A Technical earth is used in professional environments (Audio and Visual recording) where they must have a clean earth.
The reason is that with every building there are items such as fridges and freezers that when activated by their own controls send out interference down the mains and earth wires.
AC units / Fans / Large electric heaters / Hot water pumps / Large amplifiers / Large power supplies / TFT Computer monitors and TV monitors / Light Dimmers.
Some of these items will be in your studio, but as they will be on, they will not generate much nose. Just make sure you don’t turn things on or off when you’re recording!!
Even though most items have suppressors to dampen this, they still give out unwanted spikes that will end up in becoming audible via any sensitive audio device connected to the mains. They also become visible on TV sets and computers if they are big enough spikes.
So most professionals go to great lengths to make sure they have as much separation from the buildings ‘Dirty earth’ and do as much as possible to make sure that there earth is a ‘Clean earth’.
If you are building a building from scratch then the costs are not that great. It’s only if you are updating an exciting building.
The most import thing is that your earth has its own earth spike. This way you don’t end up connecting you clean earth to a dirty earth and defeating the whole object.
You need to make sure that anything that could be used as a power outlet for you equipment in on your technical earth and is totally isolated from the rest of the building.
- Mains sockets
- Metal dado
- Metal cable tray
- Metal conduct
- Basically anything metal must have an earth, so if you are going to be using it make sure it’s not connected to the buildings earth.
Make sure you explain this to your M&E contractors or electricians as they must earth bond everything, including the steel structure of the building. So you cannot have your metal cable trays or metal dado attached to the buildings metal.
You then have a central point for all you earths to come back to, kind of like star earth. You will need to have it all safety checked as this is a legal requirement. The larger the earth spike you put into the ground the better, also placing it in a damp area really helps.