Max Power Consumption vs Max Power Rating

Discussion in 'Homework Help' started by hitmen, Nov 17, 2013.

1. hitmen Thread Starter Active Member

Sep 21, 2008
159
0
AC Power Max Rating
750W​

System Power Consumption

330W nominal/400W max​

Input-Voltage Range and Frequency

AC 100 to 240 VAC 50-60 Hz/DC -72 VDC to -40 VDC​

DC Power Max Rating

750W​

Total Output BTU (Note:

1000 BTU/hr = 293W)

1122 BTU/hr (330 W) nominal/1365 BTU/hr (400 W) max​

Input Current

AC 11A @ 110VAC, 6 A @ 200VAC/DC 25A Max​

Output Ratings

12V @ 62A & 3.3V @ 3A​

Output Holdup Time

AC = 16 ms; DC = 4 ms @ maximum load​

Dear guys, how do I calculate the fuse for this appliance? Do I take the power of 400w or 330w? Why does it differ so much? Which voltage do I take? Sorry noob here.​

Why does a fuse trip based on the amount of current an appliance draw? Why not voltage or power? What happens if I use a fuse that far exceeds the current it is supposed to used? e.g 10A fuse for 1A appliance​

Last edited: Nov 17, 2013
2. WBahn Moderator

Mar 31, 2012
18,087
4,917
It looks like whatever this is can be operated off of several different supply sources and the nameplate is simply generic and covering all the bases.

It's hard to interpret some of the data when you haven't told us what this thing is.

For fusing, I would use the Input Current ratings for whichever power source is being used.

If you use a fuse that is too high then the unit could malfunction and draw lots of excess current without blowing the fuse. Depending on the appliance, that could be a recipe for serious damage to the equipment or a fire or other not-good things happening.

The fuses are based on current because the voltage is going to be pretty stable and unchanging. Since that's the case, fusing on the current and fusing on the power are essentially one-and-the-same.

3. WBahn Moderator

Mar 31, 2012
18,087
4,917
Oops. I just realized that this was in Homework Help.

I don't know if I gave away too much too easy or not. I guess I'll let it stand.