Check Grid CT / Installation Limit / Grid CT Lost

Check Grid CT / Installation Limit / Grid CT Lost

Overview

The error message Check Grid CT / Installation Limit / Grid CT Lost.  This error shows it's often one of the reasons below for the fault.


More than one CT is set to "Grid"

Only one CT (or set of three CTs in a three-phase system) should be set to the grid. If there are multiple grid CTs fitted then this will confuse the system (there can only be one physical grid connection to the property!).

If multiple CTs are set to the grid then it's likely that one of these will be reading zero and this is what is then set as the grid reading, even if one of the other CTs is reading the correct values.

You can easily see if this is the case by going to a device and checking the menus shown below.

The Tilde symbol (~) confirms that this device has a Grid CT configured (there should be only one).

To remove this once you have identified which device does have the Grid CT you go to the following men shown below:

Change GRID via the scrolling menu to NONE. This will then remove the error. 


The Grid CT has not been fitted

To track and measure the power flow to/from the grid a grid CT must be fitted.

If this is missing, not connected or there is no grid CT setup then the myenergi devices will not be able to divert excess generation or display power in the app.

You can easily see if this is the case by going to a device and checking the menus shown below.

The Tilde symbol (~) confirms that this device has a Grid CT configured (there should be only one). As you can see in this example there is none.

Occasionally we come across systems (normally zappis) where the installer has not fitted the grid CT because they do not realise how important it is.


The Grid CT is in the wrong place

The CT must be installed so that it measures all the power flowing into/out of the property.

Below is a diagram from our manual that confirms the correct location for a Grid CT. 

The best place for the CT is on the live cable that comes from the electricity meter. Real-world examples below: 

It is common (particularly when installing EV chargers such as zappi) to split the supply at this point and install a new consumer unit (fuse box).  The cable is split by using a "Henley Block".


What does the CT look like?

The Myenergi CT looks like this (below). The arrow always needs to point inwards to the house systems not back to the power source, 

 


If you require further assistance please create a ticket to our support team here



    • Related Articles

    • Why does my device keep losing Wi-Fi connection? (Wi-Fi Strength Check)

      Overview Wi-Fi strength, measured in dBm (decibel milliwatts), indicates the power level of the signal received by your device from a Wi-Fi router or access point. dBm is a logarithmic unit used to express power relative to 1 milliwatt (mW). The ...
    • How to check the IP address of the server (zappi 2)

      Overview Although the latest versions of zappi, eddi and libbi all come with built-in WiFi and Ethernet, the older models only use a radio link to communicate with each other and the myenergi hub. Where the radio link is weak it is now possible to ...
    • Zappi v2 Navigation Menus

      Zappi Navigation Menus Main Menu Options Description Charge Log Today Log of charge sessions Yesterday Week Month Year Total Custom Date Event Log Today Log of events Yesterday Week Custom Date WCS Readings READINGS 1/9 Status: Mode: Current status ...
    • PE Fault

      Overview Within Zappi the PE check is an advanced feature in the zappi which is not provided by most other EV chargers. It uses the impedance of the supply back to the primary transformer to confirm the continuity of the earth conductor so in some ...
    • Terms and Conditions

      Hall Power Limited Terms and Conditions: Subscription for charging electric vehicles Valid as of 9th May 2019 Trading as ePower, Hall Power Limited offers electric vehicle charging equipment and expert services related to charging electric vehicles, ...