As Hammond wrote:
Note about Inrush Current:
Due to the superior magnetic properties of Toroidal transformers they will be susceptible to high magnetizing current when initially energized, only limited by the low DC resistance of the primary winding. Depending on where you are in the AC cycle when the transformer is energized dictates the chances of overloading the supply circuit. This is why the transformer may sometimes energize without a problem and other times it will blow the fuse or trip the circuit breaker. The duration of this overload is rarely longer than a half of a cycle. Therefore, you should consider using a slow-blow fuse, time delayed circuit breaker or other form of soft start circuitry for the supply line when using these high efficient Toroidal transformers.
p.s.
like this
https://www.hypex.nl/product/softstart-module/38
cheaper one:
https://shopdelta.eu/soft-start-module-sf-1_l2_p7242.html
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Thanks!
As the 300VA is at the “crossover” point of toroidal transformers requiring a soft start, I was wondering if it was necessary? Putting a 10A fuse in to cover for the inrush doesn’t leave much in the way of actual protection for the circuit… plus, I guess the inrush stresses the caps…
As the 300VA is at the “crossover” point of toroidal transformers requiring a soft start, I was wondering if it was necessary? Putting a 10A fuse in to cover for the inrush doesn’t leave much in the way of actual protection for the circuit… plus, I guess the inrush stresses the caps…