Power Line Communication (PLC)

Zaptec Pro chargers can use Wi-Fi, LTE, or PLC networks for communication. In this article, you can learn more about how to use and set up PLC networks. 

Click here to download installation instructions. 

 

What is PLC? 

Power line communication (PLC) is a communication method that uses the local power grid (230V) to provide an internet connection to other Power line devices (charging stations). The PLC module is thus a communication converter, which converts wired internet connection (network cable) to the internet over the local power grid (power line). This removes the need to run network cabling to each charger.

 

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Click here to watch how this works in theory. Note that the video eFixx uses a standard domestic PLC adapter; Zaptec recommends that you use the Zaptec-supplied DIN-rail PLC module for maximum reliability.

 

Installation 

The PLC module is mounted on a DIN rail. It requires a connection to the main power cabling and a standard ethernet. It is recommended to install a 10A fuse before the PLC module. The module is usually mounted after a 63A course, but the connection terminals are 1.5-2.5 mm2. This also simplifies any troubleshooting and restart of the PLC module.

To ensure reliability:

  • Minimum one PLC module for each circuit

  • Each PLC module can support up to ~30 chargers

  • Install PLC module close to charging stations

  • Remove/isolate noise sources from network

  • Only use connection terminals marked L1-N-PE

  • Ensure the protective earth (PE) is in good condition 


We recommend installing the PLC module in an enclosure close to charging stations. This is because long distance can impact the signal strength. The cable length must never be more than  90 meters. However, the recommended distance will vary based on other factors, such as grid type, number of chargers, and noise from the power grid.  E.g. Compared to in TN systems, a IT system requires a shorter distance.

 

Charging stations communicate on PLC over L1 and N. PLC module should therefore not be connected as 3phase. It is important that the phase order is the same on the entire charging system. Connecting the PLC 3 phase or using L2 or L3 will extend the cable length which can reduce the signal strength.

 

 

        Connection TN system                                                      Connection IT system 

Screenshot_2023-01-10_at_22.52.58.png             Screenshot_2023-01-10_at_22.59.21.png

 

 

 

Configure the PLC module

After the PLC is mounted you will need to connect the charging stations to the PLC network. 

If you purchased the module after Nov. 2019 it comes pre-encrypted with QR code, but if you purchased it before Nov. 2019 it is without encryption and QR code. 

 

After November 2019:

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Before November 2019: 

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Regardless of which module it is, you will need to use the Zaptec app for configuration. 

Follow the steps below to connect the charging station to the PLC modul with QR code: 

  1. From Home, tap the three-dot icon at the top-right
  2. Tap Configure products and use the PIN code to connect to the charger via Bluetooth
  3. Scroll down to Network Settings
  4. Tap Configure PLC
  5. Tap Scan network name and use the camera to scan the QR code on the PLC module. iPhone users can upload images from gallery
  6. Tap Save to connect to network

Please note: These steps are repeated for each charging station to be connected to the PLC module.

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Video tutorial for how to configure PLC networking on a Zaptec Pro:

 

Use existing network key to add another charging station

PLC module purchased before Nov. 2019 is without encryption and without QR code

 

Copy network key from an online charging station

1. From Home, tap the three dot icon at the top-right

2. Tap Configure product and wait for the app find the charging stations via Bluetooth

4. Scroll down to Network settings and tap Configure PLC and copy the network key

5. Then follow the same procedure on the new charger and paste the network key in the last paragraph under Set network key. Remember to tap Save

 

 

Indicator light 

 

 mceclip1.png Green  PLC is connected to power 
 mceclip1.png No Light PLC is not connected to power
 mceclip2.png Red PLC communicates with charger(s)
 mceclip2.png Green  PLC is not communicating with other units on the PLC network. This could be because the chargers are not encrypted with the same encryption key as PLC  
 mceclip3.png Green  PLC is connected to network router 
mceclip3.png No Light  

PLC is not connected to open port on router. Even though it is communicating with router, it does not mean it has access to the internet.

 

Troubleshooting

Factors that can affect the signal strength of the PLC network:

 

1. Total length of cable

Cable length has a direct effect on the signal strength of the charging stations.

In addition to having one PLC per cable run / course, it is important to consider the location of the PLC module.

If the supply from the switchboard is located far away from the charging system, the PLC module should be placed closer to the charging stations.

The charging stations communicate with the PLC only between L1 + N + PE.

Connection on the L2 and L3 terminals will lead to increased cable length the devices are trying to communicate over.

 

2. Number of connected devices

A PLC module has a limit on the number of devices it can communicate with. Exceeding this number will lead to unstable communication over the PLC. It is therefore important to isolate PLC communication on each course by encrypting the PLC module and associated charging stations.

General recommendation is 30 charging stations per PLC module. 

Minimum one PLC unit per cable run / course.

 

3. Grounding conditions

PLC communication uses the ground connection for positioning the frequency range.

Without a ground connection, the PLC communication range will be significantly reduced.

If the ground connection is insufficient or affected by external factors like ground faults, this may result in the PLC not being able to maintain sufficient signal quality for stable communication.

 

4. Local power outages

Noise from external sources, like frequency converters, can be difficult to map but this can be limited by installing a filter before the PLC module.

 

 

 

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