UPDATE: When I asked ABB this question, (they supply the multi-tap transformers we use), their reply was to fuse the 120V and 24V IAW UL and NEC guidelines as seperate supplies not parallel. The winding of the secondary will provide the VA to both. i.e. for a 50VA transformer, 50VA will be...
Can anyone give me a good rule of thumb to use when trying to determine proper fuse sizing of a multi-tap transformer. I know that NEC and UL allows for 250% max on the input side of the transformer and if under 9 amps output then the max is 167% and if 9 amps and over then it is 125%. However...
