
MEP 660 - Trouble shooting Manual
Doc No.: IM – 51
Rev.2.0
Print: October 2008
127
valve coil terminal (Cable ID: AY, Pin-A). If necessary replace
the cable.
C. If the continuity is good and there is no slackness in connector,
then the digital output card MLSD 16 in slot No. 14 is defective.
Replace the card.
11. If P1 is picking up, check the status of Green LED 3 on the digital
input card 2 in slot 10.
12. If the Green LED 3 is not glowing, check supply Voltage at auxiliary
contact (wire No. 51) with respect to locomotive 4 wire.
A. If voltage is zero, check the continuity of 51-wire loop coming to
P1 power contactor auxiliary contact.
13. If voltage is more than 65V, then check voltage at auxiliary contact
(wire no. P1FB) with respect to locomotive 4 wire.
A. If voltage is zero, the auxiliary contact is bad. Replace the
auxiliary contacts.
14. If voltage is more than 60 V,
A. Check the slackness of connector of cable ID: AU at MEP-660. If
slack tighten and check the LED status.
B. Check the continuity of Wire P1FB from P1 power contactor to
MEP-660. (Cable ID: AU, Pin-D). If necessary replace the cable.
15. If the Green LED 3 is glowing:
A. Check the status of corresponding Yellow LED on the same card.
B. If the yellow LED is not glowing, then the digital input card MDIP
16 in slot No. 10 is defective. Replace the card and check.
16. If Both Green and Yellow LEDs 3 are glowing on the digital input
card MDIP 16 in slot 10, the feed back status should be displayed
ON. Toggle the P1 contactor operation two to three times and
ensure the feedback signal is changing accordingly.