DESCRIPTION

        The Isotel series devices have been developed by Soluciones Energéticas to cover the control and regulation necessities of medium power stand alone photovoltaic systems. The main technical characteristics are shown below:

        - Series type regulation with microprocessor control and solid state relays.

        - Various versions depending on the number of stages required. Each stage allows the input of up to 30A (at 12 and 24V) or up to 20A (at 48V). The standard version allows up to four input stages but they can be manufactured with up to eleven stages upon request. Under requirement they can be manufactured to reach eleven stages.

        - Regulation system using deep charge and flotation, thereby allowing periodic equalizing charges in automatic and manual modes.

        - Battery voltage control line independent from the power line, avoiding voltage measurement errors caused by the high currents that can flow by the battery line.

        - Load disconnection due to low battery voltage, with automatic reconnection.

        - Temperature compensation of the threshold voltage set points using an incorporated temperature sensor.

        - LCD (4 rows x 16 characters) display showing the following parameters: system voltage, total and partial current generated, load current, generated, consumed and accumulated Ah by stage, sensor temperature, charge balance, date and time, etc.

        - State of charge indication and local alarms of low and high battery voltage using LEDs and display.

        - Alarms (using voltage-free relays) of  low and high battery voltage, PV module generation fault, general system faults and start-up of an auxiliary generator.

        - Two 0 to 5 V auxiliary inputs (irradiation, ambient temperature measurement or similar). Possibility (upon request) of alarms associated to these inputs.

        - Day/night detection for the activation of buoys or beacons.

        - Predefined battery voltage threshold table in the software with the option of password-protected value modification.

        - Waterproof box with transparent front panel.

        - Protection using magnetothermic switches of the PV module, battery and load lines.

        - Protection against overvoltage in the power input and control lines.

        - Self protection against overcurrent and overtemperature.

        - Protection against battery disconnection.

        - Protection against polarity inversion in the power and control lines.

        - Protection against disconnection and short circuit of the temperature sensor.

        - Four languages of the display information: Spanish, English, French and German.

        - Gold plated (flax level), flat polarized connectors between the power stages and control board.

        - Circuit tropicalization and internal cabling identification using colours and numbers.

        - Digital communication line for data transmission, via RS232, in the standard model. This line allows the adquisition of system information via modem and even remote parameter modification.

        - ISPRA report generation through the RS-232 line, with a user defined interval. A serial printer can be conected to the RS-232 port for direct printing of the reports.
 

        INFORMATION SHOWN ON THE DISPLAY

        When the device is switched on, the version and serial numbers will be displayed for a few seconds; another screen will then appear showing the address and the phone number of the manufacturer (Soluciones Energéticas) or distributor (in the OEM version). This screen will be shown for a few seconds and will reappear every four information cycles. If the screen are changed manually, this information is not shown.

        Once these first screens disappear, the charge controller will start its normal operation and information will be displayed on the screen in a cycle of a predefined interval, this cycle will show information about the temperature, currents, instantaneous powers, energy generated, etc. Each of these screens is briefly described below:

        Battery state: shows the battery voltage and state of charge, the charge phase of the controller is also shown (gassing charge, floating, etc).

        Storage: shows the instantaneous value of the total generation current, the Ah accumulated at the time of consultation and the balance (Ah generated - Ah consumed). This last parameter provides a relative indication of the state of charge of the battery.

        Load current: provides information about the instantaneous and maximum load current.

        Generation current: provides information about the instantaneous and maximum generation current.

        Load power: shows the instantaneous and maximum load power.

        Generation power: shows the instantaneous and maximum generation power in each generation stage and the total for all the stages.

        Energy: shows the energy generated and the energy consumed (in Watt hours) since the device started operation or the counters where last reset.

        Alarms: inform about the state of the device alarms. The alarms screen has three rows in which the remote alarms of the device (K1-K6) are shown, followed by the message "SI" ("YES") if the alarm is activated or "NO" ("NO") if the alarm is not activated.

        System: provides information about the device: serial number, software version and the number of output stages installed.

        Temperatures: shows the instantaneous, minimum and maximum temperatures since the device started operation or since the registers where last reset.

        Watch: shows the date and solar time.

        External lines: shows the voltage level as a percentage of 5V of the two external auxiliary lines incorporated into the device.
 

        INDICATOR LIGHTS

        The charge controller has three indicator lights indicators (LEDs) that allow the user to obtain direct, visual information about the state of charge of the batteries.

        - Red LED: low charge level. Lights up when the battery voltage has remained lower than the level predefined as Low Battery Voltage Alarm for more than 10 seconds. The low voltage alarm disappears when the battery voltage increases above the voltage value predefined as End of Low Battery Voltage.

        - Yellow LED: activates when the battery voltage is higher than or equal to the maximum battery voltage value allowed for more than 10 seconds. The High Battery Voltage alarm switches off when the battery voltage drops below the End of High Battery Voltage threshold.

        - Green LED: shows the state of the solid state relays of the generation circuit. No light means closed relay (conducting).

        During charge controller operation in flotation or equalizing phases, this LED will blink, indicating that the charge controller will connect and disconnect the generation stages to maintain the battery within the predefined voltage thresholds.