVIRONMENTAL | |||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Operating temperature |
0 to 70°C ambient Derating from full power at Ta = 25°C to 0W at Ta=70°C at -2.22%/°C |
||||||||||||||||||||||||||||||||||||||||||||||||
| Humidity | 5 to 90% relative humidity (non-condensing) | ||||||||||||||||||||||||||||||||||||||||||||||||
| Over-temperature protection | Automatic & auto-resetting | ||||||||||||||||||||||||||||||||||||||||||||||||
| Cooling requirement | Natural convection | ||||||||||||||||||||||||||||||||||||||||||||||||
| STANDARDS & APPROVALS | |
|---|---|
| C-Tick | AS/NZS CISPR11 Group 1 Class A. |
| Safety | Complies with AS/NZS 60950, class 1, NSW Office of Fair Trading Approval N20602 |
| EMC | Emissions comply with AS/NZS CISPR11,Group 1, Class B. Complies with ACA EMC Scheme,Safety & EMC Regulatory Compliance Marked |
| ALARMS & BATTERY FUNCTIONS | |||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| DC OK alarm | Green LED : ON=OK voltage free change over relay contacts (32V,1A) Alarms on loss of AC mains power or failure of off-line AC/DC converter / battery charger | ||||||||||||||||||||||||||||||||||||||||||||||||
| Battery OK alarm | Green LED : ON=OK voltage free change over relay contacts(32V,1A) Alarms on battery low voltage 11V, failure of battery fuse or battery disconnected. Alarm cancelled when fuse or battery replaced, or AC input restored | ||||||||||||||||||||||||||||||||||||||||||||||||
|
Battery low voltage disconnect (LVD) |
10.2 to 12.6V for 12V battery, adjustable 20.4 to 25.2V for 24V battery,adjustable Indicated by voltage-free changeover relay contacts & green LED: ON=BATT OK | ||||||||||||||||||||||||||||||||||||||||||||||||
| Low voltage disconnect | 9.6 to 12V for 12V battery, adjustable 19.2 to 24V for 24V battery, adjustable |
||||||||||||||||||||||||||||||||||||||||||||||||
| Charger over-load protection | Auto-resetting electronic circuit breaker | ||||||||||||||||||||||||||||||||||||||||||||||||
| Reverse polarity protection | Internal battery fuse | ||||||||||||||||||||||||||||||||||||||||||||||||
| Battery to load voltage drop | 0.2 to. 0.25V typical | ||||||||||||||||||||||||||||||||||||||||||||||||
| OPTIONAL FEATURES | |||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Battery Charge Current Limit (BCL) |
Factory set to any value within adjustment the range. For the PB251A-12CM, battery charging current limit can be set from 2A to 20.5A . For the PB251A-24CM battery charging current limit can be set from 1A to 12.5A . Battery charging current option can be specified when ordering e.g. PB251A-12CM-10 for 10A setting. |
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| Heatsink | Option H: Supplementary heatsink | ||||||||||||||||||||||||||||||||||||||||||||||||
| Network enabled | Option N: Internal network card in conjunction with PB251A becomes a network enabled device combining the benefits of SNMP V1, XML and embedded webpage. | ||||||||||||||||||||||||||||||||||||||||||||||||
| Temperature compensation |
Option T: 2.5m cable probe Option T5: 5m cable probe Float voltage set to 2.3V/cell at 25°C with compensation of 3.3mv/°C cell |
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| Conformal Coating | Option CC: Tropic protection for moist areas | ||||||||||||||||||||||||||||||||||||||||||||||||
| MECHANICAL | |
|---|---|
| Input connector | IEC60320 inlet,10A Class 1 2 meter IEC mains cord with Australian plug is supplied with each unit |
| Output/Battery connector | 4 way pluggable screw terminal block Suitable for up to 4mm² wire |
| Alarm terminal | 6 way pluggable screw terminal block Suitable for up to 1.5mm² wire |
| Case size | 264 L x 172 W x 67 H mm |
| Case size with heatsink | 264 L x 186 W x 67 H mm |
| Weight | 1.9kg |
| Weight with heatsink | 2.1kg |
| Rack mount option | Refer to PB251-RM Series |
| Security Cabinet | View WMBB-C-S Security Cabinet |
| MODEL NUMBER | OUTPUT VOLTAGE | LOAD CURRENT | BATTERY CHARGE CURRENT ¹ | TOTAL CURRENT | OUTPUT POWER |
|---|---|---|---|---|---|
| PB251A-12CM | 13.8V | 14A | 2A | 16A | 220W |
| PB251A-12CM-H | 13.8V | 18A | 4A | 20A | 275W |
| PB251A-24CM | 27.6V | 9A | 2A | 11A | 300W |
| PB251A-24CM-H | 27.6V | 10A | 2A | 12A | 330W |
Notes:
¹ Other optional BCL, Battery Charging Limit, available on request (factory set).
² Example models number, PB251A-12CM-H-N-05 - Includes heat sink, network card and 5A battery charge current limit.
Find the Right Model
| Model Number | Input Voltage (Vac) | Output Voltage (Vdc) | Output Current (A) | ||
|---|---|---|---|---|---|
|
PB251A-12CM | 190...264Vac 50/60Hz | 13.8Vdc | 16A (Default = 14A Load / 2A Battery) | |
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|
PB251A-12CM-H | 190...264Vac 50/60Hz | 13.8Vdc | 20A (Default = 16A Load / 4A Battery) | |
|
|
PB251A-24CM | 190...264Vac 50/60Hz | 27.6Vdc | 11A (Default = 9A Load / 2A Battery) | |
|
|
PB251A-24CM-H | 190...264Vac 50/60Hz | 27.6Vdc | 12A (Default = 10A Load / 2A Battery) |
Need help finding the right product model?
