ABB ACS 1013-A1, User Manual

Page: 39 / 186

03 POWER ELECTRONICS AND CABINET FEATURES
3BHS213401 E01 REV H ACS1000 AIR-COOLED USER MANUAL 37/184
3.4.4 Grounding switch
The grounding switch is a safety device that enables safe access to the medium voltage
compartments of the drive.
When the switch is in position grounded, the DC link of the drive is connected to the PE
ground busbar.
The grounding switch is electro-mechanically interlocked with a discharge monitoring circuit
that prevents closing of the switch while the DC link capacitors are still charged.
Grounding the drive is only possible after the main power supply has been disconnected, and
the DC link has discharged. When the voltage is below 50 V (DC), the lamp grounding switch
unlocked (1 in Fig. 3-7) on the door of the control compartment lights up, and the grounding
switch can be turned to position grounded (2 in Fig. 3-7).
Figure 3-7: Grounding switch
When the grounding switch is in position grounded, the doors of the medium voltage
compartments are released, and the doors can be opened.
3.4.5 Rectifier
The diode rectifier converts the AC voltage of the main power supply and connects its output
to the minus, neutral point, and plus side of the DC link.
Depending on the harmonics requirements for the main power supply, the drive is equipped
with a 12-pulse or a 24-pulse rectifier.
3.4.6 Protection IGCTs
The drive features a fuseless protection design. The IGCTs are placed between the rectifier and
the DC link. If necessary, the IGCTs directly isolate the inverter from the main power supply.
(1) Grounding switch unlocked lamp is on (2) Grounding switch in grounded position
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