Areva MiCOM P225, Technical Manual

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User Guide P225/EN FT/B11
MiCOM P225 Page 29/52
4.11 The AUTOMAT. CTRL menu
The AUTOMAT. CTRL menu comprises the following 14 sub-menus:
•
[66] START NUMBER
•
MIN TIME BETW 2 START
•
RE-ACCEL AUTHORIZ
•
INPUTS
•
AND LOGIC EQUATION
•
AND LOGIC EQUAT T DELAY
•
AUX OUTPUT RLY
•
LATCH AUX RLY
•
TRIP OUTPUT RLY
•
LATCH TRIP ORDER
•
CB FAIL
•
ABS
•
BUS VOLTAGE CTRL
•
CB SUPERVISION
4.11.1 The [66] START NUMBER submenu : Limitation of the number of starts per period
The [66] START NUMBER function allows the number of motor start-ups over a given period
to be limited. In effect, starting the motor too frequently can be too constraining for the motor
(over-heating), for its starting system (starting impedance, electrolytic bath,...) or can in some
cases reveal an anomaly in the process operation,
The [66] START NUMBER function uses the following adjustable parameters.
−
a monitoring period T
reference
−
a number of hot starts limit HOT START NB
−
a number of cold starts limit COLD START NB
−
a start inhibit time delay T
interdiction
.
Each time an motor start is detected, the T
reference
time delay is initiated and the number of
starts registered by the counter corresponding to the temperature of the motor (hot or cold) is
incremented by one. At the end of this time delay, the counter in question will be
decremented by one.
Each time the motor is stopped (change of state of logic input L1: from state 1 to state 0)
relay P225 establishes whether either of the two counters has been reached. If so, start
inhibit signal START NB LIMIT will be generated for a length of time equal to T
interdiction
. At the
end of T
interdiction
, this signal drops out, and it is possible to start the motor again.
Examples: Taking as an example cold starts where the limit of the number of cold starts
has been set at 3 for a period of T
reference
.