Low gauge cable for small inverter?

[SSHandyman]

Will 0 gauge cables work properly for a 500 Watt PURE SINE inverter? I don't want to have to rewire for a 3000W inverter in the future.

I should mention that I will be hard wiring it to the car battery and the inverter will be in the cargo area of my Sprinter van.

Thanks.

 

[highdesertranger]

to me 0 gauge is way of an overkill for the 500 watt. will it even fit the inverter? for the 3000 watt how long is the run to the battery? might be to small. just FYI Mercedes makes a house batty set up for the sprinter. however the battery sits on the driver side inner fender, so it's still quite a ways to the cargo area. highdesertranger

 

[SSHandyman]

to me 0 gauge is way of an overkill for the 500 watt.  will it even fit the inverter?  for the 3000 watt how long is the run to the battery?  might be to small.  just FYI Mercedes makes a house batty set up for the sprinter.  however the battery sits on the driver side inner fender,  so it's still quite a ways to the cargo area.  highdesertranger

Yeah, looking at the small inverter and 0 cable size, I suspect it may not even fit. 
Run to the battery would be about 6 feet to front of cargo area. The future 3000W inverter might be place at the rear axle.

 

[John61CT]

Learn how to judge for yourself.

Start with Circuit Wizard app from Blue Sea, google the terminology, then

ask clarifying Q's here

 

[Weight]

I'm forced to agree with John. here; http://circuitwizard.bluesea.com/#

DC amperes do not have "too large a cable", only "too small a cable".

My 2000 watt inverter requires a 2/0 cable if less than 10 feet from battery.
I used 2/0 for 30 inches. Inverters do not like lowered voltage.

 

[SSHandyman]

Learn how to judge for yourself.

Start with Circuit Wizard app from Blue Sea, google the terminology, then

ask clarifying Q's here

Thanks so much.  :dodgy:

 

[John61CT]

Really? Just want a bit of fish eh?

OK, get a piece of string and measure as precisely as possible the actual distance.

 

[Seminole Wind]

if you are making a long wire run for a high demand item like the inverter and you want to use wire size larger than will fit. you can run the large wire right up to the item and then just step it down with a bus bar and ring terminals. use the largest wire that fits the inverter for a few inches from the inverter for a few inches to a bus bar and then use what ever wire size you want from the bus bar to the main fuse at/near the battery

that is about the best you can hope for

 

[Weight]

If you do run large cable to a bus bar, then a smaller cable to the inverter, You must fuse for the smaller size wire. But, better is a fuse at battery on cable to bus bar. Then fuse on bus bar for cable to inverter. The Rule. fuses protect wires, not devices.

 

[John61CT]

The smaller size end bit and CP should be big enough for the thermal safety issue.

The long fat run is just for reducing voltage drop.

 

[SSHandyman]

if you are making a long wire run for a high demand item like the inverter and you want to use wire size larger than will fit. you can run the large wire right up to the item and then just step it down with a bus bar and ring terminals. use the largest wire that fits the inverter for a few inches from the inverter for a few inches to a bus bar and then use what ever wire size you want from the bus bar to the main fuse at/near the battery

that is about the best you can hope for

Sounds like a plan. Much thanks.

 

[SSHandyman]

An easy way to reduce the wire size would be to use a split bolt (kearney) and tape especially since it sounds temporary. Available at electrical supply house or might be at big box stores too. Be sure to have the large gauge cable long enough to reach where the 3,000w inverter will be installed. See link for more.
https://www.google.com/search?clien...jcAhVHEawKHdcmAeEQ1QIIigIoAA&biw=1366&bih=654

Guy

I'll check it out. Thanks!

 

[SSHandyman]

if you are making a long wire run for a high demand item like the inverter and you want to use wire size larger than will fit. you can run the large wire right up to the item and then just step it down with a bus bar and ring terminals. use the largest wire that fits the inverter for a few inches from the inverter for a few inches to a bus bar and then use what ever wire size you want from the bus bar to the main fuse at/near the battery

that is about the best you can hope for

Thanks!

I think i thanked you twice. lol No delete button on this site?

 

[SSHandyman]

I purchased a 600W pure sine inverter and will hard wire it to the car battery using the appropriate gauge wires. The round trip length of wires will be about 18 ft. I looked up a conversion chart that gave me these numbers but I don't understand how they arrived at them.  600 watts divided by 12 volts = 50 amps....not 80. ???

[font=ptsansregular, arial, serif]Inverter Voltage  = 12 Volts
Continuous Watts = 600
Max. Inverter Input Amps (DC) = 80
Fuse Size  = 80
(DC Amps) = 80
Circuit Breaker = 80
(DC Amps)
Wire Size (AWG) = 2[/font]

Also, do I calculate using watts from the continuous power watts or the surge power watts?


Thanks.

 

[John61CT]

Watts output AC is lower than DC watts input.

Assume maximum continuous, only bother checking transients if many times continuous, like a Magnum.

 

[SSHandyman]

Watts output AC is lower than DC watts input.

Assume maximum continuous, only bother checking transients if many times continuous, like a Magnum.

How did they get 80?

 

[Trebor English]

I purchased a 600W pure sine inverter and will hard wire it to the car battery using the appropriate gauge wires.  The round trip length of wires will be about 18 ft. I looked up a conversion chart that gave me these numbers but I don't understand how they arrived at them.  600 watts divided by 12 volts = 50 amps....not 80.   ???

[font=ptsansregular, arial, serif]Inverter Voltage  = 12 Volts
Continuous Watts = 600
Max. Inverter Input Amps (DC) = 80
Fuse Size  = 80
(DC Amps) = 80
Circuit Breaker = 80
(DC Amps)
Wire Size (AWG) = 2[/font]

Also, do I calculate using watts from the continuous power watts or the surge power watts?


Thanks.

If the inverter has a loss of 20% then 600*1.2=720 watts input.  720÷12=60 amps.  

Inverters use power in pulses.  They have large capacitors connected to their input to supply the pulses of power.  When you first connect an inverter there is usually a spark as a very high current charges the capacitors.  The 80 amp fuses may be to accomodate that surge.  

It is reasonable to have an inverter bigger than the intended use.  How do you intend to use the inverter?  Do you have a lap top with a 190 watt power supply?  

I have a 400 watt inverter powering a 70 watt fridge, 6 amps.  The compressor starting surge is 70 amps.  I don't have it wired like it is 70 amps continuous.  For a continuous 70 watt 6 amp load I have AWG # 6 wire 9 feet to the battery.

 

[highdesertranger]

first off no conversion is 100% your math is not taking the loss into account. also that 600 watts is the continuous rating, what is the surge rating? highdesertranger

 

[WILD@HEART]

Learn how to judge for yourself.

Start with Circuit Wizard app from Blue Sea, google the terminology, then

ask clarifying Q's here

2 thumb's up! Gain knowledge & skills ... do more & with confidence 

 

[Weight]

""An easy way to reduce the wire size would be to use a split bolt (kearney) and tape""
Easy yes. Temporary yes. Not very good for heavy DC amperes.