Small AC motors and Inverters
Disappointed that my ancient Mod Sine Wave inverter (140W cont, 200W surge) shuts down with a 120W coffee grinder. Works ok with the 400W (cont) MSW inverter built-into the truck, though a little ...
Forum Discussion
MrWizard wrote:
Never wire anything for a planned maximum use like 5 min
always use wire sized as continuous power use/load
...
Ahh, ok. That makes sense.
I was assuming the inverter's claimed ability to go 1100W for 5 minutes was the worst case. But it's not.
So if instead I use the inverter's 1000W continuous rating, or 83.3A at 12V, and plug that into the Blue Sea Wizard with a duration of 10 min or above, I get 4ga with a de-rating to 136A. It is Ampacity that determines the 4ga, not the 3% limit on voltage drop at 8ft.
And it is somewhere around 8-9 min duration that the recommendation changes from 6ga to 4ga. Suppose I could then stick to 6ga as it doesn't take that long to grind coffee, but think it would be better to accommodate the inverter's true potential. Who knows what we'll end up doing if I ever get the thing installed.
OK. So 8-10ft of 4ga de-rated to 136A. So that means I should protect this cable with a 136A fuse or below? Have I got that part, at least, correct?
And I apologize for any ruffled feathers. I do like to learn and understand what I'm doing. (and was never good at blindly following orders).
