MEAN WELL DIN Rail System Backup & UPS Solutions
DBUF Series (Buffer Modules) & DUPS Series (DC UPS Modules) | 20A & 40A Systems | 24V System Reliability
Bulletproof Your 24V Industrial Control Systems
Power grid fluctuations, brownouts, and sudden blackouts can cause critical PLCs, motor drives, and industrial PCs to reset or fail. MEAN WELL provides two distinct layers of DIN rail defense: The DBUF Buffer Modules for short-term micro-interruptions, and the DUPS DC UPS Modules for extended battery-backed bridging.
Choosing Your Backup Strategy
- DBUF Series (Capacitor Buffer): Uses maintenance-free electrolytic capacitors to store energy. Perfect for bridging short AC faults (up to 350ms at full load) without the hassle, lifespan issues, or hazardous materials of batteries.
- DUPS Series (Battery UPS): Pairs with an external lead-acid battery to provide continuous 24V DC power for minutes or hours during a complete blackout, enabling safe machine shutdowns or continuous operation.
DBUF20 & DBUF40: Maintenance-Free Buffer Modules
The DBUF series is wired in parallel with your primary 24VDC power supply. It passively charges its internal capacitors and instantly steps in to provide power if the main DC bus voltage dips.
| Model Series | DBUF20-24 | DBUF40-24 |
|---|---|---|
| Working Voltage | 24VDC | 24VDC |
| Max Buffer Current | 20A | 40A |
| Buffering Time (Typ. @ Full Load) | 350ms (at 20A) | 250ms (at 40A) |
| Buffering Time (Typ. @ Half Load) | 700ms (at 10A) | 500ms (at 20A) |
| Charge Time (Max) | 25 seconds | 35 seconds |
DUPS20 & DUPS40: Uninterruptible DC UPS Modules
The DUPS series bridges the gap between your 24V power supply, your system load, and an external battery bank (4AH ~ 135AH), serving as an intelligent charging and switching controller.
| Model Series | DUPS20 | DUPS40 |
|---|---|---|
| System Voltage | 24VDC | 24VDC |
| Rated Current | 20A | 40A |
| Battery Type Supported | Lead-Acid (4AH ~ 135AH) | Lead-Acid (4AH ~ 135AH) |
| Charge Current | 2A | 2A |
Comprehensive Battery Protection
- Deep Discharge Protection: To prevent permanent battery damage, the UPS automatically disconnects the battery if the voltage drops below 21V~21.5V.
- Reverse Polarity Protection: Internal circuits prevent damage if the battery is wired backward, easily reset once the fault is cleared.
Smart System Diagnostics & Alarms
Both series provide clear visual indicators and external signals to keep central PLCs informed of the power status.
DBUF Series (Buffer) Signals
- Ready (R): Indicates capacitors are fully charged.
- Buffering (B): Indicates the module is actively discharging and supplying power to the load.
DUPS Series (DC UPS) Alarms
- DC BUS OK: Relay contact triggers and green LED changes if the main DC voltage drops out of standard range.
- Battery Fail: Relay contact and red LED alert you if the battery voltage drops too low during the periodic test, indicating a dead or missing battery.
- Battery Discharge: Relay contact and yellow LED activate when the system is running exclusively on battery power.
Physical Dimensions & Environment
Engineered for standard TS-35 DIN rails, these modules are designed to sit right next to your primary power supplies.
Dimensions (W * H * D)
- DBUF20-24: 63 * 125.2 * 114.9 mm
- DBUF40-24: 63 * 125.2 * 114.9 mm
- DUPS20: 40 * 125.2 * 113.5 mm
- DUPS40: 63 * 125.2 * 113.5 mm
- DBUF Series: -25°C to +75°C (Highly robust due to removing battery chemistry).
- DUPS Series: -30°C to +70°C (Note: External battery performance is heavily dependent on ambient temperature).
