I'm wiring a remote ON/OFF switch for a large room (window mount) air conditioner which is otherwise accessible only via a 8 foot step ladder. Historically, everyone has been going to the fuse panel to do this. I need to use a low-voltage 24VAC control circuit to keep everyone happy (don't bother to ask me why). The A/C is on a 240 VAC,20 amp circuit. . The 240 VAC to 24 VAC transformer I have is a White-Rogers (Steveco) 90-T40M2 and it will be controlling a Supco DP30242 (W-R 90-244) contactor. The same fellow who insists on having the 24 VAC control circuit, also wants the transformer's 240 VAC input to be fused. . As the transformer's output is 40 volt-amps (I know, almost but not the same as Watts), my simple math tells me that if the transformer was 100% efficient, it should only draw a max of 167 mA. In looking at fuses, I see that Bussman makes all sorts of 5mm x 20mm fuses under 1 amp. I'm considering using 300 mA fast acting fuses as that's what's readily available from my local Grainger store. . Am I on the right track here ? I just hope my 'friend' doesn't insist that the 24 VAC wiring also be fused. Or should it, just to be absolutely safe ? The transformer will be installed in a tight location where there will not really be any air flow to draw off heat. And it will likely be energized (even with the A/C OFF) all the time, all year long.
17 years ago