Battery Current Sensor - SMA Sunny Island 2012 Technical Description

SMA Solar Technology AG

7.6.2 Battery Current Sensor

In addition to the internal measurement, the Sunny Island provides the possibility to measure the
battery current via a shunt. You need this function if you intend to operate additional DC generators
and DC loads in your island grid system.
NOTICE!
Damage to the battery due to the connection of additional DC generators or DC
loads to the island grid system.
In this operating situation, the Sunny Island's internal current measurement works
imprecisely; the charge state of the battery is not determined exactly.
• Install an external battery current sensor (shunt).
Battery Current Sensor
Install a battery current sensor if there are charge or discharge DC currents of over
200 A.
Connect the battery current sensor to the master.
Use cables of intrinsically safe circuits.
Always use cables of intrinsically safe circuits for the connection of battery current
sensors. "Intrinsically safe" means here that the cable is double-insulated and that the wire
melts but the insulation remains intact in the event of a short circuit. In addition, the cable
is not combustible. In order to avoid measuring errors, make sure to use twisted cables
(see DIN VDE 0100-430).
When connecting the battery current sensor proceed as follows:
1. Pierce the rubber plugs with a pointed tool.
2. Fit the cables with wire sleeves.
3. Introduce both cables from the outside through
the opening.
Technical Description
Sunny Island Electrical Connection
SI2012_2224-TEN082311 61