Siemens SINAMICS DCM Operating Instructions Manual page 598

Descriptions of functions
10.32 Diagnostics
Selecting thyristor diagnostics
Thyristor diagnostics are performed during the switch-on procedure. Parameter p50830 can
be used to select for which switch-on procedures thyristor diagnostics is performed.
p50830
Thyristor diagnostics sequence
At each switch-on procedure, starting from operating state o7 the drive goes into state o0.
During thyristor diagnostics, it remains in operating state o3 (see parameter r50000).
Thyristor diagnostics takes approx. 30 s.
Thyristor diagnostics comprises two parts:
1. Checking the thyristor for its blocking capability
All thyristors are individually fired and it is not permissible for current to flow. If it does,
this indicates that a thyristor is fused or it triggers with forward breakover or a ground fault
has occurred, i.e. terminal 1C or 1D is connected to ground.
596
= 0 never
= 1 at the first ON after switching-on the electronics
= 2 at each ON
= 3 at the next ON (p50830 is then reset to 0)
NOTICE
Ground leakage circuit breaker
In IT systems (i.e. in systems with an ungrounded neutral point of the supply
transformer), the thyristor diagnostics cannot detect a single-pole ground fault.
For these types of line supply, it is recommended that a ground fault monitor is used.
WARNING
Electric shock or electric arc during operation with ground fault
The type and location of the fault cannot be established just from a ground fault error
message. In the event of continued operation, serious aftereffects all the way to electric
arcs are possible. This can result in death, serious injury or material damage.
• If a ground fault occurs during operation, the system must be switched off
immediately. Then identify and eliminate the source of the ground fault.
• The plant operating company is responsible for the consequences for further
operation after a ground fault has been detected. Carry out a risk analysis.
SINAMICS DCM Control Module
Operating Instructions, 12/2018, A5E34888669A