AUTOMATIC TRANSFER SWITCH CONTROLLER
Automatic Transfer Switch Controller Tutorial Page
In the standby application, the automatic transfer switch controller assigns the UTILITY POWER as a primary source. The electric generator is the emergency source of power. The electric generator may consist of a diesel generator or an inverter supported by a battery bank.
THE AUTOMATIC TRANSFER SWITCH CONTROLLER TUTORIAL
THE AUTOMATIC TRANSFER SWITCH CONTROLLER RELAY INTERFACE BOARD
The relay board module features all removable connectors needed to interface with the engine, the generator, the mains, the motorized changeover, and miscellaneous input-output lines.
The label on the top of the module indicates all functions. The board is supplied from the engine's battery via automotive blade terminals. The following sections will explain all the details.
THE AUTOMATIC TRANSFER SWITCH CONTROLLER DRIVES MOTORIZED CHANGEOVERS
INTERFACE BOARD DIMENSIONS
This ATS controller board interface features a metallic cover. Electric noise generated by the changeover will not affect the accuracy of the electrical measurements.

This ATS controller extension board includes 7 relays committed to driving the engine auxiliary circuits and the changeover coils.

The board features electronic fuses and glass fuses to protect the coils of the changeover. The installation of this board drastically reduces the component count of your bill of material. Not to mention the time you save assembling this item. The total weight is about 500 grams.
THE AUTOMATIC TRANSFER SWITCH CONTROLLER DRIVES CONTACTORS
CONTROLLER INPUTS
The controller interfaces with all kinds of switches and offers 3 fully configurable inputs. For each input, you can choose one of the 28 options. By default, input 3 is configured to "REMOTE ENGINE TEST INPUT".

In the same way, input 2 is configured as "REMOTE LOCK INPUT", while input 4 is configured as "MAINS SIMULATED INPUT". All inputs are protected against overvoltages, AC voltage p to 50V, and reverse polarity.
CONTROLLER OUTPUTS
The controller DC outputs feature short circuit-proof relays. The outputs are designed for driving automotive relays. The total current delivered by the outputs may not exceed 4A. Over this current, the controller triggers the output short-circuit protection.

The OUTPUT 1 is programmed by default as "ALARM OUTPUT". You can connect a sound alarm. The OUTPUT 2 is programmed by default as "PREGLOW". You may install a pilot relay to start a diesel engine. ATS CONTROLLER INSTALLATION MANUAL lists over 50 available options.
VOLTAGE MEASUREMENTS
The ATS controller directly interfaces with GENERATORS and UTILITY POWER LINES up to 600Vac. The fuses indicated in the picture are mandatory. These fuses (or a circuit breaker as an option) protect the wires in case of a direct short-circuit.
You will find more details about contactors or motorized switches driving in our tutorial:
CURRENT MEASUREMENTS
We always recommend to install CURRENT TRANSFORMERS of a suitable size. You will have a precise measurement of the current that flows in your LOAD, and you can set warnings and shutdowns in case of an OVERLOAD.

The ATS controller interface with current transformers from 50/5A up to 1000/5A
AUTOMATIC TRANSFER SWITCH CONTROLLER DIAGRAM
The AUTOMATIC TRANSFER SWITCH connects the LOAD via the KM or KG. The KM auxiliary contacts are closed when the KM is open. On the other hand, the KG auxiliary contacts are closed when the KG is open. When switching the LOAD to UTILITY POWER, the controller triggers a programmable DEAD-TIME delay. This will avoid sparks, over voltages. and over currents when the LOAD is highly inductive. This is the case with big electric motors, In other words, before energizing a heavy LOAD, the Be242 controller waits for a while. Set the dead time between two and ten seconds.
CLICK ON DIAGRAM, OPEN HD EXPLANATION

UTILITY POWER-LOAD The utility power is connected to the LOAD via the KM contactor. This output energizes the KM contactor. The KG closes its auxiliary contact when it is open. In this way, the neutral line supplies the KM coil. The relay output that drives the KM output features normally closed contacts. By doing so, the controller gives priority to UTILITY POWER in case the ATS controller is damaged or without supply. The user will not suffer unexpected power failures if the UTILITY POWER is healthy. The ATS controller energizes the KM output only in the "TRUE UTILITY POWER FAILURE" event. This prevents the panel from supplying the LOAD with improper electrical parameters. Once the KM is open, the auxiliary contacts KM will close. This action will enable the KG to connect the load to the generator.
THE MOTORIZED SWITCH-BASED DIAGRAM
The motorized changeover consists of a switch with three positions: "primary source," "OFF," and "secondary source." An electric motor drives the switch to move in each position.
The motorized changeover has several advantages. Firstly, it can manage big currents if compared with a contactor-changeover. Secondly, it does not require power to hold the position. Thirdly, it is a cheap and safe solution for high-power switching.
SETTING UP THE AUTOMATIC TRANSFER SWITCH CONTROLLER
The AUTOMATIC TRANSFER SWITCH controller features default settings for a 400V 3-phase system. You can program the controller on-site in a few minutes. The controller accepts single or tri-phase voltage for the utility power and generator. To drive the motor of the transfer switch connect the KM and KG outputs as indicated in the wiring diagram. The battery supplies the ATS controller electronic circuits. You can use the ATS controller for up to 1000kVA electrical system.
OFF-MODE
Push the button [OFF] of the ATS controller to enter the OFF mode. The OFF mode clears the fault alarms and allows you to read or program parameters.
The Display and LEDs are turned off and a dot on the display will blink slowly. Push one of the pushbuttons on the front panel to energize the display.
MANUAL MODE
The MANUAL mode allows manual control of the engine and circuit breakers. Push the [MAN] push button to select the MANUAL mode. Push the [START] push button of the ATS controller until the engine starts; the display indicates the message [. . . .] during the starting attempts or [! ! ! !] if preheat has been programmed.
When the engine is running, the green LED turns on.
To stop the engine, push the [STOP] push button of the ATS controller until the [StOP] message appears on the display. If the engine has already stopped, it is possible to reset the STOP sequence by pressing the [STOP] push button.
MANUAL CHANGEOVER
Select MANUAL mode. Start the engine, and wait for a voltage. Push the [ I ] (KG) push button of the ATS controller to close the Generator circuit breaker.
To transfer the Load to "UTILITY POWER", push the [I] (KM) push button (the [KG] will open). Push the [O] push button to open a Contactor. In manual mode, the CHANGEOVER timer lasts one second.
AUTO MODE
Push the [AUTO] push button of the ATS controller until the green LED illuminates. The engine starts when the Be242 detects a power outage. The Contactor of the "PRIMARY SOURCE" (KM) opens after the BREAKER timing. After the warm-up time, if the voltage and frequency are within the settings, the circuit breaker of the "SECONDARY SOURCE" (KG) will close.
If the UTILITY POWER is restored, the KG will open. The KM will close following a programmed changeover timing. The Engine will stop after cooling downtime. If the engine shuts down, the KM closes independently of the "UTILITY POWER" status if the [P.48] is [ON] (NFPA-110 mode), otherwise, the KM will close only if the UTILITY POWER is within programmed settings. In AUTO mode, the BE242 will periodically test the engine. You must set parameters [P.41] and [P.42]. During this test, the AUTO mode green LED will continue to blink. The Be242 controller starts and stops the engine according to programmed inputs.
TEST MODE
Push the [TEST] push button of the ATS controller until the green LED illuminates. The Be242 ATS controller starts the engine and transfers the load to the Generator if [P.17] is [on]. Select the AUTO or OFF mode to stop the engine. If you push the [STOP] push button when the ATS controller is in AUTO or TEST, the [Er.09] will energize. To clear the alarm, select the OFF mode.
SPECIFICATIONS
DC Supply: 5.5/30Vdc, 50/150mA
Protection: 500mA thermal fuse
Dimensions: 194 X 146 X 205
Panel Cut-out: Round 60mm
Operating temperature: -30 to +70 deg C
Humidity range: 8% up to 90%
Weight: 300 grams
Meets ECC 89/336, 89/392, 73/23, 93/68, IEC 68-2-6
Certification: CE
Display: 4 digits solid state
LED Indicators for all functions
12 Silver-Membrane-Type 100.000 actions life
Over 60 programmable adjustable settings
THE ATS CONTROLLER RELAY BOARD INTERFACE
Supply Voltage: 5.5-30Vdc, 50-150mA
Protection: internal 3A thermal fuse
Dimensions: 210 X 150 X 80 (mm)
Installation: DIN-RAIL
Temperature: -30 deg C up to +70 deg C.
Humidity: 5% up to 90%
Weight: 600 grams
Metts ECC 89/336, 89/392, 73/23, 93/68.
Certification: CE
DC Relay Outputs: 3A 30VDC.
AC Relay Outputs: 8A 250V AC
Output Fuses: 2A
Connectors: removable terminal blocks
Operating Vac: up to 600Vac
Overvoltage Voltage: 2KVac
CTs: up to 1000/5Aac
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