Functional Software description
66
DCS 500 Software Description
When the level is adjusted, the signal
I TRIP A
is updated auto-
matically.
Note.
With converter type C4 the nominal values must be given to
the program with parameters 517...521.
When the overcurrent limit is exceeded, an OVERCURRENT-fault
will appear (fault code 2).
Over -
temperature
The maximum temperature of the bridge can be read out from signal
MAX BR TEMP (10512)
, scale: 1 = 1
°
C. If this limit is exceeded, a
CONVERTER OVERTEMP-fault will occur. The alarm limit is 10
°
C
below the tripping limit. Actual bridge temperature is given by signal
BRIDGE TEMP (10507)
, (scale 1 = 1
°
C).
With converter type C4 the maximum temperature of the bridge
must be given to the program with parameter 519.
Earth Fault
Earth fault indication is based on a sum current transformer in the
supply. The sum of three phase currents is zero, if there is no earth
current.
M
A
D
SUPPLY
Delay
t
0
COMP
EARTH.FLT LEV
EARTH.CUR SEL
Earth
fault
I1 > I2
EARTH.FLT DLY
Figure
46
Principle of earth fault current measurement
Earth fault protection is activated by parameter
EARTH.CUR SEL (514)
.
0 = not used
1 = activated
Earth fault current tripping level is defined by parameter
EARTH.FLT LEV (515)
.
(scaling in amps)
The time after which fault is activated is defined by parameter
EARTH.FLT DLY (516)
.
(scaling 0.001s)
Summary of Contents for DCS 500B
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