Siemens 7VV3003-5AG32, Руководство по эксплуатации

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3 - Description 04.05
10 ENGLISH
Siemens AG 7VV3003-8TA74
SICROWBAR 7VV3003 DC-Surge Suppressor Operating Instructions
Monitoring Function
Voltage Sensing Module for Field Discharge/Discharge Resistor
The voltage sensing module for the field discharge/discharge resistor 6QM1350 is connected to bar
C via a series resistor and to the external field discharge/discharge resistor via terminal XEW1. The
voltage sensing module transmits the current to the electronics to ground potential by means of an
optocoupler. The output bit at terminal 34 switches to LOW when a certain voltage level is reached
(refer to the device data for details). The output bit at terminal 35 is set to HIGH. When voltage
sensing is activated, the supplying converter must be blocked and the current reduced to zero. It is
not, however, possible here to determine whether the holding current has been undershot and the
thyristor turned off as a result. Likewise, monitoring is not possible if the external line XEW1 from
the field discharge/discharge resistor is interrupted. The module requires an external 24 V DC
power supply with at least 100mA.
Field discharge/discharge resistor
The field discharge/discharge resistor is an external device. Its resistance must be small enough so
that the voltage remains below the destruction limit for the supplying converter even when the load
current is at its highest. The lowest possible resistance value is determined by means of the supply
voltage and the maximum load current of the converter (fuse rating).
3.4 Selecting a Suitable SICROWBAR and Notes on Dimensioning
(incl. Options)
The configuration comprises a SICROWBAR DC surge suppressor and a field discharge/discharge
resistor. No information is provided here on dimensioning this resistor.
The following device parameters must be determined in order to select the appropriate device:
1. Igniting voltage U
BOD
: when this voltage is reached, the SICROWBAR thyristors are turned on.
2. The maximum current that occurs (temporary I
S
and continuous I
D
)
Re 1. Igniting voltage U
BOD
:
2.1 U
AN
< U
Ign
< U_limiting voltage
U
AN
is the line-side supply voltage (AC) of the excitation equipment.
U_limiting voltage is the maximum thyristor blocking voltage or the maximum permissible voltage at
the field coil (whichever of the two values is the smaller).
U
Ign
is the threshold voltage on the SICROWBAR rating plate
The values in the following table apply if a SIMOREG DC master is used:
Input voltage 3AC Limiting voltage DC Selected U
Ign
Permissible I
D
460V, 575V 1500V 1200V 1300A
690V 1700V 1600V 1300A
< 830V 2100V 1600V 1300A
If a SIMOREG DC master is not used, the values of the selected thyristors and field coil must be
used.