air con inverter, static noise

Anything that don't have special filtering/power conditioning (read motors->blenders, a/c systems...), connected to the mains, that produce spikes, harmonics, or something else, will interfere, specially with analog audio and image applications.

A good example is, try to watch an ond analog TV while using a blender.

It will be interesting to hear what Steve comes back with.

Guys

Still no further as yet. Things move slow as there are many different contractors and consultants involved in this project. At this time it is me asking all the questions to the others involved and they appear to be a little concerned to the depth of my knowledge on the subject. I have to thank you all for your help with this. you have been providing me with all the answers, and questions that I require. I had the impression that the finger was pointing at us the Air Con Installer, But now the finger is pointing at the right people, the consultants who specified the equipment and designed the studio and its layout. This problem will be resolved as soon as. It will most likely be us who will carry out the necessary works to remedy this problem and I will post the results.

Thanks again Guys....

It sounds like people are playing the blame game which is stopping them from working together.

I think all parties should improve the shielding for the equipment they're responsible for.

Thanks Guys...

Your help and info has been helpful with this the problem turned out to be an inadequate power supply to the building. There is two types of power supply that get installed by the electricity board and grounding was the issue.
The supply that has been installed had an earth that has been split from the neutral. The power supply that would have been best would have been a standard earth rod drilled into the ground. Various earth rods have now been drilled in to the ground and this has eliminated the noise. Much time has been expended by us on site changing and rerouting cables. Then one day whilst the power was off at the air con the noise returned, someone plugged in a vacuum cleaner. The studio sound engineer apologised to us as he was convinced the problem was only generated when the air con started.

The studio electric's and grounding issues was mentioned by you guys at the beginning, and was something I mentioned to the engineer from the start. Unfortunately at the time he thought he knew best.