Residual-current monitoring unit (RCMU)

The product is equipped with an all-pole sensitive residual-current monitoring unit in accordance with IEC/EN 62109-2 and VDE 0126-1-1. The all-pole sensitive residual-current monitoring unit monitors residual AC and DC currents. It disconnects the product redundantly from the utility grid in the event of residual current jumps of > 30 mA. Even if the residual-current monitoring unit malfunctions, all poles of the product are immediately disconnected from the utility grid. The product therefore does not require an external residual-current device for safe operation. If local regulations require the use of a residual-current device, the following must be observed:

• The inverter is compatible with type B residual-current devices. For SHP 100-JP-21 the rated residual current must be 1000 mA and for SHP 143-JP-21 the rated residual current must be 1500 mA or higher (for information on selecting a residual-current device, see Technical Information "Criteria for Selecting a Residual-Current Device" under www.SMA-Solar.com). Each inverter in the system must be connected to the utility grid via a separate residual-current device.

• When using residual-current device with a lower rated residual current, there is a risk of false tripping of the residual-current device, depending on the system design.