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IM05805022K
Instruction Booklet
Page
18
Effective: January 2012
ATC-300+ Automatic
Transfer Switch Controller
Generator Start Relay
This latching relay is the generator start relay for system configu-
rations that employ a generator as the Source 2 power source.
This relay provides a Form A contact of silver alloy with gold
flashing for closure of the generator start circuit.
The Form A contact is implemented with the Common Pin (J-5,
Pin 13) and the Normally Open Pin (J-5, Pin 14). The generator
start relay contacts are rated for 5 A, 1/6 HP @ 250 Vac. The DC
rating is 5 A @ 30 Vdc with a 150 W maximum load.
Alarm Relay
The alarm relay is de-energized to indicate an absence of an alarm
state and energized to indicate the presence of an alarm condi-
tion. Alarm conditions include the following.
1. Improper circuit breaker (or contactor) operation (breaker
[or contactor] fails to open or close within six [6] seconds)
2. Motor operator failure (Breaker Type ATS only)
3. Lockout
4. Failsafe condition
5. Aborted engine test due to Source 2 unavailability
6. Aborted plant exerciser test due to Source 2
unavailability
The alarm relay will remain energized until “Alarm Reset” is
pressed.
The full Form C contact of this relay may be wired to an alarm
annunciator panel to indicate a problem with the ATS. The full
Form C contact of this relay is implemented with the Common Pin
(J-5, Pin 8), the Normally Closed Pin (J-5, Pin 10), and Normally
Open Pin (J-5, Pin 9). The alarm relay contacts are rated for
10 A, 1-3 HP @ 250 Vac. The DC rating is 10A @ 30 Vdc.
Pre-transfer Relay
This Form C relay opens/closes on a timed basis (adjustable from
1 to 120 seconds) prior to the transfer operation between two
available sources to allow the load to be de-energized prior to
transfer in either direction. After TDNE/TDEN times out, this relay
energizes and the Pre-transfer timer (TD PRE-TRAN) starts timing.
After TD PRE-TRAN times out, the transfer proceeds. The pre-
transfer relay de-energizes after the transfer is complete.
The full Form C contact of this relay is implemented with the
Common Pin (J-5, Pin 5), the Normally Closed Pin (J-5, Pin 7),
and the Normally Open Pin (J-5, Pin 6). The pre-transfer relay
contacts are rated for 10 A, 1-3 HP @ 250 Vac. The DC rating is
10 A @ 30 Vdc.
5.5.1.2 Transfer Operations Connections
K1, K2, K3, and K4 are factory wired to operate the transfer
switch. The relay contacts for each are rated for 10 A, 1/3 HP @
250 Vac. The DC rating is 10 A @ 30 Vdc. K1 - K4 are Form C
relays but only the Form A contacts are used to operate the trans-
fer switch.
Note:
The ATC-300+ Controller MUST BE properly grounded at J-5, Pin
12 for proper operation.
Output Relay K1
This Form A relay is used for control of the transfer switch motor
to close the Source 1 breaker/switch for breaker/switch style
transfer switches. The K1 relay momentarily energizes until the
ATC-300+ senses that the Source 1 breaker/switch is closed,
then K1 de-energizes. The K1 outputs are common pin (J-5,
pin 1) and Normally Open pin (J-5, pin 2).
Output Relay K2
This Form A relay is used for control of the transfer motor to close
the Source 2 breaker/switch for breaker/switch style transfer
switches. The K2 relay momentarily energizes until the ATC-
300+ senses that the Source 2 breaker/switch is closed, then K2
de-energizes. The K2 outputs are common pin (J-5, pin 3) and
Normally Open pin (J-5, pin 4).
5.6 Operating Voltage and Measurements
The ATC-300+ Controller operates with control power from
65 to 145 Vac. The ATC-300+ operates on single and three
phase systems with selectable frequency settings of 50 or 60 Hz
depending on the system ordered.
The ATC-300+ can perform the time delay engine start function
without control power. This is accomplished by the use of a
supercap and a latching control relay. The supercap stays
charged for several minutes to power the logic circuitry that pro-
vides the start pulse to the latching control relay. The latching
control relay, which controls the generator, only changes state
when it receives start or stop pulses. The coil voltage for the
latching relay comes from another capacitor that also stays
charged for several minutes.
The ATC-300+ Controller operates directly from the line sensing
inputs of the Source 1 and Source 2 power sources. The nominal
operating system inputs are from 120 to 600 Vac. The standard
system assumes that neutral is available and that the transfer
mechanism can therefore be powered from an available 120 Vac
source.
All voltage monitoring and measurements are true RMS measure-
ments.
