Can I Combine Breakers?

[tulsag]

For my Hunter 356 I just bought :
1) Raymarine C120W Chartplotter (comes with 7A inline fuse)
2) Raymarine Radar (needs 10A breaker)
3) Raymarine X-5 autopilot (needs 10A breaker)
4) Sirius weather module (needs 5A breaker)

My poblem is that I only have to spots left on my 12V panel and I would prefer to not go to the expense of adding another panel.

1) Can I combine the weather module with the plotter on one breaker because I always want the weather on when the chartplotter is on (weather box pulls a tiny amp amount)?

2) If not, would it be wise to drop my windlass breaker on the panel since the windall has a 70amp breaker below the nav table? Isn't the panel breaker redundant?

I will be installing this equipment BUT I will probably have an electrician wire all of this up. I just want to tell him what I want done and have the necessary parts ready so I don't get charged as much

Mark

[MJWEENZ]

Not recommended. The breaker is designed to protect the wire. If you put a 15a breaker on 10a wire the amp draw from a short could get the wire hot enough to cause a fire hazzard before the breaker would trip.

[GordMay]

Sure.

Use a 20A Breaker, feeding #12AWG minimum wire size, to a terminal block with &A & 10A Fuses feeding Plotter & Radar.

3) Raymarine X-5 autopilot (needs 10A breaker)
4) Sirius weather module (needs 5A breaker)

Use a 15A Breaker, feeding #14 AWG minimum wire to terminal block with 10A Fuse & 5 A fuse feeding Pilot & Weather.

Gord, Master Electrician

[roverhi]

You can wire all to the same breaker then use inline fuses for the various pieces of equipment. The primary breaker would have to be sized to handle the current of all the pieces of equipment that will be on at one time. If the fuse/c/b capacity for the units are right, that would be a 32 volt primary breaker. You could split it between the two spots you have left and use a smaller breaker.

The breaker for the windlass that is on the panel cannot be a breaker to handle the windlass current. They have a 70 amp breaker elsewhere which does handle the winch current which can get up to 70 amps or more under load. You'd have to trace the wire down to see what this windlass panel breaker does. It could be connected to the controller or winch switch which are much lower voltage. You could do an inline fuse for those circuits, if that's the case, and free up that breaker.

BTW, it's not considered good practice to run muliple wires to the circuit breaker. Run the wires to a junction strip and then a single heavy wire to the breaker.

[sabray]

On the windlass. I would bet that the panel breaker is for the control side and not taking the windlass load. So that circuit needs to be protected as well. seems like you may want to add a sub panel that would provide you with options in the future.

[Pblais]

I will be installing this equipment BUT I will probably have an electrician wire all of this up. I just want to tell him what I want done and have the necessary parts ready so I don't get charged as much.

The general rule is when you hire an electrician they help you figure the best way to wire this up. Both of the approaches you are leaning toward are only based on reduction of costs and totally compromises safety. I wouldn't hire any electrician that would agree to do either of your suggested approaches. Doing it yourself would get you in a similar amount of trouble.

You could add a sub panel or in line fuse multiple items on one circuit but it's not always the best way to do things. Even at that there are better and worse ways to do even that. Work with the electrician and design a proper layout. It's that advice that makes it worth hiring them.

80% of all boat fires come from an electrical source. DC current is not like household AC current. If you screw up, the wires get hot just like a toaster oven. You'll burn to the water line after the Dock master cuts your dock lines to save the rest of the marina.

Plan the electrical work before you do any work yourself or buy any materials. You can't get by with hardware store electrical supplies on the cheap. The proper wire and connectors matter as much as the layout.

[MJWEENZ]

Gord's way is the best of the two, but if you are going to the trouble of of a terminal block with fuses why not install the subpanel?

1) Much easier to find a tripped breaker then a blown fuse
2) If you are that short of space in your panel how long will it be before you will broach this subject again?

Do it right the first time, allways cheaper in the long run.

[GordMay]

Any competent electrician will know how to safely & efficiently feed several devices from a single breaker (through a splitter & fuses, or a sub-panel, as I previously posted).

The 70A Windlass Breaker in the Panel may be redundant, if it feeds a separate 70A breaker (which then feeds the windlass) nearby. It won’t be cost effective to re-use the 70A panel breaker to feed the new instruments, as that would require #8 or #6 AWG Wire (Columns 1 and 4 or 5 below).

Wire Sizing & Voltage Drop Table:

See ➥ http://www.cruisersforum.com/gallery...r&imageuser=79

And ➥ http://www.cruisersforum.com/gallery...r&imageuser=79

Everyone who contemplates any electrical work should print and save these 2 pages.

[tulsag]

Now I'm wondering if the panel breaker is just a relay to the up/down controls on the bow. It is only a 5 amp breaker.

[goboatingnow]

in my opinion in-line fuses have no place on a boat. I remove all mine before installation. All circuits should be protected by resettable breakers. Fuses exist to protect the cabling, which breakers do a better job off. Otherwise the elctronics will do a nice job of protecting the fuse anyway

[roverhi]

It's fine to have a breaker on the panel for each appliance but not possible in real life. Most electronics require fuses of from 1 to 5 amps. That's the manufacturers specs. You'd end up using up a bunch of C/B spots on your electric panel and be in danger of tripping the circuit breaker constantly if you run more than one device rated at the C/B capacity off the same circuit. It would be nice to have a breaker for everything but you'd have a Panel the size of many people's boats.

Aloha
Peter Ogilvie
Pa'akai O'o, Pearson 35 #108
Too many Landrovers, some even run.

[Tellie]

I think Pauls first impression as was mine is that the OP was refering to "double tagging" landing two or more wires on the same breaker. If that was the case Paul is absolutely correct.

[Ex-Calif]

What else is on the panel? Can anything else be combined - i.e. cabin lights and cabin (9V) outlets?

I combined these circuits and my small 300W inverter. The inverter sits on a shelf and is accessible so I left the inline fuse on this unit even though it is probably redundant.

I agree in general about no in-line fuses. If you must use them make sure they are accessible.

[GordMay]

Originally Posted by tulsag

Now I'm wondering if the panel breaker is just a relay to the up/down controls on the bow. It is only a 5 amp breaker.

You’re right. The 5A Breaker supplies the relay coil, and the 70A breaker the motor power. Both are required, in your application.

Originally Posted by goboatingnow

in my opinion in-line fuses have no place on a boat. I remove all mine before installation. All circuits should be protected by resettable breakers. Fuses exist to protect the cabling, which breakers do a better job off. Otherwise the elctronics will do a nice job of protecting the fuse anyway

Not quite right.
For good reason, manufacturers often provide power supply fuses (external, or damnably internal) to protect delicate internal wiring & devices.

[CharlieJ]

Combine all of the good ideas by feeding a Blue Sea Systems 6 circuit AT0/ATC fuse panel; p/n 5025. Feed it with AWG 10 wire from a single 20 amp circuit breaker. Wire the ground bus from the 5025 to the Vessel Ground. Label the circuit breaker "Electronics" and you are good to go with a clean and professional install.