Control Functions; Active Voltage Control; Battery Current Limit (Bcl); Battery Test - Eaton SM65 Handbook

A p p e n d i x B

Control Functions

Active Voltage Control

Active Voltage Control (AVC) maintains a constant float voltage under varying load current
by monitoring the bus voltage and adjusting the rectifier output voltage to compensate for
any voltage drop.
Enable AVC to prevent undercharging the batteries during high load demand.
Active Voltage Control does NOT function during a Battery Test or if the battery current is
negative.

Battery Current Limit (BCL)

Battery Current Limit automatically limits the battery recharge current to:
Prevent overcharging of the batteries in under-loaded systems
•
Minimize gas release in VRLA batteries
•
Two current limit values can be set (both are a percentage of the C10 rating of the battery):
Battery Current Limit:
Engine Run Limit
(optional):
Engine Run Limit is activated by a signal from an AC standby engine-alternator.

Battery Test

Battery Test is a preventative maintenance tool that monitors the discharge capabilities to
ensure that the condition of the battery has not deteriorated over time.
The SM65 temporarily reduces the output voltage of the rectifiers to just below the bus
voltage for a set duration. The battery then supplies power to the load. A battery test passes
if the battery voltage remains above a predetermined level for the duration of the test.
Battery Tests can be scheduled to occur at regular intervals, and/or can be started/stopped
manually, and/or can be started by an external relay contact or switch.
Battery Test does NOT function during a Fast Charge or Equalize, or during the first 48 hours
after an AC power outage.
If a Digital Input has the function "Start Battery Test" then a Battery Test will be started
when the Digital Input is active.
BCL value for use when utility AC is available.
BCL value for use when AC is supplied by a standby engine-
alternator (EA). This reduces the load on the EA and allows a
smaller EA to be used.
Copyright © 2004-2009 Eaton Corporation. All Rights Reserved.
IPN 997-00012-35E
Control Functions
December 2009
Appendix B
51