Sices HS 315, Техническое руководство

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182 Technical Handbook
If the current rises above the threshold, the protection activates with a time inversely
proportional to the overcurrent. To correctly set the thresholds, perform the following steps:
•
Set the maximum current threshold with the parameter P.0309, as a percentage of the
rated current (P.9502).
•
Set the action time in the parameter P.0310: the protection will be activated exactly
after this time if the current is constantly equal to the threshold P.0309 multiplied by
2
, in a shorter time if the current is higher; in a longer time if the current is lower;
and it will never do if the current is lower than P.0309.
To calculate the intervention time for a set current, please use the following formula:
1
309 .
310 .
2
−






=
P
I
P
t
I
Where
I
is the current in the circuit.
Please remember that the protection acts by performing the integral of the current value during
time; therefore, current values above the rated threshold all concur to define the intervention
time, with their instant weight resulting from the above formula. Thus, the only way to
experimentally verify this formula is to switch instantaneously from a normal load situation to
an overload situation.
The following graph shows the curve used for enabling protection, with a value of P.0310 set
to 60 seconds (I is the maximum current):
This protection is only enabled if the engine has been started by the controller (if the command
for the fuel solenoid is activated) and it is disabled during the crank/stop cycles. Type is
configurable with parameter P.0323 (though it cannot be configured as warning).
Type: Alarm
Related parameters: P.0495 Keyboard options.
0,1
1
10
100
1000
1 10
R
e
a
c
ti
o
n
t
ime
i
n
s
e
c
o
n
d
s
I multiples
Trip time
Tempo
intervento