TM 9-6115-658-13&P 2-3 Table 2-1.  Description of Switch Box Controls and Indicators. ITEM NUMBER DESCRIPTION FUNCTION 1 2 3 4 5 6 7 8 SYNCHRONIZING LIGHT ON light for GEN SET 1 (front generator set) ON LINE light for GEN SET 1   (front generator set) ON/OFF switch for GEN SET 1   (front generator set) TRANSFER SWITCH ON/OFF switch for GEN SET 2 (rear generator set) ON LINE light for GEN SET 2   (rear generator set) ON light for GEN SET 2 (rear generator set) Used to synchronize generator sets for transferring load.   All three lights are dark when only one generator set is operating.  The lights simultaneously go from bright to dark and back to bright in repeated cycles after TRANSFER switch (5) is engaged while one generator set is on line and the other is ready to go on line.  All three lights are again dark after load has been transferred. Lights when front generator set is supplying power to switch box. Lights when front generator set is supplying power to the load. Toggle switch, used to place front generator set on line when generator set is ready or take it off line before shutting it down. Toggle switch, used to transfer load when one generator set is on line and SYNCHRONIZING lights (1) indicate that other generator set is ready to go on line. Toggle switch, used to place rear generator set on line when generator set is ready or take it off line before shutting it down. Lights when rear generator set is supplying power to the load. Lights when rear generator set is supplying power to switch box.