ONAN or ONAF, What is the Difference?

The first letter designates the internal cooling medium in contact with the windings.

* O= mineral oil or synthetic insulation fluid with a fire point 300C

* K = insulating fluid with a fire point > 300C

* L = insulating liquid with no me3asurable fire point.

The second letter designates the circulation mechanism for internal cooling medium

* N = Natural convection flow through cooling equipment and in windings

* F = Forced circulation through cooling equipment and natural convention flow in the windings (also called "directed flow")

* D = Forced circulation through cooling equipment, directed from the cooling equipment into at least the main windings

The third letter designates external cooling medium

* A = Air

* W = Water

The fourth letter designates the circulation mechanism for the external cooling medium.

* N = Natural convection

* F = Forced circulation (Fans (air cooling) , pumps (water cooling))

For example: ONAN designates an oil filled unit that has natural convection flow in the tank and utilizes natural air convection cooling externally.

If this transformer has fans added for forced air externally, the designation would be ONAF.

A transformer that has natural convection cooling as a base rating and an elevated rating when fans were added later, would be designated as ONAN/ONAF.

High fire point fluids use the designation of "K" for fluid type. Thus a naturally cooled high fire point fluid would be KNAN and the same unit with fans would be KNAF.

ONAN or ONAF, What is the Difference?

By: Mike Dickinson

POST COMMENT

Making The Right Choice From Awnings For Sale CBT Counselling - How It Works Buy Mens Bracelets How To Make A Pinata? Best Cities to be a Psychologist Extenze Works: Cure Erectile Dysfunction Permanently! HTC Desire HD Deals - Be worry free of the expenses Make A Camp Table - Avoid Spending Hundreds ! 5 Steps to Keep Good Mentality of the Classic Work Social Bookmark Best Source Of Traffic How to improve your concentration Vitamin C Can Bring Back Lost Looks How to build the perfect decking