ANAF or ONAN transformers

[davva]

Two questions:-

1. I have only ever come across ANAF transformers fitted indoors. Are they ever used outdoors, particularly if it is a high ambient temperature environment?

2. What is the approximate ratio in size difference between a ANAF and ONAN 8MVA transformer?

 

[TMB64]

1. I have seen them used outdoors in a 3-phase 1.5 MVA application, this was in Africa. The temp was aproximatly 90 degrees F. The units were produced by Crompton Greaves I believe.

2. The 1.5 ANAF unit was a 3 phase cast coil design with fans on the frame that circulated air through the coils. They were very compact units, I'm not sure if anyone produces a cast coils ANAF unit at 8MVA. There is a chinese company that makes cast coil units in larger sizes, I can't recall the company name, but the model line is SCB10 Resin Dry Type Transformers. If you google that, there are a lot of results to review. The 1.5MVA cast coil units I have dealt with weres about 30% smaller than the equivlant oil insulayted unit. I hope this helps.