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

IB140064EN For more information visit: www.eaton.comInstructional BookletEffective: April 2018 Page 21Operation and Maintenance Manual, Automatic Transfer Switch, Bypass Isolation,Contactor Type, Open/Closed Transition, ATC-900 Controller, 3000A Frame5.3 Switching Mechanism (Manual Operation)A stored-energy type switching mechanism provides the mechani-cal motion required to open and close the main contacts.The transfer switch can be manually operated under load. Beforethe main contacts can be closed, the stored energy mechanismmust be charged by pumping the handle (Figure 25). Each side(S1 and S2) must be charged. S1 is on the left and the handlecharges downward. S2 in on the right with the handle chargingupwards. When power is available, the internal motors will chargethe device. The unit is fully charged when the flags show yellowas shown in Figures 27 and 28. When removing or adding thecover, it is a lot easier to do so if both sides are charged.Figure 25. Pumping Handle Charges Stored Energy Mechanism.The single contator can be used as an open transition or ifordered, a closed transition product. The contactor has rigidmechanical interlocks inside the contactor for open transition toassure that both sources do not close at the same time. There arealso electrical interlocks on all switches. The closed transitiondoes not have mechanical interlocks because the sources aremade to overlap for a maximum of 100 msec as per the specifica-tion for Closed Transition. Since there are two contactors, thereare mechanical and electrical interlocks that are present betweenthe two. These are always provided no-matter if the transferswitch is open or closed type. When a source is closed, the othersource (paddle) should never be closed. A trip open must be initi-ated before any close is initiated. Figures 27 & 28 show the indi-cator window whether the switch is open or closed.Depressing the paddle shown in Figure 26 closes either the source1 or source 2 main contacts. The Green push-button opens bothsets of the main contacts. The optional Kirk-Key locks the mecha-nism and main contacts in the open position.Figure 26. Paddle Closes on Source. Green Push-button OpensBoth Sources. Shown with optional Kirk-Key.Figure 27. Flags Showing Open with Mechanism Fully Charged &Open.Figure 28. Flags Showing Closed with Mechanism Fully Charged &Closed.WARNINGTHE CLOSED TRANSITION PRODUCT CONTAINS A SPECIAL CON-TACT ARRANGEMENT (OVERLAPPING CONTACTS). MISUSE CANRESULT IN DEATH, SEVERE PERSONAL INJURY, AND/OR PROPERTYDAMAGE. NEVER PRESS BOTH CLOSED FOR SOURCE 1 ANDSOURCE 2 AT THE SAME TIME.S1S2