Post by kit on Oct 4, 2016 17:07:04 GMT
Have a small backup system in the making, nearly complete.
150w panel with 30a controller, 12v bat (2 6v golf cart), and 1000w (2100w peak) MSW "half-voltage" inverter (AC 60v each on the black and white sockets, no real ground on the ground socket, pretty common for smaller MSW inverters, from what I've read).
I would use this for some modest backup during outages and to power some portable lights/equipment at times, just to make use of the sun.
I'm fine with the setup on the DC side and have probably more than enough protection there w regard to fuses/breakers.
My questions have to do with the AC side.
One article I read indicated that for smaller inverters, say up to 1000w models like mine, no overcurrent protection would be necessary on the AC side if you're using a reasonable gauge of extension cord, because the smaller inverters just aren't able to ever produce enough juice on the AC side to burn the wires (I ASSUME this means even in a short circuit situation, but not sure). Besides, my inverter, like all or most of them, has some built-in protections for "short circuit, overload, over temperature, low battery voltage, over battery voltage" and according to reviews it DOES automatically switch off in cases of too much load. The manual says nothing about fuse/breaker protection being needed on AC side.
So would I really need any sort of protection at all for overcurrent or short if I want to avoid any fire danger? What would be worse-case scenario if there was a short on the AC side, and if the inverter didn't shut off as promised? Is there any chance at all of the extension cord becoming a fire hazard with this size of inverter, or would the inverter just get smoked before that could ever happen? Or would the 100a fuse on the DC side blow instead?
Also, if I use this to power a machine that is separately grounded to the main (like a power-corded gas furnace during a power outage--no backfeeding of course!) would that present any special problem if there was a short to ground? If overcurrent protection is at all desirable, are there some inline options for fuses or breakers that would be ideally be pluggable into the extension cord or fittable into a diy inline box?
Thanks.
150w panel with 30a controller, 12v bat (2 6v golf cart), and 1000w (2100w peak) MSW "half-voltage" inverter (AC 60v each on the black and white sockets, no real ground on the ground socket, pretty common for smaller MSW inverters, from what I've read).
I would use this for some modest backup during outages and to power some portable lights/equipment at times, just to make use of the sun.
I'm fine with the setup on the DC side and have probably more than enough protection there w regard to fuses/breakers.
My questions have to do with the AC side.
One article I read indicated that for smaller inverters, say up to 1000w models like mine, no overcurrent protection would be necessary on the AC side if you're using a reasonable gauge of extension cord, because the smaller inverters just aren't able to ever produce enough juice on the AC side to burn the wires (I ASSUME this means even in a short circuit situation, but not sure). Besides, my inverter, like all or most of them, has some built-in protections for "short circuit, overload, over temperature, low battery voltage, over battery voltage" and according to reviews it DOES automatically switch off in cases of too much load. The manual says nothing about fuse/breaker protection being needed on AC side.
So would I really need any sort of protection at all for overcurrent or short if I want to avoid any fire danger? What would be worse-case scenario if there was a short on the AC side, and if the inverter didn't shut off as promised? Is there any chance at all of the extension cord becoming a fire hazard with this size of inverter, or would the inverter just get smoked before that could ever happen? Or would the 100a fuse on the DC side blow instead?
Also, if I use this to power a machine that is separately grounded to the main (like a power-corded gas furnace during a power outage--no backfeeding of course!) would that present any special problem if there was a short to ground? If overcurrent protection is at all desirable, are there some inline options for fuses or breakers that would be ideally be pluggable into the extension cord or fittable into a diy inline box?
Thanks.