UM582127000 User Instructions
Issue AC, January 2, 2013 Spec. No. 582127000 (Model 721NPBB)
Page 4 Chapter 2. Operating Procedures
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CHAPTER 2. OPERATING PROCEDURES CONTROLLER, RECTIFIERS, AND OPTIONAL CONVERTERS
For operation instructions on these units, refer to the following documents.
ACU+ Controller Instructions (UM1M820BNA)
Rectifier Instructions (UM1R483500E or UM1R482000E3)
Converter Instructions (UM1C48241500)
ESTOP FUNCTION
If an ESTOP switch is wired to the ACU+ IB2 Interface Board, customer-furnished system
ground applied to terminal DI8+ activates the ESTOP function. The ESTOP function
shuts down and locks out the rectifiers, opens the LVD’s, and shuts down the converters.
When the ESTOP signal is removed, LVD’s close (if battery present) and converters
restart. To restart the rectifiers; turn AC power to the rectifiers OFF, wait 30 seconds or
more (until the LEDs on the rectifier extinguish), then turn AC power to the rectifiers ON.
Rectifiers can also be restarted from the ACU+ LCD or WEB Interface menu (via the
Rectifier Reset command, found in the Manual menu in the LCD menus or under the
Rectifier Control Tab in the WEB Interface).
ACU+ BATTERY CHARGE CURRENT LIMIT FEATURE
Functionality: After a commercial AC failure or when some battery cells are permanently
damaged, the current to the batteries can be quite extensive. To avoid overheating or
further damages to the battery, the ACU+ can be programmed to limit the battery current
to a preset level by limiting the charging voltage of the rectifiers. Should the battery
current still exceed a higher preset value, an alarm is issued.
In this system, the ACU+ Battery Charge Current Limit feature is set to be disabled.
Refer to the ACU+ Controller Instructions (UM1M820BNA) to enable and program this
feature, if desired. If enabled, battery charge current is limited to the value set in the
ACU+ Controller, as long as battery voltage is above 47VDC.
LOCAL CONTROLS AND INDICATORS
Refer to the Controller, Rectifier, and Converter Instructions for descriptions of the local
controls and indicators located on these units.
Refer to this section for descriptions of the local controls and indicators located on the
circuit cards installed inside the distribution cabinet.
Circuit Card Locations
Refer to Figure 2-1.