[Amps] Transformer Calcs

[Dr. David Kirkby]

On 06/10/10 06:04 PM, Bill, W6WRT wrote:
> ORIGINAL MESSAGE:
>
> On Wed, 9 Jun 2010 16:22:11 +0200, Andre Goldschagg
> <totiranger at gmail.com>  wrote:
>
>> Is there a standard formula to use to calculate the KVA rating of a
>> transformer?
>
> REPLY:
>
> This may sound like I'm joking, but I'm not:  When running
> continuously, if the transformer runs too hot to touch, it is
> overloaded. Heat is the enemy of the insulation and will deteriorate
> it over time, leading to failure.
>
> 73, Bill W6WRT

Personally I would have thought just because a transformer is not too hot to 
touch, it would not be safe to assume it is ok. I've run many transformers up to 
their maximum ratings and they are nowhere near being too hot to touch.

The perception of too hot will also change with person. I recall once finding a 
radiator too hot to touch, but someone else could hold their hand on it 
continuously.

Dave