DEMA CPM 310 G User Manual page 111

CB Failure Settings Menu
Main Screen » Menu »
Automatic Control Settings »
CB Failure Settings
CB Pole Failure Settings Menu
above. Settings to be done on the menu are described below.
CB Failure
This parameter can be set as
Active
. If the parameter is set to
expected CB behavior.
I< (CB Pole Failure Threshold)
This setting is done in I
n
interval of (0.02 – 1.00) I
capability of CPM 310 G, is not recommended to be changed for normal application. Special cases
need further study which will not be discussed here. ↺
CB Pole Failure Settings Menu
function that monitors the primary current value for a
set time after the tripping signal is generated, and
triggers an alarm if the primary current has not
dropped below a set value; which will mean that the
circuit breaker has failed to break the primary circuit as
expected. The alarm signal is displayed on the Alarm
LED and Alarm Menu; an optical or acoustic alarm
signal can be triggered via a programmable output that
the
CB pole failure supervision function can be utilized for
the following functionalities:
 Warning the operator that one or more poles of the
circuit breaker does not operate normally / fail,
 When applicable, blocking the auto-reclosing sessions
if the CB does not break the circuit normally,
 When applicable, eliminating the risk of selectivity
failure on systems where blocking logic selectivity
scheme is utilized. To prevent the situation described
on the latter topic, the normally closed contacts of an
SPDT output that is programmed as
connected in series with the output that generates the
blocking signals; this will prevent the blocking of the
next upstream relay, letting it to clear the fault. This
preventive cabling scheme is given on the previous
page.
controls the parameters of the function and it is seen on the picture
Passive Active
or . To utilize the function, the parameter must be set to
Passive
, the function will not monitor the primary current in means of
(current transformer primary nominal current) and can be set within the
. The default value of 0.02 I
n
CB Pole Failure
option is assigned.
, which is limited by the lowest current reading
n
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controls a supervision
CB Failure
must be