Brochures and Data Sheets

NetSure
™
ACU+ Controller (Advanced Control Unit Plus)
User Instructions, UM1M820BNA (Issue AK, March 3, 2014)
Spec. No: 1M820BNA, 1M820DNA Code: UM1M820BNA
Model No: M820B, M820D Issue AK, March 3, 2014
3
• Battery Block and Battery Midpoint Monitoring
• Enhanced Battery Monitoring with SM-BRC
• Thermal Runaway Detection/Management
Spec. No. 588820300 Battery Rack System
(Lithium Ion Battery Configuration)
When the ACU+ is equipped with the Lithium Ion Battery
Configuration for use with Spec. No. 588820300 NetSure™ Battery
Rack System, the battery management functions are as follows.
• The configuration only provides the battery float charge
voltage (equalize charging is not applicable).
• The only adjustable battery setting (besides the float
voltage level) is the ABCL (Active Battery Charge Current
Limit) Point.
• Active Battery Charge Current Limit (ABCL): This feature
controls the amount of charge current supplied to the
lithium-ion batteries installed in the power plant to
prevent failure of the batteries.
• Battery status and alarms sent by the batteries to the
ACU+ are displayed in the ACU+ interfaces.
• Refer also to the instructions provided by the battery
manufacturer for battery management functions built
into the battery itself.
NOTE THAT THE FOLLOWING DESCRIPTIONS ARE FOR THE
GENERAL BATTERY MANAGEMENT FUNCTIONS AND DO NOT
APPLY TO THE LITHIUM ION BATTERY CONFIGURATION.
Battery Charge Temperature Compensation
The ACU+ Controller can be programmed to automatically
increase or decrease system output voltage to maintain battery
float current as battery temperature decreases or increases,
respectively. Battery life can be extended when an optimum
charge voltage to the battery with respect to temperature is
maintained. Temperature is monitored by a sensor mounted on
the battery. See your power system documentation for
temperature sensor information. You can also set High2, High1,
and Low compensation temperature alarms.
Functional Description (See
Figure 2
):
Battery charge temperature
compensation adds a correction term, related to the temperature
of the batteries, to the nominal value of the system voltage. The
degree of regulation (TempComp Coeff), expressed in
mV/°C/battery string, can be set per battery manufacturer
recommendations.
To protect batteries and voltage-sensitive loads, compensation is
automatically limited to a maximum of two volts (48V systems) or
one volt (24 volt systems) above or below the nominal output level
(float setting).
Temperature compensation will also clamp if the voltage reaches
either the TEMP COMP MAX V setting or the TEMP COMP MIN V
setting. This feature can also be disabled.
Temperature compensation is automatically disabled if
communication between the Controller and all rectifiers is lost, a
DC over or under voltage alarm activates, a low voltage
disconnection occurs, manual mode is entered, or the system
enters the boost or test modes.
Battery Equalize Charge and Battery Charge Current Limit
The ACU+ Controller can increase system output voltage for
equalizing the charge on all battery cells of a conventional flooded
cell battery, or for recharging the battery following a commercial
power failure.
The charging function can be initiated cyclically (scheduled),
automatically, or manually.
Refer to the battery manufacturer's instructions for equalize
charging instructions.
FUNCTIONAL DESCRIPTION (SEE FIGURE 3):
•
Start of Charging:
When the battery charge current
exceeds a preset value for 3 minutes or if the calculated
battery capacity has decreased to a preset value (after a
commercial AC failure, for example), the charging
function of the ACU+ is activated. A charging signal is
sent from the ACU+ to the rectifiers to increase the
voltage up to the battery charging level V
equalize.
•
Battery Current Limitation:
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+ limits 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.
•
End of Charging:
When the charging current drops below
a preset value, a defined prolonged charging time is
started before the charging is stopped and the voltage of
the rectifiers return to the float charging level (V
nom
). For
safety, there is a equalize charging limit time that stops
the charging after a preset time.