IB140012EN
For more information visit: www.eaton.com
Instructional Booklet
Effective: March 2021
Page
43
Operation and Maintenance Manual,
Automatic Transfer Switch Controller, ATC-900
Appendix B: I/O Descriptions
TYPE
I/O
I/O DEFINITIONS
SUMMARY
6C
I
Remote Engine Test
Provides an input to initiate a test to simulate a loss of the Source 1 as standard. All programmed time delays (TDNE, TDEN, etc.) will be per-
formed as part of the test. Engine run ime of the test is equal to the plant exerciser programmed set point. All tests are fail-safe protected.
The test is initiated via remote momentary contact closure.
8E
I
Bypass Timers
The Time Delay Bypass Pushbutton contact, when closed, will reduce any or all of the programmed time delay to zero. Must be executed when
the appropriate timer is displayed on the controller. The bypass time delay feature is initiated via remote momentary contact closure. (The
front of the controller has a Bypass Timer also).
8F
I
Bypass Timers w external
push button
Provides a means to bypass the time delays with via a device panel mounted push-button switch.
10A
I
Preferred Source Selector
Provides a means to designate either Source 1 or Source 2 as the “Preferred” Source using a remote contact or device panel mounted contact
closure. The “Preferred” Source is the source that the transfer switch will connect the load to if it is available. The Preferred Source setpoint
must be set to "External" to use this feature.
10C
I
Preferred Source Selector w/
selector switch
Provides a means to designate either Source 1 or Source 2 as the “Preferred” Source via device panel mounted selector switch control. The
“Preferred” Source is the source that the transfer switch will connect the load to if it is available. The Preferred Source setpoint must be set
to "External" to use this feature.
23N
I
Engine Test Mode Select
Input to enable load or no load test
26D
I
Go to Emergency (S2)
Provides a means to send the switch to the Non-preferred (Emergency) sourceproviding the voltage and frequency are within the limits of the
setpoints. This signal will initiate an engine start.
26E
I
Go to Emergency (S2) Input
w/selector Switch
Provides a device panel mounted selector switch labeled, "Auto/Go to Source 2", to initiate a transfer to the Source 2 power source. This
includes starting the generator, performing the programmed time delays and the transfer operation. Re-transfer will occur when the external
contact is opened. This is a fail-safe function.
29E
I
ATS in Bypass
A signal to the controller to specify that the switch is in the bypass position
29G
I
Selector Switch for Auto &
Non-Auto
Provides a device panel mounted selector switch to specify if the switch is in the automaitc or normal mode or if the switch is in Non-auto-
matic electrical mode.
29K
I
Enable Manual Retrtansfer
Provides an input to remotely initiate a manual retransfer from the Non-preferred source to the Preferred source.
29J
I
Enable Manual Pushbutton
Transfer E to N or N to E
Provides an input to remotely initiate a manual retransfer from the Non-preferred source to the Preferred source or vice-versa.
29L
I
Manual Retransfer On/Off
Provides an input to remotely enable or disable the manual retransfer feature.
29M
I
Manual Retransfer On/Off
Input w/selector switch
Provides an device panel mounted selector switch to enable or disable the manual retransfer feature. Selection of this option automatically
adds option 29J.
36
I
Load Shed - Emergency
Inhibit
Enables load shed (S2 Inhibit), See 36A
36A
I
Load Shed - Emergency
Inhibit w Keyed Switch
Provides a device panel mounted selector switch to initiate a load circuit disconnection from the Source 2 power source. If the load circuit is
connected to Emergency and the selector switch is switches to the "S2 Inhibit/Enabled" position, then a re-transfer to Source 1 is completed
if Source 1 is available. If the Preferred Source is not available, then the transfer switch will transfer to neutral. If the load circuit is connected
to Source 1 and the switch is in the "Emergency Inhibit" position, then a transfer Source 2 is prohibited.
37
I
Go to "Isolated" Position
Provides an input to transfer a 3 position transfer switch (source 1/off/source 2) to the off position using a remote contact closure. When the
signal is removed, the transfer switch will transfer back to the available, prefrred source.
81J
I
Lockout
Provides an input to temporarily disable automatic control. This feature is used to indicate a tripped breaker in a breaker based transfer
switch. It is treated as an alarm and the alarm must be rest to continue automatic operation.
81K
I
Monitor Mode (N.O. or N.C.) Provides an input to disable automatic control in the ATC-900 controller. This function is used for when manual operation is required. The
controller continues to accurately monitor source status and set points can be changed, however no action will be inititated by the controller.
There are two settings, N.O. and N.C.
81P
I
Contactor Bypass Safety
Interlock Alarm
Whenever the contactor bypass will not operate automatically because of items as: a Door Open, a Contactor(s) not locked in, not in auto-
matic, in Monitor Mode, etc. Also can be monitored by Mod-bus and Ethernet.
81R
O
Waiting for Sync
Provides an output that closes when closed or in-phase
81S
I
Closed Transition Inhibit
An input, when closed, will inhibit closed transition. The transition will now be an open type (depending on what the open set point is set to)
90B
I
Secondary Input
The ATC-900 Primary/Secondary controller functionality provides the user with the ability to use two independent transfer switches in three
source systems consisting of a utility and two generator sources. In a three-source system, the Primary ATS controls the engine starting and
stopping of the Secondary ATS. The Secondary input receives the engine start signal from the Primary controller.
14C
O
S1 Available
The ATC-900 will measure voltage and frequency and if they are measured in the envelope of the settings an Output will show that S1 is
Available
14D
O
S2 Available
The ATC-900 will measure voltage and frequency and if they are measured in the envelope of the settings an Output will show that S2 is
Available
15R
O
Normal (S1) Source Position
1 Form C
Provides 1 form-c relay contact that indicates the position of the source 1 power switching device.
15S
O
Emergency (S2) Source Posi-
tion 1 Form C
Provides 1 form-c relay contact that indicates the position of the source 2 power switching device.
35A
O
Pre-Transfer Contacts
Provides a signal prior to the transferring of the load. Will not transfer until the programmable delay set point in the controller is reached. If
both sources are not available, this option will ignore the time delay set in the controller.
35D
O
Post Transfer Contacts
Provides a signal after the transferring of the load to the delay set point of the controller when reached.
