Page 77
Possible reasons:
a) the charging resistance is opened.
b) The charging circuit has a failure.
c) There is a problem in the power section.
8. MAIN CONTACTOR ALARMS
COIL SHORTED:
When the key is switched ON the µController checks the LC coil driver shortcircuit
protection hardware. If it does not react in a correct way to the µC stimulus, the alarm is
signalled. Replace the logic board. When the fault occurs while the LC is closed, the
alarm signals a shortcircuit across LC coil.
Check if there are external shortcircuit and if the ohmic value of the MC coil is correct;
otherwise replace the logic.
DRIVER SHORTED:
When the key is switched ON, the µC checks that the LC coil driver is not shorted; if it
is, this alarm is signalled. Preliminary, check if there is an external short or low imped-
ance pull-down between NLC (C26) and -BATT. If no external causes can be found out,
replace the controller.
CONTACTOR DRIVER:
When the initial diagnosis is finished, the traction logic closes the LC and checks the
voltage on the Drain of the driver. If this is not low , the driver is not able to close an
alarm is signalled. Replace the logic.
CONTACTOR OPEN:
The main contactor coil has been driven by the logic board, but the contactor does not
close. Two possible reasons:
a) the wires to the coil are interrupted or not well connected.
b) the contact of the contactor is not properly working (does not pull-in).
CONTACTOR CLOSED:
Before driving the LC coil, the controller checks if the LC contact is stuck. The controller
drives the bridge for a while, trying to discharge the capacitor bank. If they don't dis-
charge, the fault condition is entered. It is suggested to check the contactor contact, if it
is mechanically stuck.
9. ENCODER ERROR
This alarm is signalled in following condition: the frequency supplied to the motor is
higher than 20 Hz, and the signal feedback from the encoder has a jump higher than 20
Hz in few tens millisecond. This condition clearly shows a malfunctioning of the encoder
signal. It is suggested to preliminary check the encoder wiring; if no fault is found in the
wiring it is necessary to replace the encoder.
To Next Page
Loading...
Need help?
General
