Wago APM [160-4000A] for Zaptec Pro

General description

On some charger installations the available power for charging depends on the overall main fuse load. In installation like an apartment complex the apartments must have power priority, while car-charging uses the excess power available. Since this excess power changes dynamically, this must be monitored, and communicated to the ZapCloud load-balancer to ensure that the main fuse is never overloaded due to car charging.
This document describes the main fuse current measurement solution.


The Wago PLC 750-8101 is a rail-mounted modular solution. With the 3-phase 750-495 measurement module the unit can perform advanced 3-phase voltage and current measurements. In addition the 750-600 block is required as an end module to terminate the module block.
This PLC is connected to Internet with standard RJ45 Ethernet plug. A second Ethernet plug can be used for directly connecting a maintenance computer or for extending the Ethernet connection to other permanent equipment.


For a complete 3-phase voltage and current measurement setup and 4 current sensor coils should be used. The 4th current sensor measuring on the Neutral wire is not used on installations with IT-grid and is optional for for TN-grid.
The voltage measurement are provided internally. The Rogowski coil sensors have a measurement range from 0-4000A. Due to increased uncertainty in the lower region, they should not be used for installations with max fuse less than 160 A.

Considerations during installation

  • The installation point requires Internet access through an Ethernet connection. By default the unit is configured with dynamically assigned IP-address. If necessary, a static IP-address can be configured.
  • The installation point must have sufficient space to place the IP67 Boks.
  • The installation point must allow attaching the current sensor coils around the individual wires L1, L2, L3 and N. Coil dimensions must be suitable for the installation point cable dimensions, and max sensor current rating must be larger than max main fuse current. If the main fuse is overloaded, the sensor must be able to measure the overload current. This is vital for performing diagnostics in case of overload.

The ID(Ethernet MAC address) of the PLC must be associated with the correct installation in ZapCloud. This information must be communicated to Zaptec support or configured under the Installation on the Zaptec portal web page(https://portal.zaptec.com/).

A. Installation of APM

  1. Connection:
    • APM comes pre-wired for a TN grid. When connecting to an IT grid, rewire according to Figure 1. 
    • Rogowski coils come in pre-defined lenghts and should not be modified.
    • Install Rogowski coils on the correct phase conductor according to the arrow and labeling. 
    • Use a 3-phase power cable along with the supplied quick connector to power up the APM.
  2. Connect the Ethernet cable with active internet connection to the WAGO APM (RJ45 plug: ETH1).
  3. Ensure that all Rogowski coils are installed on the correct phase conductor, in the right direction, and securely fastened.
  4. Ensure that the GREY function switch on the WAGO APM is in the upper position: RUN.
  5. Power up the WAGO APM.
  6. Check that the LED diode marked "USR" on the WAGO APM flashes green within 1-2 minutes. 
  • LED light description: USR diode 
  • GREEN: Status OK – WAGO APM is communicating with Zaptec Portal
  • ORANGE: Status – Check network connection – Attempting to establish first contact with Zaptec Portal
  • RED: Status – Offline – The unit has previously been online, but cannot establish contact with Zaptec Portal

    7. Contact Zaptec Support in your country for activation.


B. Contact Zaptec Support

Zaptec Support requires the following information to activate WAGO APM for Pro:

  1. Zaptec Portal installation name.
  2. MAC address for WAGO APM.
  3. Main fuse rating (A), to be entered into the Zaptec Portal installation.



Figure 1: Rewiring for the IT grid

The O2 cable running between N on the power supply and the N-terminal block, the latter connection must be moved to the terminal block for L2 or L3 to supply voltage to the power supply.


GREY function switch:                     

Set to the RUN position


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