Installation and operating instructions, ATS021
1SDH000759R0002, L4106
16
Lim = Voltage threshold
If difference between the rated voltage and measured voltage is greater than threshold value set by
parameter Lim, the line is considered to have an anomaly. The same threshold value applies to difference
between the highest and the lowest phase voltage. Available selections for voltage threshold are:
In MANUAL Mode: ± 5, ± 10, ± 20, ± 30 %
In AUTOMATIC Mode: ± 5, ± 10, ± 20, ± 30 %
By setting the voltage threshold, the unbalance is also set to the same level. (NOTE: Max. +20% for
the main voltage 480 Vac and min. -20% for the main voltage 277 Vac). The operating mode and the
voltage threshold are selected simultaneously by setting the Lim rotary switch to the desired position.
For example, when the Lim rotary switch is set to “20 MAN.”, the device is in the Manual Mode and the
voltage threshold is ±20 %.
4.4 TEST sequence
When pushing the TEST key, the automatic transfer switch (ATS021) enters the test sequence in which it
is possible to simulate switching and back-switching sequences step-by-step, by pressing the TEST key.
ATS021 must be in MANUAL mode before entering the test sequence. Flashing all LEDs twice and then
blinking the Auto LED indicates TEST mode start. Exiting from test sequence is done by RESET key.
Steps in the TEST sequence are:
1.
Press TEST; generator starts (skipped if the generator is not in use)
2.
Press TEST; Open CB1
3.
Press TEST; Close CB2
4.
Press TEST; Open CB2
5.
Press TEST; Close CB1
6.
Press TEST; stop generator (skipped if the generator is not in use)
Pressing TEST after that; sequence restarts. Alarms are activated in the same
way as in automatic sequences, if circuit breaker control fails. The user can
stop the TEST sequence by pressing the RESET key. After stopping the TEST
sequence the device returns to the default page and the settings are exactly the
same as they were before starting the TEST sequence.
Figure 4.6
TEST sequence to simulate the functions
4. Operating
Before starting the TEST sequence, please, make sure that CB1 is in closed position
and the both lines have the voltage on.
