Siemens SIMATIC S7-400 Reference Manual page 50

Power supply modules
3.5 Fault/Error messages via LEDs
INTF
LED
D
D = LED is dark; H = LED lights up; B = LED flashing;
* If the power supply module does not start up again after a few seconds once the overload
has been removed, remove power to the module for 5 minutes and then switch it on again. If
the module stills does not start up, you must replace it. This applies to the following power
supply modules:
● 6ES7407-0KA01-0AA0, Release 3
● 6ES7407-0KR00-0AA0, Release ≤ 5
● 6ES7407-0KA01-0AA0, Release ≥ 10
● 6ES7405-0DA02-0AA0, 6ES7407-0DA02-0AA0
● 6ES7405-0KA02-0AA0, 6ES7407-0KA02-0AA0
● 6ES7405-0KR02-0AA0, 6ES7407-0KR02-0AA0
● 6ES7405-0RA02-0AA0, 6ES7407-0RA02-0AA0
The same characteristic is displayed by the built-in overtemperature protection is triggered.
If either the 5 VDC or 24 VDC LEDs remains dark after switching on, the system has not
powered up.
If either of the 5 VDC or 24 VDC LEDs of the PS 407 10AR remains dark for longer than 1 or
2 seconds after it is switched on, the power supply module will not start up.
The following power supply modules will switch off in the event of a short-circuit or overload
after 1 to 3 seconds. The module will try to restart after no more than 3 seconds. If the error
has been eliminated by then, the module will start up. This applies to the following modules:
PS 405 4A (6ES7405-0DA01-0AA0)
PS 405 4A (6ES7405-0DA02-0AA0)
PS 405 10A (6ES7405-0KA01-0AA0)
PS 405 10A (6ES7405-0KA02-0AA0)
PS 405 10A R (6ES7405-0KR00-0AA0)
PS 405 10A R (6ES7405-0KR02-0AA0)
PS 405 20A (6ES7405-0RA01-0AA0)
PS 405 20A (6ES7405-0RA02-0AA0)
50
LED LED
DC5V DC24V
B B Dynamic overload on 5 V and 24 V
Modules
Cause of fault
PS 407 4A (6ES7407-0DA01-0AA0)
PS 407 4A (6ES7407-0DA02-0AA0)
PS 407 10A (6ES7407-0KA01-0AA0),
release ≥5
PS 407 10A (6ES7407-0KA02-0AA0)
PS 407 10A R (6ES7407-0KR00-0AA0),
release ≥7
PS 407 10A R (6ES7407-0KR02-0AA0)
PS 407 20A (6ES7407-0RA01-0AA0)
PS 407 20A (6ES7407-0RA02-0AA0)
S7-400 Automation System Module Data
Reference Manual, Ausgabe 11/2016, A5E00850736-08
Remedy
Check load on the power supply
module. Possibly remove mod‐
ules.