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
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Figure 6. Charge Voltage
Equalize Charge:
The battery will be recharged at equalize voltage.
This is the voltage set in the initial phase of battery recharge. See
Figure 6.
As the voltage limit is reached, the charge current is gradually
reduced – effect known as current tail. When the current tail falls
below a set of threshold levels, additional equalize charge time is
added.
The equalize charge current tail threshold is settable from 0.01 to
0.05. Default setting is 0.02 (2A per 100Ah). The additional
equalize charge time is settable from 0 hours to 7 hours (settable
in minutes from 0 to 720), default setting is 4 hours. The duration
of the equalize charge is determined as the time from the start of
the recharge to the end of the additional time. (Maximum charge
time, determined from the time charge starts, is settable in the
range of 5-24h.)
The end of recharge is determined by a three (3) step approach:
Step1 - calculated battery capacity exceeds 90%. Calculation is
performed by measurement of battery current and time, in
Ah.
Step 2 - charge current tail threshold is reached.
Step 3 - additional charge time is added.
Float Charge:
Default float voltage is 54.0V at 20°C with a
temperature compensation of -72mV per °C.
If battery temperature exceeds 38°C, the charge voltage is reduced
to 51V to reduce gassing and prevent thermal runaway. The same
is applicable as well for equalizing charge.
Equalizing Charge:
As the cyclic use does not ensure complete
battery recharge after every cycle, an equalizing charge cycle is
added. The equalizing cycle will occur up to four times a month,
settable for every 7 to 60 days intervals. Start date and time is
settable. Equalizing charge time is 20 hours independent of
discharge time setting. Equalizing charge is performed at equalize
voltage until end of additional equalize time and thereafter at float
voltage for the remaining time. Also see Figure 6.
Equalize charge independently settable 0-720 min (already set in
equalize charge).
Early Termination of the Discharge Periods
During discharge, over temperature and under voltage conditions
will interrupt the discharge and change the operation to charge –
Diesel Generator ON.
Over Temperature:
The diesel generator will start and run for a
period before it is stopped again. The run time is User selectable in
the range 30 to 120 minutes, default setting is 60 minutes.
Temperature is referenced to cabinet/shelter ambient
temperature sensor connected to the Controller, not battery
temperature. Over temperature start can be disabled completely
from User settings menu.
Under Voltage:
The under voltage start is triggered by under
voltage alarm 2 voltage settings.
The diesel generator will start and run until the normal recharge
cycle is due to finish depending on selected mode of operation.
Example for Fixed Daily Time:
If the normal recharge cycle is from
7am until 7pm and under voltage has started the diesel generator
at 5:30am, the effective recharge will be from 5:30am until 7pm.
Example for Capacity Discharge:
If this mode is selected, the
recharge will terminate.
Operation with Grid Power
Grid power is always prioritized when available. If grid power
becomes available during battery discharge, the discharge cycle is
terminated and recharge cycle is initiated. If grid power becomes
available during diesel generator operation, the diesel generator is
switched OFF and operations continue on grid power.
Battery Recharge with Grid Power:
Battery recharge with grid
power can start from the beginning (case of grid power becoming
available during battery discharge) or can continue over from
diesel generator recharge depending on the timing. In both cases,
the recharge process will follow the recharge profile shown in
Figure 6. If battery becomes fully recharged and grid power is still
present, the operations will continue to be powered from grid and
no battery discharge will be initiated for the duration of grid
availability. In this case battery voltage will revert back to Float
voltage.
Battery Discharge after Grid Failure:
At the point of grid power
failure, the battery capacity is unknown as these events occur in
random manner. For the purpose of maximizing the use of grid
power and in anticipation of grid power becoming available again,