Cold Load Pickup Settings Menu - DEMA CPM 310 G User Manual

Cold Load Pickup Settings Menu

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Cold Load Pickup
Cold Load Pickup (CLP) feature of CPM 310 G provides
the option to pull up delay times of desired protection
functions to enable easy pickup of machines and
systems with high pickup / inrush current without
protection relay intervention.
The cold load pickup operation starts when a
programmable input with
receives a signal. Once the CLP function is active, delay
times for the configured functions are multiplied by the
Level
parameter for the time determined by the
parameter. Initialization by the
input can be achieved by cabling the input terminals to
a normally open auxiliary contact terminals of the
Application Diagram 1
circuit breaker. See
this manual on the subject.
In order to utilize the cold load pickup function, one of
any programmable inputs should be programmed as
"Start CLP" and one of the normally open contacts of
the circuit breaker should be wired to that input. Once
these arrangements are complete,
function will start to operate to modify the protection
levels ONLY at the moment the circuit breaker is
closed, but not for disturbances that occur during
stable operating conditions.
The following scenario examines CPM 310 G's cold load
pickup behavior:
 Let the relay be set to I>> = 1.00 I
SI and TMS = 1.00.
 Cold Load Pickup function is set as "Active", Level =
%200, Time = 1.00 s and I>> = Active.
 At the moment the circuit breaker is closed ("Start
CLP" input is activated) the I>> threshold will be
temporarily set to 2.00 I
Please pay attention to the following characteristics of
the function:
 If any of the protection functions that is controlled by
the Cold Load Pickup function has DMT delay
characteristics, CLP will only modify the threshold
value, but not the trip delay time.
 If any of the protection functions that is controlled by
the Cold Load Pickup function has IDMT delay
characteristics, CLP will modify both the threshold value
and the trip curve characteristics. For the scenario
above, if a current of 3 I
CLP time; the ratio of (I/I
Level
instead of 3.0, as the
Consequently, trip delay will be longer than normal. ↺
- 103 -
Start CLP
appointment
Start CLP
appointed
at p.194 of
Cold Load Pickup
, DType = IEC
n
instead of 1.00 I .
n n
is measured within the active
n
) will be treated as 1.5
s
parameter is set to %200.
Time