Eaton Cutler-Hammer ATC-300 - Dual Utility Transfer Switch Flowchart

IB01602009E For more information visit: www.eatonelectrical.com
Instruction Booklet
Effective: April 2006 Page 27
ATC-300 Automatic
Transfer Switch Controller
Dual Utility Transfer Switch
Source 1 is available
Close Source 1
(Energize K1)
Source 1 is powering the load
Source 1 becomes unavailable
(or Go To Emergency)
Is Source 2
Available?
TDNE timer times out
Open Source 1
(Energize K2)
Close Source 2
(Energize K4)
Source 2 is powering the load
Is Source 1
Available?
TDEN timer times out
Ye s
No
No
Ye s
Open Source 2
(Energize K1)
Close Source 1
(Energize K3)
Source 1 is powering the load
Sends pretransfer signal
TPRE timer times out
(If Source 1 is Available)
Sends pretransfer signal
TPRE timer times out
Note: Programs TDES, TDEC, and TDEF Setpoints to 0 seconds.