Eaton ATC-900 Operation And Maintenance Manual

Also see for ATC-900: Instruction booklet Manual Operation and maintenance manual Instruction booklet Operation and maintenance manual

Contents

For more information visit: www.eaton.com IB140064ENInstructional BookletPage 6 Effective: April 2018 Operation and Maintenance Manual, Automatic Transfer Switch, Bypass Isolation,Contactor Type, Open/Closed Transition, ATC-900 Controller, 3000A Frame2.5 Draw-out Switching DevicesAll switching devices are 100% rated (including the neutral),Underwriters Laboratories (UL) 1008 listed, and are built andtested in an ISO 9002 certified facility to applicable NEMA, ANSI,IEEE, and UL standards.There is no difference in the bottom contactor vs the top contac-tor. The bottom contactor is referred as the ATS (or #1) and thetop contactor is the Bypass (or #2). Figure 4 shows the two con-tactors in the switch. Either contactor can do all of the transfersfor the loads during the life of the switch. Both contactors aremounted with mechanical and electrical safety interlocks, in a"slide" mechanism (Figure 5), allowing the switching device to be“drawn-out”and isolated for testing or further removed for service,maintenance, and/or replacement.Figure 4. Contactor Devices Installed in the Transfer Switch, Bothare Identical.2.5.2 Draw-out Switching DevicesThe ATS draw-out switching device is a design having three posi-tions with the compartment door closed (RACKED IN, ISOLATED,RAKED OUT). Figure 5 shows the contactor fully disconnectedfrom the transfer switch. It is ready for removal. The ATS draw-out switching device is equipped with both primary and secondarydisconnects to provide for the draw-out functioning. The primarycontacts (Figure 6) are for the high current S1, S2, and load con-tacts. The secondary contacts are the control and feedback con-tacts. The secondary connectors are on the top of the contactorand are somewhat floating for easy racking-in. The operatingmechanism is electrically operated and also has a mechanical man-ual (paddle) operation if required in an emergency. The user canchoose between three modes of operation, Automatic, Non-Auto-matic, and Manual. When removed, either switching device can beinspected, tested, and minor maintenance performed. The insideof the compartment can also be inspected with the ATS switchingdevice withdrawn. Although a shutter is standard, caution mustbe taken as there is voltage on the run-backs (copper) in the backof the cell once the contactor is removed.Figure 5. Draw-out Switching Device Fully Extended for Removal.BYPASSATSWARNINGDO NOT ATTEMPT TO REMOVE EITHER CONTACTOR WITHOUT ALIFTING DEVICE AND BEFORE THE SWITCH IS MOUNTED TO THEFLOOR.WARNINGEXERCISE CAUTION WHEN PERFORMING MAINTENANCE OR SER-VICING EQUIPMENT WHILE IT IS ENERGIZED. FAILURE TO FOLLOWTHIS WARNING COULD LEAD TO DEATH OR SEVERE INJURY. WHILEENERGIZED, AN ARC FLASH AND SHOCK HAZARD EXISTS. CON-SULT NFPA 70E AND OSHA GUIDELINES FOR OPERATOR SAFETYPRIOR TO SERVICING OR OPERATING EQUIPMENT.