PREN 50330-1 : DRAFT 99

1 Scope
2 Purpose
3 Normative references
4 Requirements
  4.1 General Requirements
  4.2 Specified Requirements
5 Type test
  5.1 The test for single fault safety, including the
      detection of faults entailing a blockage in accordance
      with 4.2, is effected by fault simulation
  5.2 The test circuit simulates islanding conditions
      under which the MSDs must defect the interruption of
      the mains circuit and disconnect the feed from the
      house-load generator by means of the switching devices
      from the mains in the affected external and neural
      conductors within 5 s (Figure 2):
  5.3 The procedure of the MSD test is as follows:
  5.4 In order to test the overvoltage and undervoltage
      controlling device, the inverter has to be connected
      via a transformer with a varying transformation ratio
      and operated at a rated a.c. voltage and a random
      output
  5.5 In order to test the a.c. voltage characteristics
      during short circuit condition, the inverter has to be
      operated at the rated output and a short circuit has to
      be caused at the output with a resistance of 1 W. The
      voltage drop at this resistance is to be measured on
      an oscilloscope from the time the short circuit has been
      produced up to the moment the stationary state has been
      reached
6 Routine test
7 Rechecks of automatic disconnecting facilities
8 Installation

Describes the general design principles and test procedures to a fail safe protective interface, which has to disconnect automatically the link between the power conditioning subsystem and the utility grid, if there are needs on the utility or the user side.