Breaker Size

The data you should use is that appertaining to the wiring. You do realise it is the wiring that the breaker is thereto protect, don't you?

your breaker really only has one job...to protect your wire from carrying too much current to the point it heats up and burns. size the wire right and you'll be fine

according to your post, I don't need breaker if I have a proper gauge wire. I might need breaker for inrush current which will cause to heat up the wires, correct?

You would size the wiring and breaker at the maximum amperage draw + 25% or the closest fuse size available over the max draw, and the wire sized accordingly...You always want the fuse over the max amp draw, and you always want the wire size above the fuse rating by a comfortable margin....

• Rated Current: 1.3 - 7.9 Amp (12 Volt DC) / 0.6 - 4.0 Amp (24 Volt DC)

http://www.defender.com/product.jsp?path=-1%7C2276179%7C2061078%7C2061089&id=1291962

thanks for answer. Is the rated current 7.9 amp consider as a max amperage. 25% addition to max amperage draw, is that percentages implemented to all dc equipment. Can I use this percentages for other AC equipment.

Regarding the fuse size would be over max amp draw by how much percentages.

7.9 amps 12v would be the max....a 15 amp circuit would probably work well....then you need to determine the length of the wire, if it's under 10 ft, a #10 copper wire size would work fine....always check the amp draw on the circuit with an ammeter after completion....I like to use a little conductive grease on wiring connections to keep corrosion at bay....

http://www.solar-electric.com/wire-loss-tables.html

thanks for your answers and for your help

You posted "....always check the amp draw on the circuit with an ammeter after completion...."

What reason needs to check by ammeter, to check continues current or max current?

You check the amp draw to determine if the unit is working to spec....this is basic for any new electrical installation...

May I ask you, regarding same link that is in your answer, what purpose of providing output BTU, and Fuel Consumption. Is that something to do in designing wiring circuitry for the heater.

No, that's how much heat it puts out and how much fuel it takes to do that....

Can I connect two or three equipment to one breaker only to protect those three equipment. Please correct me if I am wrong, in order sharing equipment to one breaker, I need to add up the max load of each equipment,

the total of max load of three equipment x 25% = the size of breaker

equipment could be Navigation system, VHF system, or lights

You seem to know enough to be a Darwin Awards Candidate! And, I'll be happy to nominate you for it

Did you read the instructions that came with it, Mildred? That's where I'd look, then, I'm funny that way.

Did we arrive in the same clown car this morning? Because I'm funny in that exact same way too.

"When in doubt, Read The Funny Manual. (RTFM)" Why don't they teach kids this in school? It would save a ton of problems later on in life.

you don't have to read all the posts. I am new for this things and I want to make sure I am doing the proper thing.

Then do the proper thing and hire a qualified electrician before you do some proper damage that you'll regret later.

What does a diesel heater do?

Are you saying its a generator powering a electrical heating element?

If this is not a off the shelf construct I strongly advise to get an electrician to look at your installation. Otherwise there should be a breaker already so why not RTFM?

for provide air to boat's cabins. It is economical on fuel and power. Not most manuals for equipment provide the fuse size and breaker size, so I have to make calculations and choose also a proper wire size.

Thats where the electrician will help you.

How are you grounding your system? Just asking. On a boot it does not seem to be trivial.

I will share grounding of heater with other dc equipment, just like automotive, how electrical system is grounded.

<...What does a diesel heater do?...>

One of the possibilities is that it heats diesel.

Ha, I did not think of that!

Now I hear it supplies air to cabins. I am unsure how to proceed. I have the feeling the air will smell like diesel . . .

No it does not smell like diesel. In fact, some countries, not in US still use diesel heater. People had no complain about the smell of the heater.

Did you hire an electrician?

In case of a fire with a diesel heater on board there will not be a lot of options to run. You better get this right.

No I did not hire an electrician.

There will be no fire because I used a proper breaker size and wire size.

We'll never really know what happens to this guy, being an Anon Poster. From what this AP has expressed about his electrical knowledge, all we can do is hope this wasn't his fishing boat !

RTFM On page 22 of the installation instructions, there's a square box (figure 26) that says, F= 20 amp (12volt) or F= 15 amp (24volt) So, depending on which voltage your going to use, select the proper wire size for that fuse. Real simple if you RTFM

Thanks for your indication, but I need those type of information for other equipment. I have to know the right fuse and breaker when manual does not mention it.

The installation/ operation manual does tell you the size of fuse to use on page 22.

In your original post/ question you stated " Rated voltage (V) 15 - 95 (130*), that's the output wattage and not the voltage. Also, I didn't not see anything about using a circuit breaker in place of the on-line fuse. The instructions also said to use the supplied "weather's proof fuse holder".

For your own safety and others, you should follow the instructions to the letter. A fire on board while under way is not good for anybody. If you feel compelled to modify the manufacturer's wiring, then you should get an approval from the manufacture, otherwise the warranty is void and if somebody is hurt or killed as a result of the heater, your the one liable for damages.

I followed manufacture requirements for fusing size. The fuse was to protect the electrical device, but beside the fuse, I have a breaker to protect the wires. Is just like in your home, there is a breaker panel separate installed somewhere, in addition there is an internal fuse to protect electrical device.

You really need to stop playing around and get some professional help for your heater and yourself.!

Hire a qualified Electrician to install it. Then, calculation would be unnecessary.