Jump to content

Earth Questions


Jay-Dee
 Share

Recommended Posts

Hello all

Two questions to help my understanding as I am seeing conflicting opinions in various posts...

The earth from the AC Out / Inverter DB... Can this be connected to the primary Eskom supply DB earth and is this bridge by the inverter (Axpert King 5K... AC in earth goes directly into the inverter where the AC out is connected to the casing)?    If not, where should it be connected to?

I will soon have 3 separately located banks of Solar Panels on difference sections of my house, do each of these require their own earth spike or can they all be connected to the same spike? (wanting to avoid having multiple spikes around the house).

I am having my installation expanded on Thursday and wanted to get opinions before they arrive as to what is the right way as we are using an independent engineer to sign off the new COC and really dont want them going back and forth.

Thanks in advance

Link to comment
Share on other sites

All earths are always interconnected and should not be interrupted. The AC-in, out, etc will have their earths connected together. In other words, this is already connected to the earth provided by your supplier (for a TN-C-S connection, there will be an earth spike on your premises, and for a TN-S setup, the earth is at the transformer and you have a separate earth going back all the way to the transformer).

The advice I've been given is to earth everything to the same earth point. The earth provided by the supplier is usually of excellent quality and better than anything you can sink (unless you sink several spikes to get the resistance low enough), so in most cases, if it shows a low earth impedance, you can use it for everything.

I'm not an electrician though, so confirm with one 🙂

 

Link to comment
Share on other sites

The earthing of these systems is fairly straightforward I reckon. But ensure your house insurance small print is complied with (if any)

The relationship between earth of the live and neutral of the inverter output is a bit more tricky. With normal transformer inverters the supply from the inverter is isolated from the input. This means it can 'float'. With switched mode PSUs there is a MOV connected between the primary and secondary of the transformer to limit the possible difference in voltage.

I've noticed that systems that the user can switch between the inverter and mains they install a 2 pole (3 position?) switch. (This is to manage the voltage differences to earth I believe)

Link to comment
Share on other sites

4 minutes ago, Richard Mackay said:

The earthing of these systems is fairly straightforward I reckon. But ensure your house insurance small print is complied with (if any)

The relationship between earth of the live and neutral of the inverter output is a bit more tricky. With normal transformer inverters the supply from the inverter is isolated from the input. This means it can 'float'. With switched mode PSUs there is a MOV connected between the primary and secondary of the transformer to limit the possible difference in voltage.

I've noticed that systems that the user can switch between the inverter and mains they install a 2 pole (3 position?) switch. (This is to manage the voltage differences to earth I believe)

Thank you.  My insurance is very strict on the requirement of a COC and registration with COCT... I am already registered from my previous installation and just need to get the COC updated with the expansion.

I do currently have a change over switch which works well and would highly recommend (if not a requirement) for all systems as it allows you to keep the house happy should any work need to be done on the system (amongst other vital reasons)

Link to comment
Share on other sites

54 minutes ago, Jay-Dee said:

I do currently have a change over switch which works well and would highly recommend (if not a requirement) for all systems as it allows you to keep the house happy should any work need to be done on the system (amongst other vital reasons)

Please post a pic of this switch..

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...