transformer type 1

[Mefi01]

Hello friends,

Does the type of transformers ( Knan, onan etc) one can use matter depending on whether they will be placed inside or outside a substation ? could someone explain what the rule is on this.

thank you !

 

[waross]

ONAN Oil Cooled, Natural convection, Air cooled, Natural convection.
ONAF Oil Cooled, Natural convection, Air cooled, Forced convection.

Bill
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"Why not the best?"
Jimmy Carter

 

[prc]

All transformers are suitable for indoor or outdoor use. There are no separate standards for indoor/outdoor installation.

 

[rcw retired EE]

Fire codes and local authorities may determine which transformer types are allowed indoors or close to a critical facility. An oil filled transformer can be a fire hazard.

A KNAN transformer with a high fire point liquid is one solution where a transformer failure and fire is a concern.

 

[RRaghunath]

In 1980s, we had Silicone liquid filled transformers installed indoors. The flash point for the Silicone liquid was 340degreeC (if my memory serves me right). This liquid is also known to be fire resistant.
Now a days, these are not preferred and instead, we have natural ester or vegetable based fire resistant liquids available.
Silicone liquids or synthetic and have limited biodegradability and thus are not preferred environmentally.
Mineral oils that are widely used in transformers are not suitable for indoor use due to the low flash point and also because the fire can sustain once started.
'O' in ONAN refers to mineral oil and 'K' in KNAN refers to liquids with >300degC flash point (and thus suitable for indoor use).

Rompicherla Raghunath