User Manual

4.7 Supply Voltages
The SAPHIR unit is supplied with 24 VAC (±15%) or 26…35 VDC via plug-in terminal
strip X1 (terminals X1.1 and X1.2).
X1.1
X1.2
SAPHIR
L1
N
230 VAC 50/60 Hz
24 VAC
2 AT
Figure 8: Transformer connection
A supply voltage > 29 VAC can destroy the unit!
The power supply of the SAPHIR unit must not be grounded!
Transformer data
Primary voltage: 230 V
Secondary voltage: 24 V
Power: 15 VA
Secondary protection: 2 A, slow
Primary side protection can be provided by a motor circuit-breaker or circuit breaker
terminal.
Supply voltage: 24 VAC, ±15%, 50/60 Hz or
Electrical values
26 V...35 VDC
Current consumption: approx. 0.3 A with full configuration
The cross-section of the connecting wires should not exceed 1.5 mm² because of the
Cage Clamp terminals.
Cables
The SAPHIR housing is grounded at the central earth connection point via a mounting
lug with a conductor cross-section > 10 mm² (copper conductor).
Grounding
The transformer must not be used to supply any additional devices other than the
SAPHIR unit (e.g. control valves, damper actuators etc).
Any other necessary supply voltages are generated via rectifiers and DC/DC converters
in the device. The supply voltages for the microcontroller are monitored via the
software.
The supply voltage low limit is monitored via a comparator. If it falls below the tolerance
of -15 %, an NMI is generated in the controller.
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Siemens Building Technologies Hardware Description CE2P3689en
HVAC Products Hardware 25.11.2004