Fuse And Electronic Overload Protection - Siemens SIMATIC S7 Functional Safety Manual

Technical specifications
A.3 Fail-Safe signal module (SM) technical specifications
Model
Switching frequency:
With resistive load
•
With inductive load in accordance with IEC 60947-5-1,
•
DC13
With lamp load
•
Cable length (meters)
Reverse polarity protection
A.3.3.4

Fuse and electronic overload protection

Overload protection attempts to protect the module from damage from moderate faults in the
range of 2.4 A to 15 A at the P switch. Above 15 A on each P-switch fuse, the internal non-
replaceable fuse can open. Supply your SM 1226 F-DQ 4 x 24 VDC from a source limited to
less than 15 A, or use an external fuse or non-shorting load element to prevent opening of
the internal fuse.
The internal electronic limiting causes the channel to passivate and reports as an overload. If
no damage results, you can reintegrate the channel after removal of the external fault.
180
SM 1226 F-DQ 4 x 24 VDC
30 Hz symmetrical, maximum
0.1 Hz symmetrical, maximum
10 Hz symmetrical, maximum
200 m unshielded
•
200 m shielded
•
Yes, except loads connected between M-switch and L+ will
conduct if M and L+ are reversed.
Note: Refer to Digital Output Application Mode 2 (Page 76)
for more information.
S7-1200 Functional Safety Manual
Manual, 02/2015, A5E03470344-AA