Operating Mode Selection; Off-Reset-Man-Aut-Test Mode; Main Line Failure Simulation; Utility-To-Generator Application - LOVATO ELECTRIC ATL20 Manual Operativo

STATUS LEDS
– Some LEDs are present on the front panel; they show the status of the unit and/or circuit breakers it controls.
– The following table details the meaning of the different LEDs. Some of them have two colours and have a different meaning depending on the colour.
LED ON
Voltage and frequency within set limits
LINE OK
ON ‚
Closed circuit breaker (green)
WITHDRAWN ƒ
Circuit breaker withdrawn
TRIP ƒ
Trip signal without alarm
ALARM ––
TEST Automatic test enabled (green)
‚
If auxiliary signals (feedback) have been suitably connected and programmed, the LEDs represent the circuit breakers status; otherwise they represent the status of
control outputs.
ƒ
If the respective signals were suitably connected and programmed, the LEDs represent the circuit breakers status; if not, LEDs will remain off.

OPERATING MODE SELECTION

– The four keys OFF-RESET / MAN / AUT / TEST allow to select the required operating mode, which will be shown when the relevant red LED lights up.
– If the LED showing the selected operating mode flashes, it indicates that the unit is communicating through the serial interface and that it might perform
commands given from remote, including even the change of the mode itself.
OFF-RESET MODE
– In this mode, the unit is disabled, and does not perform any actions.
– All viewing, concerning both measurements and status LEDs, remain active.
– If the control of changeover devices is the pulse-type, in OFF-RESET, both controls remain disabled. On the contrary, if it is in continuous control mode, the
action depends upon P2.25 programming.
– To access programming menus, it is always necessary to shift to OFF-RESET mode beforehand.
– By pressing the OFF-RESET key, retentive alarms can be cleared, provided that the conditions generating the alarm have been removed.
MAN MODE
– In MAN mode, it is possible to control circuit breakers manually by pressing the relevant key (C and D keys) for a minimum time of 300ms.
– At each key pressure, the circuit breaker status is switched over. The command is accepted only when 1 second has elapsed from the end of the previous
switching.
– If a manual command is given to close a circuit breaker while the other is still closed, the unit will first open the other circuit breaker and then close the one
commanded, while interposing the programmed interlock time.
– When operating with a generating set, the generator startup and shutdown can be manually commanded on the secondary line by pressing and holding down
the MAN key for 5 seconds.
AUT MODE
– In automatic mode, the unit performs by itself both circuit breaker opening and closing operations, the startup and shutdown of the generating set, if any.
– When the main line exceeds the limits, after the set delay times (line LED off), the unit disconnects the load from the main line and connects it to the
secondary line, controlling both the startup of the generating set, if any, and the switching and interlock times between circuit breakers.
– The unit may be programmed to disconnect the load from the main line before or after the secondary line has been made available.
– When the main line returns within the limits, the unit switches over the load again and controls the generating set cooling cycle, if any.
– Automatic operating cycles vary both as a function of the type of application (utility-to-utility, utility-to-generator or generator-to-generator) and as a function
of the type of switching devices used (motorised circuit breakers, motorised changeover switches or contactors).
TEST MODE
– The TEST mode allows to control the proper operation of the generating set also under standard presence conditions of the main line.
– When shifting to TEST, the generating set on the secondary line is immediately started.
– Both voltage controls are activated and, if an anomaly occurs on the main line during the test, the load is switched over automatically.
– Under standard conditions of main line presence, the load remains on the line and the generating set works with no load (off-load test).
– If you want to shift the load to the generator (on-load test), press key
E (TEST) and key D (line 2 ON-OFF) together for 5 seconds.
– In TEST mode, once the load has been shifted to the generator, either due to a main line failure or to perform an on-load test, it does not automatically return
to the main line, unless you switch to AUT mode.
– Delay and interlock times are the same as in the automatic mode.

MAIN LINE FAILURE SIMULATION

– Starting from the automatic mode, it is possible to simulate a 1-minute voltage failure on the main line.
– The unit will respond in the same manner and timeframe set for standard automatic operation. The proper operation of transfer cycles may thus be
controlled.
– Starting from AUT mode, press the AUT key and the line 2 ON-OFF key together for 10 consecutive seconds.
– The letters F.SI (Failure Simulation) will be shown on the display during the whole cycle operation.
– To stop the test before completion, repeat the starting procedure or switch to
OFF - RESET mode.

UTILITY-TO-GENERATOR APPLICATION

– In the utility-to-generator application
(U-G, default setting) the load is usually connected to the utility (Line 1). Following voltage or frequency anomaly, after the delay set in P2.15, a start signal is
sent to generator (Line 2).
– When generator voltage is within programmed limits, the load is connected to the generator end until the utility line returns within standard values.
– At this time, the load is transferred back and the generator is kept in operation without load for a time set by P2.16 to allow it to cool.
– The ATL controller sends a start/stop command to the generator through a relay output and can receive digital signals from the generator indicating its status
(generator ready, ok to load taking, etc) through programmable inputs.
– An automatic test can be programmed, i.e. the generator can be started at set times to control its operation even if the utility is generally within limits, by
setting run interval, starting time, days of the week when the test shall be carried out, its duration, etc. Refer to the relevant menu to set the automatic test.
OFF
Voltage or frequency out of limits
Open circuit breaker
Circuit breaker inserted OK
No protection trip
No active alarm
Automatic test disabled
FLASHING
Presence delay time or failure in
progress
Operating circuit breaker (green)
Timeout (red)
Circuit breaker withdrawn alarm
Protection alarm tripped
One or more active alarms
Automatic test in progress (green)
RTC not set (red)
3
G
B