EP Equipment CQD16, Service Manual

Page: 149 / 251

REV. 07/2016
ELECTRICAL SYSYTEM
8
135
Error Message
Possible cause Fault elimination
CHECK UP
NEEDED
This is a warning. It is an information for
the user that the programmed time for
maintenance is elapsed.
MAIN CONTACTOR
ALARMS
- COIL SHORTED
When the key is switched ON the
μ P
checks the MC driver FF SR. If it does not
react in a correct way to the
μ P stimulus,
the alarm is signalled. Replace the logic
board. The FF SR makes an hardware
control of the current in the MC coil. If this
is too high, it opens the MC and the alarm
is Signalled. Check if there are external
shortcircuit and if the ohmic value of the
MC is correct; otherwise replace the logic.
- DRIVER SHORTED
When the key is switched ON, the
μ P
checks that the MC coil driver is not
shorted; if it is, this alarm is signalled;
replace the logic board.
- CONTACTOR DRIVER
When the initial diagnosis is
fi nished, the
traction logic closes the MC and checks
the voltage on the Drain of the driver. If
this is not low, 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.
- CONTACTOR CLOSED
The controller checks if the LC contact is
closed when the coil isn’t driven, trying to
discharge the capacitor bank. If they don’t
discharge, the fault condition is entered.
It is suggested to check the contactor
contact, if it is mechanically stuck or
pasted.
T r o u b l e s h o o t i n g , t h e a l a r m i s
eliminated.
AUX OUTPUT KO
T h e μ P c h e c k s t h e d r i v e r o f t h e
electromechanical brake. If the status of
the driver output does not correspond to
the signal coming from the
μ P, the
alarm is signalled.
if the default persists, replace the logic.