400w Inverter Show Fault with TV Plugged In...

[SailingHarry]

That's an explanation that makes sense. Now that I'm done testing the inverter to see if it works, I will hard-wire it into the system. Should I put it on its own breakered circuit, or use an inline fuse?

I'm not sure where you will tie it "into the system," but I will point out that this is a 30A+ load. That's a LOT of current, especially for any load near capacity for any length of time (I don't see it as a battery issue -- I know you won't run a 400W load on battery for more than a few moments -- it's more of a circuitry thing). That kind of load needs to have short wires to keep losses to a minimum. I would suggest perhaps tying right off the battery switch.

As far as a breaker or an inline fuse, the first issue is size -- can you get an inline fuse big enough? If you can, the on-off switch on the unit is probably suitable for the control of power, and the fuse is suitable for protection. If you ever need to take the circuit down hard, you can just pull the fuse.

Harry

 

[Bill Roosa]

Yea GorillaToast
kinda like trying to jump start your car with allagator clips. If you get a good solid connection your fine but you generally can't. that is why I was asking about the voltage ON the clips not the battery voltage. The voltage drop across the battery terminal to clip connection could be on the order fo 5 volts (or more) but that will not show up till you try and pass current.
We have similar discussions on the Hunter stater solenoid circuit all the time. If you measure it while unpluged you get battery current due to no current flow, if you measure it while connected and passing current you get something less than 9 volts.

 

[Bill Roosa]

oops
should be .....unpluged you get battery VOLTAGE due to no current......

 

[mitiempo]

That's an explanation that makes sense. Now that I'm done testing the inverter to see if it works, I will hard-wire it into the system. Should I put it on its own breakered circuit, or use an inline fuse?

I would use a fuse, sized over the inverter draw at max output and below the ampacity of the wire you are using to the batteries. Probably a 50 amp fuse near the battery and the shorter the cables are to the battery the better. But you will be plugging direct into the inverter so you will want it conveniently located. Figure the distance (there and back) to determine wire size with minimal loss.

 

[GorillaToast]

I would use a fuse, sized over the inverter draw at max output and below the ampacity of the wire you are using to the batteries. Probably a 50 amp fuse near the battery and the shorter the cables are to the battery the better. But you will be plugging direct into the inverter so you will want it conveniently located. Figure the distance (there and back) to determine wire size with minimal loss.

I already have a 50amp thermal breaker located within 7" of the battery between the battery and the battery switch. + then goes to a terminal strip prior to heading to the breaker panel. If i take the + for the inverter off that terminal strip and the - straight off the battery terminal, should I be ok? Assuming properly sized cable, of course.

 

[scottthardin]

I simply bypassed the 110v to 12v step down brick and wired my little 19" flat screen into the 12v system of the boat. Works great. I don't know of any downsides to this approach but would be interested in other's opinions. I have always found that the cheap 400w inverters perform poorly and somewhat inconsistently when powering anything more than a phone charger.

 

[Bill Roosa]

Taping off the existing fuse will work fine IF
the rest of the loads don't overload the fuse. Kinda have to do a sanity/probability check on the max the fuse will see in all siturations the inverter would be on. If you get an over the limit situation then just develop some "boat rules" that you can't run the inverter and the macerator (for instance) or start the motor at the same time. Then post that near the macerator switch and the ignition switch to remind you.
Alternatly you could just do what the industry does and use a fuse the correct size to protect the wire (that is what the fuse is intended to protect BTW). Then you can add components right up to the wire ampacity and no problem.

 

[GorillaToast]

Macerator? Ignition?

I've got a 5 gal bucket, and a starter rope to pull...

My total loads at any one time could possibly be, nav lights, cabin lights, instruments, stereo, 12v ipad charger. I probably wouldn't, say for instance, use the inverter to run a coffee maker while I was steaming under outboard power at night, with the tv, charger, and cabin lights on. However, I might brew a cup of coffee while at the dock with the tv and cabin lights on, while charging my ipad from the 12v outlet, but I think the 50 amp breaker should handle that. Shouldn't it?

Small boat, simple systems.

Good information tho, to store for the next, more complicated boat.

Thanks Bill.

 

[Bill Roosa]

You don't have a place to take a dump but you have and electric coffee pot????
I'm thinking you should be looking for a new and bigger boat.
I have two places to take a dump and can't even consider running an electric coffee pot. I do have a gas fired one which works great.

 

[GorillaToast]

Don't have an electric coffee maker, yet. Won't need one if I don't get a dock this season, and can't sleep over on the boat. Really don't need one anyway. Last year I just made up coffee at work, and filled a thermos. It was still hot until noon the next day, when I went back to work, and made some more coffee, and filled up the thermos... well you get the idea. Just mentioned a coffee maker as an example of a 110v appliance I might someday have on board.

If I do get a dock, marina bathroom is just a few steps away, and I never get to be out on the lake long enough to need...

I'm just trying to learn to work on boat systems, and cover contingencies in case the need or opportunity should arise to take this boat to the coast to live aboard before I can save up enough for a bluewater boat. Plus, almost everything I'm adding that's way too much for a daysailer, I plan to take with me to the next boat; i.e. solar panel and controller, stereo, inverter, gas grill, etc.

Since I don't expect to get even what I paid for it, considering the market, no matter what improvements I make, I'm trying to add only things I can take with me, leaving the boat mostly the way I got it, except for those repairs that were necessary for seaworthiness.