Dead Bus Start

A close CB command without synchronization may be issued if the following

conditions are fulfilled simulta neously:

• Dead bus start function is configured to ON (Parameter 43).

• Discrete input “Enable CB” is set.

• Discrete input “Reply: CB is open” is set.

• One of the three possible black start functions is enabled

1.) Parameter 46 (Vsystem A=Vn/Vsystem B=0)

Vsystem A is equal with Vn (using the configured rated voltage difference dV

|V-Vn|) and Vsystem B is zero (using the configured zero voltage difference

dV |V-0|).

2.) Parameter 45 (Vsystem A=0/Vsystem B=Vn)

Vsystem A is zero (using the configured zero voltage difference Vd |V-0|) and

Vsystem B is equal with Vn (us

ing the configured rated voltage difference dV |V-Vn|).

3.) Parameter 44 (Vsystem A=0/Vsystem B=0)

VA is zero and VB is zero (using the configured zero voltage difference dV |V-0|).

• No alarm is triggered if parameter “Blocking at dead start alarm” is configured

to ON (Parameter 51).

• No GCP is trying to carry out a dead bus start.

• No higher prioritized LS 4 is trying to close its breaker.