Siemens SINUMERIK MCU1720 Equipment Manual page 67

Note
When connecting an external 24 V DC power supply to the interfaces, it must satisfy the
requirements of a protective extra-low voltage (PELV) according to UL 61800‑5‑1. A series fuse
must also be used that reliably ruptures within 120 seconds at an ambient temperature of 0 °C
for a current of 6.5 A.
Alternatively, a circuit must be used that limits the current to 5 A within 60 seconds during
normal operation and in the event of a single fault.
For a primary supply of the power supply used from OVC III circuits up to 600 V AC (line to
neutral voltage), it must be ensured that the contact gap of the fuse – or the individual fail-safe
circuit – is 3.0 mm according to UL 61800‑5‑1.
When using an external power supply, make sure that the fuse used has a switch-off rating that
corresponds to the maximum possible short-circuit current of the power supply unit used.
Table 8-2
Characteristics
Connector type
Number of cables that can be connected
Connectable cable types and conductor cross-sec‐
tions
Stripped length
Tool
Tightening torque
Max. current carrying capacity, incl. loop-through
Max. cable length
This value must be taken into consideration for the current-carrying capacity of the power supply cable.
*)
The following cable lugs may be used:
● Crimped cable lug to DIN 46234
● Pressed cable lug to DIN 46235
● Tube-type cable lug to SN 71322
● Tube-type cable lug "Klauke R Series", UL Category ZMVV
MCU 1720
Equipment Manual, 09/2019, A5E47437728B AB
X80 interface
Rigid
Flexible
Flexible, with end sleeve without plastic
sleeve
Flexible, with end sleeve with plastic sleeve 1.3 mm² ... 2.5 mm²
AWG/kcmil
Version
2-pole screw-type terminal
1
1.3 mm² ... 2.5 mm²
1.3 mm² ... 2.5 mm²
1.3 mm² ... 2.5 mm²
22 ... 12
6 ... 7 mm
Screwdriver 0.5 x 3 mm (M2.5)
0.5 Nm
20 A (15 A according to UL/CSA)
*)
10 m
Connecting
8.8 Power supply X80
67