Last section of the characteristic:
If
VDepMode
= either
Slope
or
Step
, the minimum measured phase-to-phase
voltage is higher than
UHighLimit
/100*
UBase
:
•
UL1: Ampl = 105/ √3; Angle = 0°
•
UL2: Ampl = 105/ √3; Angle = 240°
•
UL3: Ampl = 105 / √3; Angle = 120°
4.
Inject the voltages that are related to the first part of the characteristic, and then
slowly increase the phase current IL1 from 0.0 A up to the value the function
operates. The START and STOC signals must be activated when the amplitude
of the phase current IL1 is slightly above 0.25 A on the secondary side. The
corresponding trip signals TROC and TRIP will be activated after the pre-set
time delay has expired.
5.
Decrease the current IL1 slowly and note the reset value.
6.
Repeat steps 4 and 5 applying voltages that are related to the second and the last
section of the characteristic; the function operates when IL1 is slightly higher
than: 0.5 A in the second section; 1A in the last section.
7.
Connect the trip output contact to the input channel of the test set in order to stop
the injection and measure the trip time.
8.
If definite time delay is used for the overcurrent step, set the setting
Characterist
=
IEC Def. Time
. Apply the voltages related to the last part of the characteristic
and inject a current IL1 200% higher than the set operation level, and check the
definite time delay for trip (the signals TROC and TRIP of the protection
function VRPVOC are active in trip condition).
9.
If inverse time delay is used for the overcurrent step, the parameter setting
Characterist
shall be properly set; we can refer, for example, to the setting
IEC
Very inv.
; If the IEC Very inverse time characteristic is selected, the trip signals
TROC and TRIP will operate after a time defined by the equation:
t s
k
I
StartCurr
[ ]
=
−
13 5
1
. *
IECEQUATION2435 V1 EN
(Equation 18)
where:
t
Operate time in seconds
I
Measured value (for example, phase current)
StartCurr Set operate value
This means that if the measured phase current jumps from 0 to 2 times the set
operate level and time multiplier k is set to 1.0 s (default value), then the TROC
and TRIP signals will operate after a time delay equal to 13.5 s ± tolerance.
Taking into account the above explanation, inject the voltages related to the last
part of the characteristic and inject a current IL1 200% higher than the set
operation level, and check the trip time delay.
Section 10
1MRK 511 360-UEN A
Testing functionality by secondary injection
116
Bay control REC670 2.1 IEC
Commissioning manual
