Utility-To-Utility Application; Ejp Function; Control Of Changeover Devices; Control Of Motorised Circuit Breakers - LOVATO ELECTRIC ATL10 Manual De Instrucciones

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UTILITY-TO-UTILITY APPLICATION

– In the utility-to-utility (U-U) application, the load is usually connected to the main utility and the transfer to the secondary utility occurs if/when the main line
anomaly or of transfer signal is given from the outside.

EJP FUNCTION

– For applications requiring the EJP function, it is possible to use two programmable inputs set to functions S.GE (start generator) and E.TR (External transfer)
– Parameter P2.20 can also be used to define a generator start delay.

CONTROL OF CHANGEOVER DEVICES

– For the line changeover, ATL10 can control different types of devices such as motorised circuit breakers, motorised changeovers or contactors
– Depending on the type of changeover devices used with the ATL10, appropriate wiring diagrams shall be used with related programming of programmable
inputs / outputs
– Programmable outputs are set by default for the application with motorised circuit breakers. See the attached wiring diagrams at the end of this manual
– The device status feedback inputs shall be normally wired, so as to ensure reliable system operation
– Nonetheless, it is however possible to avoid their wiring and set programmable inputs for other functions. In this case the unit behaves as if the device
carried out at once the command sent
– If the device status inputs are not used, then ATL10, after power-on, sends an open command to bring the switching devices in a determinate position
– If instead the device status inputs are used, then ATL10, after power-on, does not send commands to the switching device until the relative line status is not
stable, that is when the presence / absence delay have elapsed
– Internal control relays are neither interlocked electrically nor mechanically.

CONTROL OF MOTORISED CIRCUIT BREAKERS

– For the control of motorised circuit breakers, 4 outputs are needed (open and close commands for line 1 and line 2) and two inputs for circuit breakers
status feedback, plus any additional optional inputs for overload protection alarm signalling (TRIP)
– Open and close commands can be used in continuous or pulse mode, i.e. kept until the circuit breaker has reached the required position + safety time
– The two command modes can be selected through the appropriate parameter P2.07 in the general data menu
– If a breaker close command fails, before generating a timeout alarm the ATL10 executes a open command (spring reload) and then re-attempts to close the
breaker. If the operation fails again then the timeout alarm is generated.
– TRIP inputs are ignored for a 15 second window every time an open command is sent to circuit breakers. This prevents a false alarm from being activated if
the circuit breakers temporarily sending the TRIP signal during the opening through trip coil are used.
CONTROL OF MOTORISED CHANGEOVER SWITCHES
– The application with motorised switches is very similar to the previous one, but provides for the use of three outputs only (line 1, line 2 and all open
positions) and two inputs for circuit breaker position status
– CL.1, CL.2 and OP.A output functions and FB.1 and FB.2 input functions are required
– It is possible to select the command mode, either pulse or continuous also in this case.

CONTROL OF CONTACTORS

– If a pair of contactors is used, two outputs (CL.1 and CL.2) and two feedback inputs are required
– In this case, the command must be programmed in contactor mode (P2.07 = CNT).

VOLTAGE CONTROLS

– All the conditions which can help establish whether a power source is or is not suitable are defined by the user through menu P1 (ratings) and menus P3 and
P4 (line 1 and line 2 voltage limits, respectively)
– The system ratings can be set through menu P1, including rated voltage and frequency, which will be used as reference to set percent thresholds
– A voltage ratio (VT ) can be set whenever a voltage lower than the actual system voltage is applied to the unit voltage inputs. Also in this case, both the
visualization and the setting of thresholds will be implemented in actual magnitudes referred to the system
– The controller can be programmed to perform voltage controls on three-phase with or without neutral, two-phase or single-phase utilities (P1.03)
– In the case of three-phase or two-phase utility, you can choose whether to monitor L-L voltage, L-N voltage, or both (P1.04) . In every case, the rated voltage
set with P1.01 has to be equal to the phase-to-phase voltage.
– The following table lists the controls made on each line. The ones marked with OFF may be excluded
Control Description
Minimum voltage One or more phases too low
Maximum voltage One or more phases too high
Phase loss Threshold below which the unit intervention is quicker than
with a normal decrease.
Asymmetry (unbalance) Phases within the Maximum-Minimum range but too different from each other
Minimum frequency Too low frequency
Maximum frequency Too high frequency
Phase sequence Reverse rotation of phases
– Each anomaly has an independent delay time. The anomaly must last uninterruptedly more than the time specified to invalidate the voltage presence signal
– When all the line parameters are restored within the specified limits, before the line may be used, the line presence delay time must elapse. The duration of
this time is specified by two independent parameters, one defining the delay time when the alternate line is available, and a second one, normally shorter, that
defines the delay in case of the alternate line is not available
– All controls, except minimum voltage, may be excluded independently, by setting the relevant parameters to OFF
– The limits of minimum and maximum voltage are specified by setting two thresholds each, one defining the point beyond which voltage is considered no
longer acceptable (e.g. P3.01, drop-out) and the other, nearer to the rated voltage, defining the point where it is again compatible (e.g. P3.02, pick-up). The
distance between these two thresholds defines hysteresis. For instance, it can be stated that below 80% of the rated value, voltage can no longer be used and
that, to be deemed satisfactory, it must rise again above 85%, thus defining a 5% hysteresis (dead-band). The same principle is applied to maximum voltage
– As concerns frequency thresholds, there is a fixed hysteresis equal to 1% of rated frequency
– For the phase loss, the pick-up threshold is the same as the minimum voltage pick-up threshold.
G
B
OFF
G
G
G
G
G
G