2400W or 3KVA 24VDC inverter charger wires and breakers?

[runcoach]

Hello all,

I have a 24VDC or 25.6VDC 200AH Lifepo4 battery to connect to this and I am wondering about wire size to connect the battery and an appropriate breaker. 4AWG wire is recommended in the manual and I am wondering about a breaker. Here is a pic of the label on my inverter/charger. I was thinking of using two waterproof DC isolator switches, one for the battery and one for the PV. I am a newbie so be gentle. I am making this a mobile unit for use in my house and camper.

 

[Brucey]

DC isolator switch like an imo style disconnect will work well for the pv disconnect. They are spring loaded so they will open quickly, without potentially having an arcing issue. They are rated for 32A generally. However to disconnect the 110A+ of DC from the battery to inverter you would need something different. A rotary DC rated switch is commonly used for this, deep sea, Victron etc.

https://www.amazon.com/Victron-Energy-VIC-VBS127010010-Battery-Switch44/dp/B095X94JXF

 

[Brucey]

Or something like this which will give you over current protection as well:

MidNite Solar MNEPV125-80-1PNP Circuit Breaker 125A 80VDC

Shop now for MidNite Solar MNEPV125-80-1PNP Circuit Breaker 125A 80VDC.

www.stellavolta.com

 

[740GLE]

What is the connection method for battery DC connections on the unit? M8 lugs?

 

[runcoach]

What is the connection method for battery DC connections on the unit? M8 lugs?

Yes.

 

[runcoach]

Or something like this which will give you over current protection as well:

MidNite Solar MNEPV125-80-1PNP Circuit Breaker 125A 80VDC

Shop now for MidNite Solar MNEPV125-80-1PNP Circuit Breaker 125A 80VDC.

www.stellavolta.com

I read your first reply and then this. You followed my thought process exactly. But, since the manufacturer recommended 4AWG wire, shouldn't I go with a 100 amp or even an 80 amp breaker, or will it just trip all the time?

 

[Brucey]

If you are at the full load of the system looks like it will pull 110A. An 80A or 100A breaker may nuisance trip.

 

[740GLE]

Also you could do 2awg or 1/0 to be well within the safety margin of that breaker if you felt 4awg was too small for a 125a breaker.

Just be aware that’s a huge surface mount breaker, not the easiest to incorporate in a simple DIY build.

A simple 125-150a fuse such as MRBF fuse terminal holder provides similar protection at a fraction of the cost and space

 

[Brucey]

That 125A breaker is only $40, 1/4" terminals, it's not the same size as the gigantic 175/250A panel mounts at $80-100.

Decent brand mrbf terminal plus fuse prob same price range but I'll give you the size far more compact and manageable.

 

[runcoach]

So, should I upgrade the wire to 2AWG so the breaker trips before the wire heats? They recommended 4AWG I thought that is only good to 85 amps.

 

[Brucey]

I would go with 2AWG for peace of mind and safety margin. A lot of it depends on your cable length as well.

 

[runcoach]

Thank you.

 

[runcoach]

Also you could do 2awg or 1/0 to be well within the safety margin of that breaker if you felt 4awg was too small for a 125a breaker.

Just be aware that’s a huge surface mount breaker, not the easiest to incorporate in a simple DIY build.

A simple 125-150a fuse such as MRBF fuse terminal holder provides similar protection at a fraction of the cost and space

Thank you.

 

[740GLE]

That 125A breaker is only $40, 1/4" terminals, it's not the same size as the gigantic 175/250A panel mounts at $80-100.

Decent brand mrbf terminal plus fuse prob same price range but I'll give you the size far more compact and manageable.

Ahh my bad thanks. That is a nice price.