Table of Contents
Advertisement
Installation, wiring, commissioning
3.3 Connecting
3.3
Connecting
Safety Extra-Low Voltage (SELV) by a Limited Power Source (LPS)
The equipment is designed for operation with Safety Extra-Low Voltage (SELV) by a
Limited Power Source (LPS).
This means that only SELV / LPS complying with IEC 60950-1 / EN 60950-1 / VDE 0805-1
must be connected to the power supply terminals. The power supply unit for the device
must meet NEC Class 2 according to the National Electrical Code (r) (ANSI / NFPA 70).
If the equipment is connected to a redundant power supply (two separate power supplies),
both must meet these requirements.
NOTICE
Suitable fusing for the power supply cables (corresponds to "Limited Energy")
The current on the terminal must not exceed 3 A. Use a fuse for the power supply that
protects against currents > 3 A.
The fuse has to be designed for protection of DC power supply circuits as well as for the
following requirements.
• In areas subject to the NEC or CEC, the fuse must meet the following requirements:
• In other areas:
If the properties of the supplying current source are known, the following fuse is also
possible:
● In areas subject to the NEC or CEC, the fuse must meet the following requirements:
– Suitable for DC (min. 60 V / max. 3 A)
– Breaking current > highest possible current of the current source (incl. short circuit
– Approval in accordance with UL 1077 or CSA C22.2 No. 235
40
WARNING
– Suitable for DC (min. 60 V / max. 3 A)
– Breaking current min. 10 kA
– UL/CSA listet (UL 248-1 / CSA 22.2 No. 248.1)
– Classes R, J, L, T or CC
– Suitable for DC (min. 60 V / max. 3 A)
– Breaking current min. 10 kA
– Approved for power supply circuits (branch circuits) according to local regulations
(e.g. IEC 60127-1, EN 60947-1)
– Breaking characteristics: B or C circuit breakers and fuses
current and fault)
Operating Instructions, 10/2019, C79000-G8976-C503-02
SIMATIC CC7
Advertisement
Table of Contents
