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



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