RP01 / Chapter 1
115 804 2401.0304
Page 13
Service Training
03.04
Section 6
6.1.5 INTERMEDIATE CIRCUIT CAPACITORS, SWITCHING ON AND CHARGING
The intermediate circuit capacitors are located inside the main traction/hydraulic power unit 1A1. In order
to prevent very high current flowing across the contact tips of K1, capacitors are pre-charged before K1
energises.
This pre-charging is carried out via a charging circuit using two relays K2 and K3. When the keyswitch
is turned on, the relay K3 is activated directly by voltage transformer U1. The relay K2 is directly activated
by the drive electronics within 1A2. As soon as the two relays are activated, the capacitors in the power
unit can charge up via the charging resistor R1.
Only when the intermediate circuit capacitors are charged can the activation of the main contactor K1 take
place (monitored by an electronic circuit inside 1A2). Approximately five seconds after that, the relay K2
is switched off again, since the capacitors are now receiving their charging voltage via the contacts of the
main current contactor K1.
R1
X12:2
BKOG
K3
K2
R2
X12:3
X12:1
GN
WH
GY
BU
R3
X12:4
BKBN
To Next Page
Loading...
