Inexpensive DC breaker for small inverter

Steve961

I am putting together a small system for a remote cabin, and will be using the Morningstar 300 watt inverter, with a 200 AH AGM battery, for lights, laptop, etc. I am wondering if there are any inexpensive DC breakers out there for small inverters such as this. I know I could go with a fuse, but I would like to have the convenience of a breaker to disconnect the inverter from the battery when I leave. Morningstar does recommend a 100 amp fuse, but that seems a bit much for a 300 (600 peak) watt inverter.

I was looking at the following from NAWS:

Square D QOU 60 amp DC circuit breaker

Midnite Solar Baby Box Enclosure for 1-4 Din Rail Breakers

Any other ideas or recommendations?

Thanks.

Steve

icarus

Re: Inexpensive DC breaker for small inverter

The Square D QO series are rated for DC, and they are cheap, and they are reliable and they are available nearly every where.

If it were me, ( and I have the same inverter), I would use a 50-100 amp automotive type fuse at the battery to protect the wire. I would then run that into a 30 amp breaker to feed the inverter. I have separate 12vdc and 120vac breaker panels, as some of the loads in the house are 12vdc and some are 120. That way a small QO breaker box can carry all the 120 vac branch circuits as well.

Good luck,

Tony

Solar Guppy

Re: Inexpensive DC breaker for small inverter

For the Morningstar unit, which has a surge rating of 600 watts for 15 minutes I would suggest a 60 amp breaker, MorningStar I believe lists 100 amp in there documentation on the SureSine

Cariboocoot

Re: Inexpensive DC breaker for small inverter

icarus wrote: »

The Square D QO series are rated for DC, and they are cheap, and they are reliable and they are available nearly every where.

If it were me, ( and I have the same inverter), I would use a 50-100 amp automotive type fuse at the battery to protect the wire. I would then run that into a 30 amp breaker to feed the inverter. I have separate 12vdc and 120vac breaker panels, as some of the loads in the house are 12vdc and some are 120. That way a small QO breaker box can carry all the 120 vac branch circuits as well.

Good luck,

Tony

Tony, I don't think that's what you meant. I thought 120 VAC and 12 VDC in the same box was a no-no?

Steve961

Re: Inexpensive DC breaker for small inverter

Tony:

If I went with an automotive type fuse, could I go with a combination like this:

DC blade ATM Maxi-fuse

Inline Maxi fuse holder with crimp terminals


Also, would it be best to have the fuse right at the battery, or 1-2 feet away in the metal box with the 30 amp breaker.

Thanks.

Steve

boB

Re: Inexpensive DC breaker for small inverter

Cariboocoot wrote: »

Tony, I don't think that's what you meant. I thought 120 VAC and 12 VDC in the same box was a no-no?

Not nessecelary. Look at the inverter boxes like MidNite, OutBack and Xantrex etc.
They have both in one. Have for many years. Just gotta make sure they don't touch and have high enough rated insulation, etc.

boB

crewzer

Re: Inexpensive DC breaker for small inverter

Morningstar does recommend a 100 amp fuse, but that seems a bit much for a 300 (600 peak) watt inverter.

The external 100A fuse is a "catastrophe" fuse. The SureSine 300 has three 40A automotive type fuses inside the unit. Check page 13 of the Installation and Operation Manual.

HTH,
Jim / crewzer

icarus

Re: Inexpensive DC breaker for small inverter

Not to argue with a know genius (aka BoB) Marc, you are correct, you caught me in another overworked evening! I have TWO Square D boxes, one 12vdc only and one 120 vac only!

As for your question Steve, the link to the fuse and holder is exactly what I mean. Should be able to source locally, but NWAS is always a good source as well.

Tony

Dapdan

Re: Inexpensive DC breaker for small inverter

Hey Steve,

I use these breakers/disconnects and have had no problems with it over the past year. It is very robust built to operate in very caustic environments (on a boat) and are ignition proof and accept large end terminals. You can get them from any store that caters for boats and they are usually between $30 - $50. Surface mount them and you are ready to go within minutes. They come in a range of amperages of 25 - 150amps and are rated up to 48v.

Cheers...
Damani


http://bluesea.com/category/3/10/productline/overview/174

DeltaFox

Re: Inexpensive DC breaker for small inverter

I found this circuit breaker that will hold 10,20,30,or 60 Amp fuses DC
On Ebay Item # 370213540348.

You might check your auto radio installer. They might have one But it might not be the right size of fuse but you can find it on ebay or the internet.

BB.

Re: Inexpensive DC breaker for small inverter

This link to the seller's ebay listings for circuit breakers may last longer than the auction number.

Interesting looking devices--no rating information (don't really know if it is safe for use on a home sized battery bank or not).

-Bill

Steve961

Re: Inexpensive DC breaker for small inverter

These are some great ideas guys, it looks like I have a lot more options than I thought.

Thanks.

Steve

DeltaFox

Re: Inexpensive DC breaker for small inverter

BB I have one of these coming and between my batterys and the inverter I have a fuse holder , I'll try to put a picture here of it and It seems to be very good.

. Available in 20, 30, 40, 60 AMP - please indicate the one you need in payment.

4/8 awg input &output

Size: 98mm (L) x 43mm (W) x 35mm (H)

High Current Circuit Breaker
Stops Power Surges from Damaging Your Amps

Mount on Panel or Firewall

Unique Push Button Reset can also be used as a Kill Switch

High Tech water resistant housing


This is a photobucket where I have the one that I'm useing right now.
I'm not connecting anything to the house. I have no plans of doing this sence I have made two solar panels now.

Windsun

Re: Inexpensive DC breaker for small inverter

Those look like the standard Euro type automotive 12 volt breakers, but no ratings so I am sure not UL, and no idea if they are good for 24 volts or higher.

Steve961

Re: Inexpensive DC breaker for small inverter

I did a little searching, and found a great little fuse block from Blue Sea that takes MAXI fuses from 30 to 80 Amps. It also accepts wire sizes from 18-4 AWG. I think this is what I will be using.

Blue Sea MAXI Fuse Block

JESSICA

Re: Inexpensive DC breaker for small inverter

Dapdan wrote: »

Hey Steve,

I use these breakers/disconnects and have had no problems with it over the past year. It is very robust built to operate in very caustic environments (on a boat) and are ignition proof and accept large end terminals. You can get them from any store that caters for boats and they are usually between $30 - $50. Surface mount them and you are ready to go within minutes. They come in a range of amperages of 25 - 150amps and are rated up to 48v.

Cheers...
Damani


http://bluesea.com/category/3/10/productline/overview/174

Greetings:

At this site you can find the blue-seas type dc breakers, and some others, for a lot less money:

https://www.surpluscenter.com/sort.asp?numrec=20&lastrec=20&sort=1&keyword=EMWB&catname=electric&UID=2009100407310287