Buffering with electrolytic capacitors instead of lead batteries Buffering of 24V loads Minimum hold-up time 0.2s at 20A Longer hold-up time at lower loads Clear status indication by status LED and signaling terminals Quick-connect spring-clamp terminals 3 Year warranty The buffer unit is a supplementary device for regulated DC24V power supplies. It buffers load currents during typical mains faults and load peaks. Rated voltage Voltage range Output voltage Working principle In times when the power DC supply provides sufficient Discharge voltages, the buffer unit stores energy in integrated electrolytic capacitors. In case of mains voltage fault, this energy is released again in a regulated process. Bridges mains faults without interruption Statistic show that 80% of DC Buffer Unit all mains fault lasts less than 0.2s. These mains faults are completely bridged by the buffer unit. This increases the reliability of the system as a whole. Extended hold-up time Once mains power fails or is switched off, the buffer DC Buffer Unit unit will continue to provide the load current for a defined period of time. Process data can be saved and processes can be terminated before the DC power switches off. Controlled restarts are subsequently possible. 3. ORDER NUMBERS Buffer Unit Accessory Output current Hold-up time Charging current Charging time Input current Power dissipation Temperature range Dimensions standby mode standby mode operational WxHxD Easy to handle, expandable and maintanance-free The buffer unit does not require Power Buffer any control wiring. It can be AC Supply Unit(s) added parallel to the load circuit at any given point. Buffer units DC can be switched in parallel to increase the output ampacity or the hold-up time. 4. MARKINGS 24, 20A, 200ms Wall mounting bracket Side mounting bracket Mating connector, Part of delivery May 2013 / Rev. 1.3 / DS-UF20.241-EN All parameters are specified at 24V, 20A, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0

INSTALLATION NOTES Mounting Orientation: The power terminal shall be located on top of the unit. Cooling Convection cooled, no forced air cooling required. Do not obstruct air flow! Installation clearances: Recommended installation clearances: 40mm on top of the unit, 20mm on the bottom of the unit, 0mm (or 15mm in case the adjacent device is a heat source) on the left and right side of the unit Intended use This buffer unit has been designed for use in panel board installations or other building-in applications where a suitable mechanical enclosure shall be provided to fulfil local requirements....

5. STANDBY MODE Input voltage Voltage range Input current Power dissipation Status lamp Active signal Ready signal DC 24V 24-28.8Vdc 80mA 1.9W permanent on high ohmic low ohmic Charging mode Charging mode 29s / 21s flashes 1.25Hz high ohmic high ohmic Standby mode 6. CHARGING MODE Charging current Charging time Status lamp Active signal Ready signal 1) Initial charging is the first charge after voltage is applied to the buffer unit. 2) Re-charging is the charging of the internal capacitors after voltage interruptions shorter than 2minutes. Fig. 6-1 Re-charging time, 24V Charge May 2013 / Rev....

7. BUFFER MODE Rated output current Current limitation Output voltage Ripple and noise voltage Hold-up time Activation threshold Status lamp Active signal Ready signal 20A 20A Electronically limited 22.5V Jumper in position “22.5V fixed” 1V below input typ. Jumper in position “Vin –1V” voltage max. 200mVpp 20Hz to 20MHz, 50Ohm min. 0.2s 22.5V, 20A typ. 0.31s 22.5V, 20A min. 28s 22.5V, 0.1A typ. 43s 22.5V, 0.1A To increase buffer current or extend hold-up time any given number of buffer units can be put in parallel typ. 22.5V Jumper in position “22.5V fixed” Buffering starts if terminal voltage...

8. FUNCTIONAL DIAGRAM Fig. 8-1 Functional diagram Status lamp Buffer Capacitor Charger & Inrush Limiter Safety and OverVoltage Protection ReversePolarity Protection Buffer Capacitor Shut-Down Buffer Capacitor Discharger Buffer Capacitor Chassis Ground Input / Output Voltage Monitor Back-up Level Selector Ready Monitor Active Monitor 9. FRONT SIDE AND USER ELEMENTS Fig. 9-1 I/O Power Port Quick-connect spring-clamp terminals, + Positive terminal - Negative terminal Chassis Ground to bond the housing Back-up threshold jumper 1-2: Variable mode Unit switches to buffer mode when input voltage decreases...

10. OPERATING DIAGRAM Fig. 10-1 Operating diagram V Mains Fig. 10-2 Signals schematic Hold-up Time Power Supply t Optocoupler high ohmic Optocoupler high ohmic Charging Mode Buffer Mode 11. ACTIVE AND READY SIGNAL, INHIBIT INPUT Active signal (Pin 7) Signal voltage Signal current Voltage drop across opto-coupler Leakage current Isolation Ready signal (Pin 8) Signal voltage Signal current Voltage drop across opto-coupler Leakage current Isolation Inhibit input (Pin 9) Signal voltage Signal current Shut-down threshold Isolation low ohmic while buffer capacitors are discharging 35Vdc 10mA 0.9V /...

12. TERMINALS AND WIRING Power terminal Type Solid wire Stranded wire AWG Ferrules Pull-out force Wire stripping length Bi-stable, quick-connect spring clamp terminals. IP20 Finger safe construction. Suitable for field- and factory installation. Shipped in open position. 2 0.5-6mm 0.5-4mm2 20-10AWG Allowed, but not required 10AWG:80N, 12AWG:60N, 14AWG:50N, 16AWG:40N (according to UL486E) 10mm / 0.4inch Fig. 12-1 Connecting a wire Use appropriate copper cables, that are designed for an operating temperature of 60°C Follow national installation codes and regulations! Ensure that all strands of...

14. EMC The unit is suitable for applications in industrial environment as well as in residential, commercial and light industry environment without any restrictions. CE mark is in conformance with EMC guideline 89/336/EEC and 93/68/EEC and the low-voltage directive (LVD) 73/23/EWG. A detailed EMC Report is available on request EMC Immunity Electrostatic discharge 1) Electromagnetic RF field Fast transients (Burst) Surge voltage Conducted disturbance Contact discharge Air discharge 80MHz-1GHz + +/housing 0,15-80MHz Criterion A Criterion A Criterion A Criterion A Criterion A Criterion A Criterion...