Xantrex 1500W Inverter...What size fuse at battery?

[Skillet]

I just installed the above mentioned inverter in the back of my rig. The recommended 5' power cord is actually more like 10' but I could not help that. Hopefully it won't be a big issue.

Question is, what size fuse should I put in the positive feed right by the battery.

I read the literature on the inverter and it says it should be what your battery's short circiut rating is. Somewhere in the neighborhood of 500 Amps?!?

That sounds mighty high doesn't it?

Someone at West Marine said 40 amp. There is a big friggin' difference there.

I am very confused. Any ideas?

 

[firetruck41]

I just installed the above mentioned inverter in the back of my rig. The recommended 5' power cord is actually more like 10' but I could not help that. Hopefully it won't be a big issue.

Question is, what size fuse should I put in the positive feed right by the battery.

I read the literature on the inverter and it says it should be what your battery's short circiut rating is. Somewhere in the neighborhood of 500 Amps?!?

That sounds mighty high doesn't it?

Someone at West Marine said 40 amp. There is a big friggin' difference there.

I am very confused. Any ideas?

What size cable did you use? I think you will have to fuse it based on the cable size, because you won't be able to get all the amps outta' that thing unless the cables are monstrous.

FWIW, I used a 100A megafuse for my 800 (1700peak) inverter, used 4G cable from battery several inches to fuse, then 4G cable for about 6-8 feet to the inverter. My inverter has two 50A in series (?- 100A total)fuses in it. What is the fuse(es) in your inverter?

 

[Skillet]

What size cable did you use? I think you will have to fuse it based on the cable size, because you won't be able to get all the amps outta' that thing unless the cables are monstrous.

FWIW, I used a 100A megafuse for my 450w(800w peak) inverter, used 4G cable from battery several inches to fuse, then 4G cable for about 6-8 feet to the inverter. My inverter has two 50A in series (?- 100A total)fuses in it. What is the fuse(es) in your inverter?

I used some fat-ass cable.

I think it is 2.

I had it left over from my dual battery install, marine grade, tinned, expensive fat cable. If I cannot pull amps through that, I don't know what will work.

The ground is just the 4 that came with the unit, grounded to the frame in the back of the rig.

I will have to wait until later to check the fuses in the unit.

Do you think a 100 amp mega would be good for mine?

I can grab that from west marine at lunch. I think they had a 175 there too.

I was thinking I might get a circuit breaker instead. That way I don't have to worry about carrying extra fuses.

Decisions, decisions...

 

[firetruck41]

I used some fat ass-cable.

I think it is 2.

I had it left over from my dual battery install, marine grade, tinned, expensive fat cable. If I cannot pull amps through that, I don't know what will work.

The ground is just the 4 that came with the unit, grounded to the frame in the back of the rig.

I will have to wait until later to check the fuses in the unit.

Do you think a 100 amp mega would be good for mine?

I can grab that from west marine at lunch. I think they had a 175 there too.

I was thinking I might get a circuit breaker instead. That way I don't have to worry about carrying extra fuses.

Decisions, decisions...

With that high amperage, I decided I just wanted a fuse, because I could only find automatic circuit breakers. If you get a mega fuse holder, you can always change the fuse size pretty easily, but I'll bet a 100A fuse will work fine, it probably won't give you the max power your inverter can use, but might be enough "for now".

I would check the fuses in the unit, check which wire exactly do you have, and then go online and find some wire gauge references and make sure your mega fuse will fail before the wire, and hopefully provide you with the same amperage as the fuses in the unit.

 

[Skillet]

I was thinking about this one...

It is manual reset and looks pretty sturdy.

CIRCUIT BREAKER 150 AMP SFC MT

 

[wussyPup]

I'm not an expert, but, I would start with:
(surge capacity in watts) / (low voltage cutout in VDC) / (efficiency in %) = minimum fuse size (amps)
e.g.
(3000 watts) / (10 VDC) / (90%) = 333 amps minimum fuse rating
And then, make sure that your cable can carry that much current at max expected voltage (15 VDC)

The intent isn't to protect the inverter, it's to protect the battery from overloads (and the truck from shorts) while ensuring that all the current that the inverter may want is available. If the inverter fails or there is a short, then the fuse should self sacrifice to protect the battery and end the overload or short.

G'luck, -Steve

 

[Rich]

The function of the supply fuse is to protect the wiring from overheating and starting a fire. Since your ground is 4 gauge, then your fuse should be at or below the ampacity for 4 gauge wire. Look it up online, you can search out ampacity ratings for various gauge wire. In order to obtain full value of your 2 gauge feed, your ground should also be 2 gauge, in which case you could up the fuse rating accordingly. Note that ampacity is dependent on ambiant temps; ampacity rating for wiring in an engine space will be lower than wiring in a non engine space.

 

[firetruck41]

I edited my post above, my inverter is a 800/1700w unit.

I agree you must fuse based on your smallest wire. Ideally you will use wire which will be able to provide more than the required amperage, to your inverter, and you can fuse it as such.

 

[alia176]

I agree with Rich, both wires should be the same gauge and the pos wire fused accordingly. Use a 12vdc wire chart for wire length/size/temp for selecting fuse size. This is a lot of current and your vehicle's future life depends on how you protect the cable!

On another note, those of you who are using portable hitch mounted winches for the front and rear, what're you doing for the long wire run in term of protection?

Ali

 

[450 DUDE]

The function of the supply fuse is to protect the wiring from overheating and starting a fire. Since your ground is 4 gauge, then your fuse should be at or below the ampacity for 4 gauge wire. Look it up online, you can search out ampacity ratings for various gauge wire. In order to obtain full value of your 2 gauge feed, your ground should also be 2 gauge, in which case you could up the fuse rating accordingly. Note that ampacity is dependent on ambiant temps; ampacity rating for wiring in an engine space will be lower than wiring in a non engine space.

What he said.

Im using that resetable circut breaker ,nice unit



ken

 

[450 DUDE]

On another note, those of you who are using portable hitch mounted winches for the front and rear, what're you doing for the long wire run in term of protection?

Ali[/QUOTE]

On the # 2 wire that I have running to the back Im using silicone coated fiberglass tubing.
I just shoved the whole run inside the tube (not easy I went for close tolreance)


ken

 

[alia176]

I shoudl've said "fuse protection". I ask this because I don't think any of these folks are running any type of fuses/breakers on the winch wires. So, my next thought would be "what about a short circuit condition inside the winch and burning down the vehicle"! I am not running any fused projection for the short run of my #2 winch so I guess I'm in the same boat as well!


Ali[/QUOTE]

On the # 2 wire that I have running to the back Im using silicone coated fiberglass tubing.
I just shoved the whole run inside the tube (not easy I went for close tolreance)


ken[/QUOTE]

 

[firetruck41]

I shoudl've said "fuse protection". I ask this because I don't think any of these folks are running any type of fuses/breakers on the winch wires. So, my next thought would be "what about a short circuit condition inside the winch and burning down the vehicle"! I am not running any fused projection for the short run of my #2 winch so I guess I'm in the same boat as well!


Ali

On the # 2 wire that I have running to the back Im using silicone coated fiberglass tubing.
I just shoved the whole run inside the tube (not easy I went for close tolreance)


ken

I would consider putting one of those manual throw switches near the battery, it wouldn't be automatic, but if something starts smokin' you could throw the switch real quick before burning down the truck. They are pretty high amperage IIRC.

 

[FJ40_owner]

My Xantrex 1800 W recommends the Following

From the owners manual
@ 12 VDC
Marine or RV Install
Wire #1
Fuse 300 Amp.

From me - You do not get something for nothing. Watts are Watts
1800 watts at 120 VAC equals 15 Amps
1800 Watts at 12 VDC equals 150 Amps
150 Amps will melt a 1 gage wire and cause a fire.
Don't forget all the inefficiancies.
And never forget to fuse the DC side

I just installed the above mentioned inverter in the back of my rig. The recommended 5' power cord is actually more like 10' but I could not help that. Hopefully it won't be a big issue.

Question is, what size fuse should I put in the positive feed right by the battery.

I read the literature on the inverter and it says it should be what your battery's short circiut rating is. Somewhere in the neighborhood of 500 Amps?!?

That sounds mighty high doesn't it?

Someone at West Marine said 40 amp. There is a big friggin' difference there.

I am very confused. Any ideas?

 

[nullifier]

I'm running a 150 resetable circuit breaker on my 1000w xantrec invertor. You can see it in the following pic in the bottom right corner. Hard to make out next to the invertor but the 2 red buttons on it are visible.

 

[Dunbar]

Skillet -
I have the same inverter and am planning the install.

Is yours still working fine? Did you change anything?

Mine came with #4 wire 6' long and said going longer requires 2 gauge with a 10' max.

 

[Corbet]

I was thinking about this one...

It is manual reset and looks pretty sturdy.

CIRCUIT BREAKER 150 AMP SFC MT

I'm not going to enter the amp rating debate but have one of these breakers installed between my battery and accessory fuse block. Mine is only a 60A unit but would not hesitate to use one again for another application in the future.