Alpha Technologies Cordex Controller Ver.2.0 - Manual (Page 21)

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4.3.4.5 BT Initiation
When the test begins, an entry will be made in the event log. If enabled, an alarm will provide a
warning to indicate that a Battery Test is in progress.
The test will continue, depending on the type of rectifier in use, in accordance with the following
algorithms (as applied to lead acid batteries):
Algorithm 1 — For rectifiers that support Battery Test (BT) mode:
1. A command is sent to put the rectifiers into BT mode.
2. BT mode runs for the period set as Timeout or until BT End Voltage is reached.
Algorithm 2 — For (Pathfinder) rectifiers that do not support BT mode:
1. Rectifiers are commanded to go to nominal voltage.
2. The rectifiers are periodically scanned to be sure that they do not begin sourcing
current. When 3% DOD is reached and the rectifiers are still not sourcing current, the
rectifiers are turned off.
3. The rectifier float setting is reset to the setting stored in the system controller.
4. When the system voltage reaches the end (termination) voltage or a timeout occurs, the
system controller will command the rectifiers to turn ON and enter FL mode.
4.3.4.6 Activity During BT Mode
Temp Comp and Power Save features are suspended during a battery test.
When the battery is discharging, a BOD alarm will be active.
During a test, the mode symbol in the upper left corner of the GUI will be similar to the FL mode
symbol except that the letters “FL” will be replaced with “BT.”
Runtime estimate begins at 3% DOD.
Capacity estimate also begins at 3% DOD, but will not be stored unless DOD > 20%; the point
at which reasonable accuracy can be assured.
4.3.4.7 AC Failure During BT Mode
If the AC fails during a battery test, the test will be aborted. This will place the rectifiers into a
state that will enable them to resume providing power to the load when AC returns. If the
Runtime is being displayed, it will continue to update.
4.3.4.8 Addition of Rectifiers During BT Mode
If rectifiers are added to the system when a battery test is active, they will be placed into the
same state as the other rectifiers. They will be:

Placed into BT mode (for rectifiers that support BT mode), or

Placed into remote shutdown, or

Set to the same voltage as the other rectifiers.
4.3.4.9 Conditions to Watch for During BT Mode
If the voltage drops below 47V before or when 3% DOD is reached, the test is aborted and the
battery capacity is set to 0% (resulting in a Battery Capacity Low alarm). This provides an
indication that the battery is very weak
2 . The battery capacity must be manually reset to 100%,
or to the percentage of expected battery capacity before the next battery test is started, in order
for the battery monitor to again attempt to compute the battery capacity.
If rectifiers are seen to be sourcing current during the test and the battery ceases to be
discharging, the test is aborted.
4.3.4.10 Canceling BT Mode
BT mode can be cancelled by changing mode to FL or EQ.
2 In some cases, incorrect battery parameters can cause this condition to occur with a good battery.