Komatsu 960E-1 -, Руководство по ремонту, Страница: 46 / 51

CEN00002-05 00 Index and foreword
28
Failure of the discharge system
If the capacitor charge lights remain illuminated, a
failure of the normal (fast) capacitor discharge
system (RP discharge path) has likely occurred. The
slow discharge resistors that are hard wired across
the DC link should then discharge the capacitors. The
slow discharge resistors will discharge the DC link to
less than 1 VDC in under 7.5 minutes. If after 7.5
minutes, the capacitor charge lights are still
illuminated, it must be assumed that the automatic
discharge system is not working and that high voltage
is present in the high voltage area.
1. Open the high voltage area doors.
2. With a suitable high voltage meter rated for at
least 2000 VDC, such as PC3186 or equivalent,
plus suitable protective equipment, measure the
voltage across each of the DC link capacitors.
Place one meter lead on the positive (+)
capacitor terminal, and the other meter lead on
the negative (-) capacitor terminal, and observe
the voltage. See Figure 00-7 and Figure 00-8. If
the voltage is less than 1.0 V the capacitor is
sufficiently discharged. Repeat on all DC Link
capacitors. If the voltage of any capacitor is
above 1.0 V, manually discharge the capacitor
as described in "Manual discharge of
capacitors".
FIGURE 00-7. DC METER ON CAPACITOR
FIGURE 00-8. CAPACITOR TERMINAL POLARITY