ABB ATS022, Installation And Operating Instructions Manual

Page: 16 / 44

Installation and operating instructions, ATS022
1SDH000760R0002, L4106
16
3. Description
The switching sequence will be the following:
An anomaly on the normal line occurs
Delay time TS
Start command to the generator
Emergency line OK
Opening of the protection device on the normal line
Delay time TCE
Closing of the protection device on the emergency line
Meanwhile the back-switching sequence will be:
Normal line OK
Delay time TBS
Opening of the protection device on the emergency line
Delay time TCN
Closing of the protection device on the normal line
Delay time TGOFF
Stop command to the generator
Of course the same anomalies in the previous scenario can occur, and in these cases the same
operations are performed, but the following must be considered.
Generator alarm
If the generator alarm input DI8 is activated, the Alarm LED will be switched ON and an alarm message is
shown in the Alarm log of the device (DO6 activated, logic disabled).
3.3.3 Special scenarios
The new ATS022 has to be developed to be compliant with special applications too, in details:
No Line Priority:
in this scenario, none of the two lines is of outmost importance. That means that after
switching the ATS022 remains on the selected power supply line although the previous line starts to work
properly. The logic of the switching is the same as in other scenarios. The only difference is that in this
scenario, there is not a back-switching sequence. This condition has to be set via the Line Priority menu
page.
Two transformers and bus tie (Managing secondary loads): In this scenario, the ATS022 has to be
able to control a third protection device used by the bus tie. ATS022 acquires the open/closed status of
this device with digital input DI11 and by activating DO11 ATS022 is able to disconnect the secondary
loads.