Total Current Monitoring; Fault Current Monitoring - Siemens SIPLUS HCS Series Operating Instructions Manual

Functions
9.7 Monitoring functions
9.7.9

Total current monitoring

Channel total current
The aggregate current per power output is monitored. If the measured current is above the
permitted operating range in normal operation (not startup after heating on), an error
message "current load too high" is issued. The output can still be controlled, however.
Phase total current
The aggregate current over all power outputs of a phase is monitored. If the measured
current is above the permitted operating range in normal operation (not startup after heating
on), an error message "phase current too high" is issued. The outputs of the phase in
question are still controlled.
9.7.10

Fault current monitoring

Any current which does not flow across the load connections, but rather irregularly over
another path (e.g. via the housing of the load), is referred to as fault current.
Fault current is monitored for connection type "2-pin switching" via a channel pair. The
threshold is set for each channel. In case the configured threshold is exceeded, an error
message is generated; however, this does not result in switch-off of the output. Heating
remains possible.
Conditions for secure control of the channels
NOTICE
Physical damage can occur
If the electric resistance through which the fault current flows exceeds twice the electric
resistance of the load, the corresponding channel can no longer be correctly controlled.
Therefore comply with the following condition for secure control of the channel:
R
fault
152
> 2 • R
load
SIPLUS HCS4200 PROFINET/PROFIBUS DP
Operating Instructions, 07/2019, A5E35066204A/006