Air Supply

Without seeing the drawings, one possibility is that it won't work without it.

They appear to have released another batch of Anonymous Posters from the home.

Quite possible the panel is situated in Class 1 , Div 2, So Panel purging is to done its a way of protection of electrical device in Hazardous area

or

Vortex cooling arrangement is done to prevent electronics card getting exposed to high ambient temperature

Regards

Jose

Paragraph 1: if only the original poster would state whether or not this is an Ex p installation! However, Ex p only requires purging with air ducted in from a safe area to a slight overpressure inside the enclosure; nitrogen is not required.

with so little information provided my guess is that nitrogen is used in the panel for something (gas sampling perhaps).

Either that or the installer or designer is totally incompetent.

Ooooh, how about a panel fire suppression system.

What exactly does the panel do.

Are you still there?

Without knowing the area classification or the design it is hard to say for sure.

Is there to be a Nitrogen purge in the cabinet and instrument air to run the instruments.

This is a fairly common arrangement, where the Nitrogen can be easily turned off when you have to work in the cabinet.

If the plan is to use the Nitrogen as instrument air then there is a real danger of creating a bad atmosphere in the cabinet as all pneumatic instruments need to vent or bleed gas.

Maybe instrument air is to be the primary source and the Nitrogen is to be a backup supply.

More details are almost always needed to get better answers.

Perhaps for the same reason that electricity might be connected, so that the panel will perform its intended purpose (whatever that might be).

Nitrogen purge systems are used when there is no practical way to get dry instrument air to a panel for purging, and the box is tightly sealed so as to not leak (much) and is not opened except for emergency repairs. The N₂ is often just a canister attached to the enclosure or stored near by.

N₂ purging is also a good choice for optoelectronic based controls and systems, it prevents moisture from getting in or on the instruments, especially in high altitudes where the low atmospheric pressure lowers the dew point significantly.

Argon gas is used the same way as well.