Table of Contents

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Charging Station Dimensions

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Figure 1: INCH DUO dimensions

Additional considerations of dimensions:

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• Screwdriver,

• Hex screwdriver (if charging station without key lock on maintenance doors),

• Utility knife,

• Self-adjusting crimping pliers for cables' end sleeves,

• Wire trippers and

• Cable rippers.

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Figure 2: Equipment used for the installation of charging station

2. PRODUCT DESCRIPTION

The Etrel’s public charging station INCH DUO is highly configurable and can be tailored to the client’s specific needs. It allows simultaneous charging of two vehicles with power of up to 2 x 22,08 kW and is equipped with standard Type 2 sockets (EN 61851 or EN 62196-2).

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1. Grid connection of the charging station, which contains terminals for all supply wires (L1, L2, L3, N and PE).

2. Energy meters for each socket. For normal functioning of the station, a working communication connection between the main station controller and the energy meters is required.

3. Differential and overcurrent protection of each socket.

4. Module for communication with electric vehicle (compliant with the IEC 61851 standard), socket voltage monitoring components, socket contactors.

5. Main station controller with RFID reader, RFID antenna and LCD display, control circuit power supply, and communication modules (Ethernet or GPRS router).

Figure 3: Arrangement of equipment inside the station

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Base Specifications

• Input: 2x230/400V~; 3W+N+PE; 50/60 Hz; 32 A max.

• Output: 2x230/400V~; 3W+N+PE; 50/60 Hz; 32 A max.

• Maximum charging power: 2 x 22 kW (3-phase)

• Device power consumption:

  • From 5 W, depending on the actual configuration.

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Charger supports connecting four digital inputs and one digital output. Inputs and output are operating on 12 VDC, and maximal allowed load is 100 mA. Check pinout on the image below.

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Figure 4: Pins of connector for digital inputs and output

The use and logic of these digital input and outputs is settable via web interface of the charging station.

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In the following table, the installation method can be checked for the minimum cable cross-section when connecting one INCH DUO charging station. These values ​​apply for copper conductors with XLPE insulation at reference air temperature of 35 ° C. For installation of cables in the ground, temperature of the ground is set as 25 ° C and soil thermal resistivity as 2.5 K*m/W. Charging current of 64 A is being considered.

Table 1: Minimum cable cross-section for continuous operating current of 64 A.

	A1 - Insulated single core conductors in conduit in a thermally insulated wall A2 - Multicore cable in conduit in a thermally insulated wall This method also applies to single core or multicore cables installed directly in a thermally insulated wall (use methods A1 and A2 respectively), conductors installed in mouldings, architraves and window frames.	A1, A2: 16 mm2
	B1 - Insulated single core conductors in conduit on a wall B2 - Multicore cable in conduit on a wall This method applies when a conduit is installed inside a wall, against a wall or spaced less than 0.3 x D (overall diameter of the cable) from the wall. Method B also applies for cables installed in trunking / cable duct against a wall or suspended from a wall and cables installed in building cavities.	B1, B2: 16 mm2
	C - Single core or multi-core cable on a wooden wall This method also applies to cables fixed directly to walls or ceilings, suspended from ceilings, installed on unperforated cable trays (run horizontally or vertically), and installed directly in a masonry wall (with thermal resistivity less than 2 K·m/W).	C: 10 mm2
	D1 - Multicore or single core cables installed in conduit buried in the ground D2 - Multicore or single core cables buried directly in the ground	D1, D2: 16 mm2
	E - Multicore cable in free-air This method applies to cables installed on cable ladder, perforated cable tray or cleats provided that the cable is spaced more than 0.3 x D (overall diameter of the cable) from the wall. Note that cables installed on unperforated cable trays are classified under Method C.	E: 10 mm2
	F - Single core cables touching in free-air This method applies to cables installed on cable ladder, perforated cable tray or cleats provided that the cable is spaced more than 0.3 x D (overall diameter of the cable) from the wall. Note that cables installed on unperforated cable trays are classified under Method C.	F: 25 mm2
	G - Single-core cables laid flat and spaced in free-air This method applies to cables installed on cable ladder, perforated cable tray or cleats provided that the cable is spaced more than 0.3 x D (overall diameter of the cable) from the wall and with at least 1 x D spacings between cables. Note that cables installed on unperforated cable trays are classified under Method C. This method also applies to cables installed in air supported by insulators.	G: 25 mm2

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The length of the conductors and charging current are major factors determining the adequacy of cables cross-section, however voltage drop occurs on other components or devices as well. Because of it, some reserve should be considered when selecting cables cross-section.

Table 2: Voltage drop in conductors with 10 mm² cable cross-section and charging current of 64 A.

Table 3: Voltage drop in conductors with 16 mm² cable cross-section and charging current of 64 A.

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Lower voltage drop also means that the power losses of charging process will be lower. The life cycle assessment and calculation of benefit of using cables with larger cross-section could help mitigate the higher cost of investment.

Table 4: Voltage drop in conductors with 25 mm² cable cross-section and charging current of 64 A.

Table 5: Voltage drop in conductors with 35 mm² cable cross-section and charging current of 64 A.

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When the user connects EV to charger, and prior to beginning of charging, the charger determines the current available for charging as the difference between the rated current of the main fuse (reduced by a safety margin that can be pre-set by the user via charger’s web interface) and the last measurement received from Load guard.

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Figure 5: Use of additional consumption data to prevent overload

When there is local production of energy present at the location (e.g., photovoltaics), the available charging current can be higher, and the use of Load Guard make possible to always charge with maximum available current.

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Figure 6: Use of additional consumption and production data to prevent overload

4. Dimensioning of a cluster

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Power cables of the charging stations are connected to the common point (electrical cabinet in the following figure).

Figure 7: Cluster cabling route for multiple charging stations - star network topology

Power cables Point to Point Network Topology

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In case that Point-to-Point communication is needed for the power supply, all INCH Duo’s of the cluster with exclusion of the last one, should be equipped with double terminal clamps.

Figure 8: Cluster cabling route - point to point network topology (daisy chain)

Power cables Hybrid Network Topology

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All the charging stations of the cluster need to be connected to the network. The communication cables should follow star network topology. Point-to-Point wiring of communication cables is not fully supported yet. When needed all INCH Duo’s of the cluster should be equipped with router.

Table 6: Power cables installation method

	A1 - Insulated single core conductors in conduit in a thermally insulated wall A2 - Multicore cable in conduit in a thermally insulated wall This method also applies to single core or multicore cables installed directly in a thermally insulated wall (use methods A1 and A2 respectively), conductors installed in mouldings, architraves, and window frames.
	B1 - Insulated single core conductors in conduit on a wall B2 - Multicore cable in conduit on a wall This method applies when a conduit is installed inside a wall, against a wall or spaced less than 0.3 x D (overall diameter of the cable) from the wall. Method B also applies for cables installed in trunking / cable duct against a wall or suspended from a wall and cables installed in building cavities.
	C - Single core or multi-core cable on a wooden wall This method also applies to cables fixed directly to walls or ceilings, suspended from ceilings, installed on unperforated cable trays (run horizontally or vertically), and installed directly in a masonry wall (with thermal resistivity less than 2 K·m/W).
	D1 - Multicore or single core cables installed in conduit buried in the ground D2 - Multicore or single core cables buried directly in the ground
	E - Multicore cable in free-air This method applies to cables installed on cable ladder, perforated cable tray or cleats provided that the cable is spaced more than 0.3 x D (overall diameter of the cable) from the wall. Note that cables installed on unperforated cable trays are classified under Method C.
	F - Single core cables touching in free-air This method applies to cables installed on cable ladder, perforated cable tray or cleats provided that the cable is spaced more than 0.3 x D (overall diameter of the cable) from the wall. Note that cables installed on unperforated cable trays are classified under Method C.
	G - Single-core cables laid flat and spaced in free-air This method applies to cables installed on cable ladder, perforated cable tray or cleats provided that the cable is spaced more than 0.3 x D (overall diameter of the cable) from the wall and with at least 1 x D spacings between cables. Note that cables installed on unperforated cable trays are classified under Method C. This method also applies to cables installed in air supported by insulators.

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The currents presented in the following table require additional considerations from the electrical works planning view, which should be determined in the electrical project. It is possible, that high charging current would require implementation of bus-bar systems and/or possible installation of power transformers and/or additional requirements from the view of electrical safety and documentation preparation.

Table 7: Considering maximal current in case of clusters

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Almost all vehicles require minimally 6 A of charging current. Considering that there are some vehicles that require higher minimal charging current, some reserve to the numbers in the following table should be added to ensure all connected vehicles can charge simultaneously.

Table 8: Considering minimal current in case of clusters (three-phase wiring)

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• Three-phase system with copper conductors with XLPE insulation

• Ambient temperature 35 °C

• Ground temperature 25 °C

• Thermal resistivity of the soil 2,5 K·m/W

Table 9: Minimal cables cross-sections under specified conditions (1/2)

Table 10: Minimal cables cross-sections under specified conditions (2/2)

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Voltage drop in the power cable is proportional to the current of the load. When installing two INCH DUO charging stations, also voltage drops are twice as high as in case of one INCH DUO without considering any additional elements.

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Figure 9: Cluster cabling route length

The voltage drop presented in the tables are calculated for single-phase and three-phase connection. Although the connection of INCH DUO is almost always three-phase, using values of voltage drop in single-phase can represent beneficial reserve when planning the correct cable cross-section.

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Table 12: Voltage drop in conductors with 50 mm² cable cross-section and charging current of 128 A.

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For example, looking at the table determining minimal cross-section of cables for maximal continuous current of 320 A, depending on the installation method, either 70 mm² (Method G) or 150 mm² (Method C) cables could be used when connecting 5 INCH DUO charging stations with maximum charging current available. Reviewing the selection of the cable with consideration of voltage drop, shows that allowable distance of conductors is a lot lower than if selecting higher cable cross-section.

Table 13: Voltage drop in conductors with 70 mm² cable cross-section and charging current of 320 A.

Table 14: Voltage drop in conductors with 95 mm² cable cross-section and charging current of 320 A.

Table 15: Voltage drop in conductors with 120 mm² cable cross-section and charging current of 320 A.

Table 16: Voltage drop in conductors with 150 mm² cable cross-section and charging current of 320 A.

Table 17: Voltage drop in conductors with 240 mm² cable cross-section and charging current of 320 A.

Table 18: Voltage drop in conductors with 300 mm² cable cross-section and charging current of 320 A.

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Although the short circuit withstand criterion must be evaluated when dimensioning cables cross-section, in practice requirements of the first two criteria are stricter (continuous operating current and voltage drop).

Table 19: Minimum cable cross-section able to withstand specified short circuit

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Keep in mind that if the cables cross-section changes (e.g., in first junction box, from cross-section used on L1 to cross-section used on L2) and is lowered to level that cannot sustain the full current, the over-current protection element should be installed.

Figure 10: Example of INCH DUO connection – standard configuration

Maximal continuous current of the cluster

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• Voltage drop in cable at L1

Table 20: Voltage drop in conductors with 400 mm² cable cross-section and charging current of 960 A.

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The case presented in the following figure is possible only with double clamp terminals installed in all INCH DUO charging stations, instead of the last one of the power lines (three INCH DUOs that are completely right on the figure). The cable cross-sections must be determined in accordance with all three criteria.

Figure 11: Example of INCH DUO connection – use of double terminal clamps

Maximal continuous current of the cluster

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Case 3: Power Cables for Cluster of 15 INCH DUO in Expanded Point to Point Network

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Figure 12: Example of INCH DUO connection – use of double terminal clamps

The figure presented above is showing possible selected configuration, after reviewing Case 1 and 2. It could be more expensive to install three main routes of cables, however using more conductive material (copper) will lower the voltage drop of installation (and with it the power losses).

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After the installation pipe is built into the concrete foundation, it is used for cabling and connection of the charging station. The concrete foundation must be left to dry for at least two days before the cables can be inserted in the installation pipe.

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Figure 13: Placing of installation pipe and insertion of cables

Supply cables are routed through the underground anchoring structure with the use of installation pipe as shown in the figure above. The exact way of cable routing depends on the type of cables used and their diameter (which is determined in the project documentation). When dealing with cables with larger diameters, their bending radius must be considered.

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Remove 20 mm of insulation from all cables and attach and compress the appropriate crimp tubes on all cables. To prevent cables from getting in the way of mounting the charging station, twist them into an installation pipe. Length of cables on the other side of the gland should be:

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Figure 14: Preparation of cables

Power Supply Compartment

The power and communication cables are routed through the foundation after the casing of the charging station is installed. Care must be taken not to damage the equipment inside the charging station.

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A three-phase 5-wire power cable is used for the connection, based on the type of connection. Standard terminals enable connection of cables of up to 50 mm² diameter. Customization with additional clamps is possible and they enable double connection up to 95 mm².

Figure 15: Overview of the power supply compartment

The configuration of the charging station depends also on the type of grid connection. The charging station is usually connected to an existing installation.

Figure 16: Power supply compartment cover

To enable access to the power supply compartment first unscrew and remove the protective cover.

There is a sticker on main connection element showing the correct designation of phases and neutral conductor. Remove the sticker and make sure that screws inside the main miniature circuit breaker (MCB) in which wires will be connected are unscrewed.

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Figure 17: Connection of charging station to the power grid

To the main circuit breaker of the charging station, three supply phase conductors are connected in right order of phases. Normally, this would mean connecting from left to right, phase 1 (L1, brown), phase 2 (L2, black), phase 3 (L3, grey).

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Figure 18: Example of the power supply compartment additional components

The neutral conductor (N, blue) must be connected to the neutral pole of miniature circuit breaker and PE conductor (PE, yellow/green) to the earthing clamp.

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The software configuration must be properly made in charging station web interface and in the charging management platform (e.g., Etrel Ocean).

Figure 19: Connecting the cables

Connection of the Protective Earthing (PE)

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1. Cut off the network cable to the appropriate length to reach the Ethernet connector. Do not make the wire routing too tight or too loose.

2. Use the network cable pliers to attach the RJ45 connector to the network cable.

3. Insert the RJ45 connector into the Ethernet connector.

4. If a network switch is installed in the station, the UTP cable is connected to its Port 4 (for means of clustering or DLMS communication with the meters). When there is no network switch installed, the network cable is connected directly to the Ethernet port of the main controller of the charging station, located on the station's doors. Ethernet port is located on the lower left side.

Figure 20: Connecting the UTP cables

Finishing Work

Before closing the station, check the condition of the over-current protection elements and the residual current devices. Switches must be set to ON position.

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Check the condition of all four elements. Close the charging station door and lock it. Connect the charging station to the power supply in the electrical cabinet. Turn on the power supply where the station is connected.

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Figure 21: Positions of MCBs and RCDs

The hole in the bottom of the charging station should be filled with polyurethane foam filler (or similar material).

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Continuity measurement should be performed for protective conductors, including conductors in the main and additional equipotential. Measurement will have to be made between PE terminal of charging station’s socket and inlet PE conductor. If the charging station is equipped with cable, the measurement should be made between PE conductor of the cable plug and inlet PE conductor.

Image RemovedImage Added

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The use of instrument, with option of measuring at higher current than 200 mA increases the accuracy of the measurement. The method of measurement is shown in the figure:

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Figure 22: Continuity measurement

Continuity of the wire is considered to be met if the connection resistance does not exceed the value of 2 Ω.

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Insulation resistance, measured at a test voltage of 250 V d. c. is satisfactory if its value is not less than 1 MΩ.

Table 1: Insulation resistance measurement conditions

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The standard values of insulation resistance measurement, shown in the table below are not applicable.

Table 2: Standard values ​​of insulation resistance measurement are not applicable

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The effectiveness of the protection measure can be considered satisfied if the trip occurs at a certain value of the leakage current and within a certain time.

Table 3: Type AC and A residual current circuit breakers without built-in overcurrent protection - normalized switching time values

Table 4: Type B RCDs - normalized tripping time values for residual currents in rectifier circuits and for smoothed residual current

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• Z_S is the fault loop impedance,

• I_a is a current that causes an automatic power cut-off within the time specified in the table below,

• U_o is the rated AC or DC voltage with respect to earth.

Table 5: Maximum switch-off times

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To avoid possible risks due to currents caused by potential differences between neutral and earth, the system should be switched off during connection and disconnection. It should be noted that the values of resistance obtained using Method C3 will typically be higher than those obtained using Method C1 because of the earth loop measurement.

Figure 25. Measurement of earth electrode resistance using current clamps

2-point (dead earth) method

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If authentication is needed, select the type of authentication that will be used to authorize and continue with the charging session.

Insert PIN code

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Figure 26: Insert PIN code

b) Use mobile app to authenticate

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Figure 27: Insert charging station's EVSE code

Either type the code of the station to the mobile app or scan QR code with mobile.

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After the successful authorization, the screen with the description to connect the cable is shown.

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Figure 28: Connect the cable to charging station and EV

If the cable is connected before the authorization this screen will be left out and after the authorization next screen “Waiting for vehicle to respond” will be shown. When the cable is connected charging station will start charging as soon as EV responds.

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Figure 29: Charging station is waiting for EV to responds and starts charging

Step 4: Departure time input

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When the departure time is set, or default setting is let through charging data will be shown. What charging information is presented depends on the settings of Web interface.

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Figure 30: Example of shown energy on the LCD screen

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Figure 31: Display of charging time

Check Status of the Charging Station

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Charging station can be stopped locally or remotely.

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Figure 32: Current session information displayed in the web interface

Locally

Ending the session can be performed with the same authorization method as for starting a session (using RFID cards, mobile application, PIN code) and removing the plug from the charging sockets or, in case of configuration of charging station without authorization permissions, by unplugging the charging cable.

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Stop of charging session can be done remotely with the use of Web interface.

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Figure 33: Confirmation window to stop the charging session using web interface

Paying Procedure in Case of Cluster of Charging Stations

It is possible to implement several INCH DUO charging stations into the same cluster and having the paying terminal installed only on one of them. In this case, the LCD display will lead the customer, on which charging station it is possible to pay for the charging.

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Figure 34: Paying procedure in case of clusters, notification at charging station where charging was made

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Figure 35: Paying procedure in case of clusters, input of designation of charging station where charging was performed at another charging station with paying terminal

8. CONTACT INFORMATION

Technical support department

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