Baumuller b maxx BM4400, Инструкция по эксплуатации

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Operation
Instruction handbook b maXX BM4400, BM4600, BM4700
Document No.: 5.12008.07
225
of 358
8
8.3 Power on switching frequency / DC link charging
8.3.1 Power supply switch-on frequency BM441X and BM442X
The devices use a rectifier with 6 diodes (B6U circuit). There is a resistor between rectifier
and DC link capacitor limiting the charging surge. The resistor is bridged by a relay after
the charging. Smaller waiting periods between the DC link discharge and charge reduce
the lifetime of the devices. The specified waiting time of the device is increased to at least
90 seconds when an additional external DC link capacity is connected. The maximum
permitted external DC link capacity depends on the power supply voltage (see
Z Figure
32 – on page 65 or Z Figure 34 – on page 69).
8.3.2 Power supply switch-on frequency BM443X (Generation 1)
Refer to Z Explanation version code – on page 130.
The devices use a rectifier with 3 diodes and 3 thyristors (B6HK circuit). From the voltage
on the thyristors a sawtooth shaped voltage with power supply frequency is generated.
This synchronous voltage is compared with a voltage decreasing from a start value to 0 V
within ca. 10 seconds. If the current values of both voltages are equal, a thyristor is turned
on and current flows from power supply to the DC link capacitor.
The maximum chargeable total capacity is limited by the power rating of the thyristors and
diodes to 20 mF.
The thyristors are fired if the DC link charge is finished and a voltage drops in reverse di-
rection on the thyristors.
When using the recommended fuses the rectifier is protected against overcurrent de-
struction.
When observing the limits of amplitude and frequency of power supply voltage and the
value of the external capacity and the mounting of the recommended power choke the
user ensures, that the input rectifier is operated in the permitted operating range.
The phase sequence, meaning clockwise rotating field or counterclockwise rotating field,
is not relevant for charging the DC link and the operation of the device.
Below, the behavior described in the former paragraphs is characterized as „time-con-
trolled charge procedure“.