Siemens SITOP UPS500S Ex and UPS501S Ex DC-UPS Operating Instructions

Introduction and Overview

These operating instructions provide detailed information for the Siemens SITOP UPS500S Ex and UPS501S Ex DC-UPS units. These devices are designed for mounting on a DIN rail (TH 35-15/7,5) and are used to buffer a portion of the load current for 24V DC SITOP power supplies.

The DC-UPS basic unit connects to the output of a 24V DC power supply. Up to three expansion modules can be connected to the basic unit. When the primary 24V DC supply fails or drops below a set threshold, the loads are supplied by the DC-UPS via its internal capacitors or expansion modules.

Key features include adjustable cut-in threshold, charging power, and buffering time via DIP switches. The units also feature LEDs for status indication, potential-free relay contacts, and a USB interface for remote control and signaling.

Safety Warnings:

• Only qualified personnel should work on or around this equipment.
• Proper handling, storage, and installation are crucial for safe operation.
• Only trained personnel may open the unit due to electrostatically sensitive components (ESD).
• Packaging and packing aids should be recycled. The product itself should not be disposed of as normal domestic waste.

Technical Data

Input Quantities:

• Rated input voltage: 24V DC
• Operating voltage range: 22 to 29V DC
• Max. input current (charging): 17.5A DC
• Max. input current (charged): 15.2A DC
• Power loss (charging): approx. 11.0W
• Power loss (charged): approx. 9.0W
• Charging time (low power, basic unit): approx. 220s
• Charging time (high power, basic unit): approx. 120s
• Charging time (low power, basic + 1 expansion): approx. 430s
• Charging time (high power, basic + 1 expansion): approx. 220s

Output Quantities:

• Rated output DC voltage: 24V DC
• Rated output current: 15A DC
• Output current range: 0 to 15A DC
• End-of-charge voltage: 21.8V DC
• Charging current: 1A or 2A
• Buffering time (15A load, basic unit): 9s (typ.)
• Buffering time (15A load, basic + 1 expansion): 20s (typ.)

Settings

Setting the Cut-in Threshold:

This setting determines when the DC-UPS switches to floating operation if the input voltage drops. It is adjustable via three DIP switches in 0.5V steps from 22.0V to 25.5V DC. The delivery state is 22.5V DC ± 0.1V.

Setting the Charging Current:

This setting determines how quickly the buffer ready state is restored. The charging current is set via a DIP switch to typ. 1A or typ. 2A. The delivery state is 1A.

Setting the Operating State ON/OFF:

For normal operation, the unit must be set to "ON" (delivery state is "OFF"). This can be done via a DIP switch or by connecting terminals X2.9 and X2.10. Setting to "OFF" prevents unintentional capacitor discharge but disables floating operation upon power loss. The "ON/OFF" status is polled approximately every 20 seconds during normal operation.

Setting the Buffering Time:

The buffering time can be set in 10s steps from 5s to 315s using five DIP switches. A switch (Switch 5) allows selection between terminating buffering after a prespecified time or when the capacitors reach their deep discharge threshold (maximum buffering time). The delivery state is maximum buffering time. A remote signal can initiate the timer for termination.

Interruption of the Output Voltage:

A DIP switch can be used to select whether the output voltage is interrupted for 5 seconds at the end of the buffering time. The delivery state is no interruption. With the "max. time" setting, an interruption is initiated by the remote signal.

Protective and Monitoring Functions

• Reverse Polarity Protection: The unit is electronically protected against input voltage polarity reversal.
• Overcurrent and Short-Circuit Protection: Protected by internal dynamic and static current limitation. Dynamic limitation to typ. 25A. Static limitation shuts down the output at >18A after approx. 110ms (short-circuit) or 200ms (overload). An internal 20A fuse provides fault protection. Automatic restarts occur every 20s in normal operation. In floating operation, the module shuts down in store mode and restarts upon return to normal operation.

Signaling

The DC-UPS provides status information via LEDs and relay contacts:

• Normal Operation (Green LED, Relay X2.2-X2.3 closed): Input voltage is higher than the cut-in threshold.
• >85% Charge (Second Green LED, Relay X2.7-X2.8 closed): Capacitor charge is above 85%.
• Floating Operation (Yellow LED, Relay X2.1-X2.2 closed): Input voltage is below the cut-in threshold.
• Buffering Not Ready (Red LED, Relay X2.4-X2.5 closed): Indicates issues like "OFF" state, defective capacitors, or capacitor voltage < 7V.

The "Alarm" signal in floating operation indicates capacitor voltage has dropped below 12V, and disconnection is imminent. After termination (overload, short circuit, etc.), the red LED goes out, but the relay contact remains closed. Relay contacts are rated for 30V DC / 1A (SELV (ES1) must be maintained).

USB Interface: Signals are also output via a PC-compatible USB interface (Specification 2.0, Full Speed). A software tool for reading signals is available online. Remote signals "R" (Timerstart) and "S" (Shutdown) can be sent via USB.

Environment and Standards

Environment:

• Operating conditions: EN 60721-3-3, climate model 3K3 (5-85% relative humidity, 1-25 g/m³ absolute humidity, no condensation).
• Stationary, weather-protected, pollution degree 2.
• Storage/shipment temperature: -40 to +70°C.
• Operating temperature: 0 to +60°C.
• Overvoltage category: II to 2000 m.

Standards:

• Degree of protection: IP20 (EN60529).
• Protection class III, designed for regulated 24V DC power supplies.
• Complies with UL 508/CSA C22.2 File E197259.
• ATEX directive 2014/34/EU; EN 60079-0; EN 60079-7.
• Also certified by DNV GL and ABS.

Installation Instructions

• Mount vertically with input/output terminals and air slots at the bottom for effective cooling. Maintain at least 50mm clearance above and below the unit.
• Install at least 50cm away from commutating chokes to minimize EMI and thermal strain.
• Route interface (USB) and control leads separately from power leads. Maintain at least 10cm distance from power leads to minimize EMI.
• For use in hazardous areas, install in an enclosure with IP54 or higher rating, complying with EN 60079-0.
• Always switch off and secure the main plant switch before installation or repair work. Refer to SITOP power operating instructions.

Connection and Terminal Assignments

Caution: External circuitry for all terminals must meet SELV (ES1) requirements per EN61204-7.

ATEX / Standards Compliance

6EP1933-2EC51-8AA0:

• ATEX: II 3G Ex ec nC IIC T4 Gc
• Warning: Separate expansion modules must be in non-hazardous areas only. For hazardous areas, an enclosure/cabinet rated min. IP54 is required, complying with EN 60079-0:2009 and/or EN60079-7:2010. DIP switches should not be used in hazardous areas. Only locking USB cables (Part no: Y-Con IP20LOCK-104) are permitted.
• Warning (German): Connections must only be disconnected in non-explosive environments. Switch operation must only be performed in non-explosive environments. Signal plugs in Ex areas require additional fixings per EN 60079-7.

6EP1935-5PG01-8AA0:

• ATEX: II 3G Ex ec IIC T4 Gc
• Warning: Separate expansion modules must be in non-hazardous areas only. For hazardous areas, an enclosure/cabinet rated min. IP54 is required, complying with EN 60079-0:2009 and/or EN60079-7:2010.
• Warning (German): Connections must only be disconnected in non-explosive environments.
• Warning: Separate terminals in non-hazardous areas only.