JD5520 750Watt Inverter Hardwire

[Squeak n Itch]

Just out of curiosity, what gauge is the input wire you currently use when hooked up temporarily? If you use this same input wire for your permanent setup, shouldn't that determine the fuse size rather than the calculations?

 

[patrick_g]

Every fuse in the circuit has a voltage loss inherent in its passage of current. Fuses blow by heating. In order to make maximum use of available power use only the protection built into the inverter. Protect the primary wires physically to prevent shorts - or else use hi value fuse ~ double max primary demand. This will avert frying the wires in a short, but have virtually no loss in normal operation in comparison to a smaller fuse.
larry

Care to give an estimate of the voltage drop across a fuse of the size in question required to blow the fuse?

How does that compare to variations in battery voltage of a tractor during normal operations (not including cranking the engine?)

Pat

 

[TC33DRon]

I am adding a unit to my tractor also. Just wanted to say thanks for all the good advise. This site is great!

Ron

 

[SPYDERLK]

Care to give an estimate of the voltage drop across a fuse of the size in question required to blow the fuse?

How does that compare to variations in battery voltage of a tractor during normal operations (not including cranking the engine?)

Pat

It depends on how fast you want to blow it -- 10sec~ 50mV, 4sec~150mV not counting the losses inherent in each conection to the fuse [another couple mV per under load for GOOD connections]. Multiple fuses just add these losses and altho they are small, the inverter will have a fast acting low voltage cutoff somewhere above 10V. Loss of an extra tenth of a volt or three can be real significant when losses under high load in the battery, wiring and fusing add up to limit the inverter supply to near its cutoff. Thats when the fusing turns into a nuisance.
larry

 

[Soundguy]

Minutia...

If your supply battery is already drained so low that when under load it is nearing the 10v cutout, that a few milivolts makes a difference.. you are already whipped.. the battery would have only been good for what? another few seconds of load time? please... upgrading wire sizes and connection types will buy you more leeway than arguing about 2 overload devices in series...

soundguy

It depends on how fast you want to blow it -- 10sec~ 50mV, 4sec~150mV not counting the losses inherent in each conection to the fuse [another couple mV per under load for GOOD connections]. Multiple fuses just add these losses and altho they are small, the inverter will have a fast acting low voltage cutoff somewhere above 10V. Loss of an extra tenth of a volt or three can be real significant when losses under high load in the battery, wiring and fusing add up to limit the inverter supply to near its cutoff. Thats when the fusing turns into a nuisance.
larry

 

[groundcover]

I was wondering why no one mentioned the cordless route, wkpoor is right, I went eithh the V-28 impact and just love it.
Milwaukee Electric Tool - 0779-22, V28™ 1/2 in. Impact Wrench Kit, Cordless Impact Wrenches, Cordless Impact Wrenches, Tools

 

[SPYDERLK]

Minutia...

If your supply battery is already drained so low that when under load it is nearing the 10v cutout, that a few milivolts makes a difference.. you are already whipped.. the battery would have only been good for what? another few seconds of load time? please... upgrading wire sizes and connection types will buy you more leeway than arguing about 2 overload devices in series...

soundguy

OH. Somehow I thot I was talking about a few hundred mV. As for battery drops under load there remains the consideration of battery vs inverter size, and nature of load being run, in order to correctly fold the blanket statements to fit. In a competent well routed installation fuses will cause more inconvenience and trouble than they avert unless the fuses are oversized significantly.
larry

 

[Soundguy]

Ok.. a couple hundred milivolts.. same argument.. .f .2 to .3 v drop kicks yer inverter to shutdown due to low supply.. AGAIN.. yer already whipped.. yer supply battery is underrated or DEAD... .2-.3v is minutia...

soundguy