Samlex America SCC-30AB - Manuel (Page 31)

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4
PRINCIPLE OF OPERATION & FEATuREs
Voltage Regulation Set Point “Ve” and maintain this voltage level for continuous or cumulative
period of 1/2/3 Hours depending upon the programmed type of battery (Please see Table 6.1
under heading “Standard Battery Charging Programs” on page 43). If “Ve” cannot be maintained
continuously for 1/2/3 Hrs due to inadequate charging current as a result of low / loss of sun light
/ charging current being diverted to load(s), the Equalization Mode will be carried forward till the
programmed hours are completed or in other words, it will get locked in Equalization Stage (the
periods during which the battery voltage falls below “Ve” are not counted towards 1/2/3 hour(s)
time period). The following should be ensured to prevent locking in Equalization Mode:
• There should be no load on the batteries
• The panels should have adequate charging current capacity as compared to the Ah capacity
of the batteries: Short Circuit Current Isc of the panels should be at least 5% to 10% of Ah
capacity of the battery bank
• There should be adequate sunlight – full bright sun for the entire day (no shade or cloud)
Stage 3: Float Stage. The controller enters this stage from the previous Equalization
Stage at point “D1” after the battery voltage is held at the programmed Equalization
Voltage Regulation Set Point “Ve” for continuous or cumulative period of 1/2/3 Hour.
During this stage (Curve portion “D1” to “E1”), the Switch operates under PWM
control by feeding pulsing Short Circuit Current “Isc” with very low Duty Cycle of 0%
to < 10% to keep the battery voltage constant at the Float Voltage Regulation Set
Point “Vf”. During this stage, the battery is 100% charged and a very low “Trickle
Charge” of around 0.1% of the Ah Capacity is required to be fed to the battery to
compensate for self-discharge. The battery can be left at this stage for prolonged
period of time.
During this stage, the LCD Screen 4 (Fig 5.3) displays “State: Float”. Screen 5 (Fig 5.3)
displays the programmed Float Voltage Regulation Set Point (Displayed on the screen
under “Float”).
The Status LED on the Front Panel will be steady Green.
NOTE: During Float Stage, if the load current is more than the current from the solar panel,
the battery voltage will drop. If the battery voltage drops around 1V below the Float Voltage
Regulation Set Point “Vf” continuously for around 1 hour, the controller reverts to Bulk Stage and
the LCD Screen 4 (Fig 5.3) changes to “State: Bulk”.
Manual Equalization
Manual equalization can be selected with the help of DIP Switch 5 located at the back
of the unit (Fig 5.2).
When manual equalization is selected, equalization can be started and stopped
manually with the help of Equalization Button on the front panel of the unit (Fig 5.1).
Please see Table 5.2 under heading “Push Buttons” on page 35 for manual ON / OFF
procedure.
• Switch ON: Press and hold Equalization Button for 5 sec
• Switch OFF: Press and hold Equalization Button for 2 sec
Whenever manual equalization is started, the controller starts from Stage -1 Bulk