RECLOSER CONTROL EVRC2A-N6,NT http://www.entecene.co.kr
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TECHNOLOGY
7.12. Cold Load Pickup
The cold load pickup function is used to prevent the recloser from incorrectly operating caused
by the restoration of load supply or the cold load current of load side. EVRC2A provides
“CLPU-Type 1” to prevent the recloser from operating wrong by instantaneous inrush current
occurring by the closing of device on a power line and “CLPU-Type 2” to prevent protection
elements from operating wrong by the cold load current caused by applying voltage to a
transformer, a reactor or a long-distance line.
7.12.1. Cold Load Pickup – Type 1
The settings of “CLPU-Type 1” are separated and set respectively for phase, ground, SEF or
negative phase over current element.
In the state of the function to restrain the inrush current activated, the overcurrent protection
element will be operated under settings of “CLPU-Type 1” function at the restoration of load
supply.
NOTE:
According to setting of “Make use ‘I’”, the condition to decide the restoration of load supply will
be changed. If “YES” is set, the decision is made when the load current becomes over 2A. If
“NO” is set, the decision is made when a recloser is closed (52A) by local or remote control.
When a distributed system is closed after long-time outage, the inrush current over overcurrent
pickup level may occur. At occurrence of the cold load pickup, EVRC2A increases the pickup
level of overcurrent element during a certain period of time, the Fast overcurrent protection
element is not operated and the Delay overcurrent protection element is always operated
regardless of the cold load pickup function. (The High Current Trip and High Current Lockout
are always operated regardless of the cold load pickup function)
If a fault occurs on distributed system, an overcurrent protection element is operated by the cold
load pickup function and a recloser becomes lockout after oneshot trip regardless of total number
of shots.
A power is lost and then after certain outage time, the algorithm of cold load pickup function is
applied at the restoration of load supply. If the “Make use ‘1’” is set to be “YES”, the algorithm
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