GE Industrial Solutions CPS6000 - Manual (Page 194)

CPS6000 –48V Indoor/Outdoor Power Shelf
Issue 21 January 2008
194
Recharge Amp Limit: This section contains the settings for battery recharge current limit.
Limit: Enable or disable battery discharge current limiting.
Limit To: Current limit setting, from 5A to 100A. The factory default setting is 50A.
During this test, the controller lowers the rectifier voltage to 44V. (This value was chosen to
be higher than 1.2V plus the highest possible LVD contactor disconnect threshold so as not to
accidentally open the LVD contactor.) Lowering the rectifier output voltage to 44V creates a
battery on discharge condition. If the batteries are present and healthy, the plant voltage will
remain above 48V and the batteries will support the load. If the batteries are not present or are
not able to support the load, the plant voltage will immediately drop to approximately 44V
without any consequence to the load. The Battery on Discharge alarm is masked during this
test.
The test is terminated by the occurrence of any of the following conditions:
• Initiating another Plant Battery Test. That is, once the test has been initiated, the test
may be stopped by initiating another test either through the controller or by shorting
pins 19 and 20 of the host interface connector.
• An alarm condition occurring. Any alarm condition that occurs during this test will
result in the test being aborted regardless of whether the contact-closure exists between
pins 19 and 20 of the host interface connector.
• The test has continued for over 100 minutes.
• The plant voltage has dropped below 44V. In this case, the system will abort the test
and resume rectifier operation.
After the test has stopped, the plant will revert to the float mode. It may go to boost mode if
the auto-boost feature has been enabled.
Boost Mode
Boost charging is a feature of the QS840A controller, which allows the user to temporarily
raise the plant voltage to a higher, predetermined level in expediting the time needed to
charge batteries. The system may manually be placed in the boost-mode through the front
panel.
Note that the measured boost voltage may not exactly match the value chosen by the user if
the thermal compensation feature is enabled. This is because the QS840A performs thermal
compensated boost charging and will adjust the boost value based on the battery temperature
per the slope chosen by the user.
The plant will exit the boost mode and enter the float mode if any of the following occurs:
• The current flowing into the battery string(s) is less than 5A
• The duration of boost mode charging has reached 8 hours