Nortel DMS-100 Series Maintenance Manual page 75

marked failed, determine if string 1, 5, or both caused the alarm. For
OPMs with an MTU, the default for OPM_VOLT_TST_DIS = -495 or
-49.5V dc for Yuasa and Eagle-Picher batteries. For OPMs with an LTU,
the default for OPM_VOL_TST_CHG is offset by
OPM_VOLT_TST_LTU ADJUSTMENT (default=10) and truncated
(-495+10 = -485 Trunc(-485) = -480 or -48V dc for Yuasa and
Eagle-Picher batteries.
8. Open circuit the failed battery string pair. Go to step Item 9, "Disable the
AUDIT from the PES MAP level." on page 1-59.
9. Disable the AUDIT from the PES MAP level.
10. To determine which voltage of the battery string tested below
OPM_VOLT_TST_CHG, use the PES117 log. If strings 1 and 5 were
marked failed, determine if string 1, 5, or both caused the alarm.
For OPMs with an MTU, the default for OPM_VOLT_TST_CHG = -509
or -50.9V dc for Yuasa and Eagle-Picher batteries. For OPMs with an
LTU, the default for OPM_VOL_TST_CHG is offset by
OPM_VOLT_TST_LTU_ ADJUSTMENT (default=10) and truncated
(-509+10=-499 Trunc(-499)=-490 or -49V dc for Yuasa and Eagle-Picher
batteries.
11. From the PES MAP level place the failed battery string pair on the charge
bus for 6 h.
12. Open circuit the failed battery string pair for a minimum of 6 h.
13. Use the PES MAP level MEASURE command to measure the voltage of
the failed battery string pair.
14. If the voltage is less negative than OPM_VOLT_TST_CHG, leave the
battery string pair open circuit and proceed with OPM site tests.
15. If the voltage is equal to or more negative than OPM_VOLT_TST_CHG,
the string can continue to accept a charge. Apply the BSY and RTS
commands to the BCCDVR to return the battery string pair to service.
The same string can be failed by the post-charge test within the next two
months. If this failure occurs, proceed directly to OPM site tests.
OPM site tests
Proceed as follows to perform OPM site tests:
1. Disable the AUDIT. Open-circuit the failed battery string pair from the
PES MAP level.
2. Proceed to the OPM site to perform the following steps.
3. Use a voltmeter with a maximum of 0.2% error to measure the voltage of
both rectifiers. Connect the voltmeter to the test jacks on the rear of the
rectifiers.
DMS-100 Family OPM Maintenance Manual ISN07 (TDM)/SN07 (DMS) and up
OPM maintenance summary 1-59