Dave Plowman (News) wrote:


Is there a 'rule of thumb' for mains fuses for such devices? And this
isn't the first disc ceramic I've come across which has failed short
circuit. Better type?

Hi,

To fuse a transformer winding I would:

1. Check manufacturers current rating on the winding.
2. If unavailable, determine the wire guage and work the amperage
3. To allow for inrush, I would measure it and pick the right curve on
the fuse. If that is impratical, a thermal type resettable protector
might be an idea (integrates the current pulse over time).

You may check http://www.belfuse.com/SignalTransformer/ to see if
recommendations for fusing their products are provided. Even though
your transformer may be different, the considerations and methodology
should be similar.

Regards,
Jim