turn power off at mains open the panel some early lock out units where stand alone units,i dont use your type, of panel so cant say if its inbuilt,if you see a printed circuit board with 4 wires goin g to it,two will be live and neutral,two will be connected to a zone ,and zone wires will be connected to the pc,the board will be a small unit about 2 inches square its worth a look
gts, February 2013