Siemens SIPROTEC 7SJ62 Instruction Manual page 203

7SJ62 Manual
C53000-G1140-C121-1
If a relay element picks up while the dynamic settings are enabled, elapse of the $F
WLYH 7LPH or 6WRS 7LPH will not restore the normal pickup settings until drop out
of the relay element occurs based on the dynamic settings.
If the dynamic cold load pick-up function is blocked via a binary input, all triggered tim-
ers will be immediately reset and all normal settings will be restored. If blocking occurs
during an on-going fault with dynamic cold load pick-up functions enabled, the timers
of all directional and non-directional overcurrent relay elements will be stopped, and
then restarted based on their normal duration.
During power up of the protective relay with an open circuit breaker, the time delay set
at address  &% 2SHQ 7LPH is started, and is processed using the normal set-
tings. Therefore, when the circuit breaker is closed, the normal settings are effective.
Figure 6-29 shows a timing diagram, Figure 6-30 describes the logic for cold load pick-
up function.
Breaker
Closed
Open
"CB open"-Timer
"CB open"
"Active Time-Timer"
Operating State
"CLP" setting active
"normal setting active"
"Stop Time"-Timer
"Normal"
PickUp Levels
Pickup
Dropout
Figure 6-29 Cold Load Pickup Timing Sequence
"CB open"
increased power consumption
after long outage
Functions
"Active Time"
Possible shorter
CLP, due to
"Stop Time"
"Stop Time"
Trip, if increased
power demand is
present after "Ac-
tive Time" expired
6-63