Two-pole branch protection

[witzgall]

On our boat, the ac circuits are protected with two-pole breakers. For each circuit, the grounds are led to a common ground , with the hot and neutral each disrupted when the breaker is tripped. The neutral is wired back to the main ac two-pole breaker as well as the hot.

All of the outlets are let to a single breaker. Since we are wintering on the boat, this will not power two heaters, as we would like. So my plan is to add an additional breaker to split up the fore and aft outlets. There is not room on the panel for another double pole breaker. I believe it would be ok to put a new, single pole breaker on the hot wire, the ground to the common ground bus bar, and the neutral to the neutral of the main ac breaker. Am I correct?

A whole new panel might be in the future, but we have other things we would like to spend the ###, and the current one seems to be in good order.

The Panel:

Closeup of the AC side. The double pole breaker that has green wires leading to it is the AC Main:

and the rest of the spaghetti:

[Colin A]

Usually you only see the neutral broken on branch circuits on aluminum or steel hulls. In general yes you only need the hot broken on a 120V circuit. ABYC states that the only requirement for breaking a branch circuit with a single pole in the hot is that the AC system must be equipped with a reverse polarity indicator or transformer.

[georgec]

I was about to ask the same question. I presently have a Beneteau. They breaker both the neutral and hot except for the air conditioning panel, where only the hot is through a breaker. My previous 2 boats were Catalina's where only the hots went through the breakers. I am also looking to split up a double breaker into 2 separate circuits breaking only the hots.

[Viking Sailor]

Usually, when an AC panel has a single breaker it is sized to support the maximum power the shore side plug/wiring is capable of handling. So, if shore power is setup for a 30A connection you should have a 30A panel breaker installed. If the panel breaker is less then what the shore plug/wiring is designed to handle -- then replace the current breaker with a correctly sized breaker.

[smac999]

Originally Posted by Viking Sailor

Usually, when an AC panel has a single breaker it is sized to support the maximum power the shore side plug/wiring is capable of handling. So, if shore power is setup for a 30A connection you should have a 30A panel breaker installed. If the panel breaker is less then what the shore plug/wiring is designed to handle -- then replace the current breaker with a correctly sized breaker.

this has nothing to do with the question...


as posted already. the single is fine. most boats are single with a dual master. by abyc you should have a rev. poliarty light if only single breakers. (I would have one either way though..)


it also looks like your main is a triple pole and breaking the ground. this should be bypassed. you don't want the green to disconnect. it should bypass the breaker and always be connected. it's fine it just leave the 3re pole empty once you move the green wire.

[FlyingCloud1937]

Originally Posted by smac999

this has nothing to do with the question...


as posted already. the single is fine. most boats are single with a dual master. by abyc you should have a rev. poliarty light if only single breakers. (I would have one either way though..)


it also looks like your main is a triple pole and breaking the ground. this should be bypassed. you don't want the green to disconnect. it should bypass the breaker and always be connected. it's fine it just leave the 3re pole empty once you move the green wire.

smac,

That's a Paneltronic's panel, and the main is not actually a 3 pole breaker, breaking the earth by design. It's design is part of the reverse polarity circuit. If the shore side is wired reverse polarity, then the ships main will trip automatically. The third pole is a trip coil for the reverse polarity trip circuit.

Now if some hack has been aboard and re-wired it improperly...all design functions go out the window.

Lloyd

[smac999]

Originally Posted by FlyingCloud1937

smac,

That's a Paneltronic's panel, and the main is not actually a 3 pole breaker, breaking the earth by design. It's design is part of the reverse polarity circuit. If the shore side is wired reverse polarity, then the ships main will trip automatically. The third pole is a trip coil for the reverse polarity trip circuit.

Now if some hack has been aboard and re-wired it improperly...all design functions go out the window.

Lloyd

how does that work? where would those green wires normally go to? there would have to be some other device in that system. looks awfully like 10awg main feed wires in and out to me but hard to tell without following them.

[FlyingCloud1937]

Originally Posted by smac999

how does that work? where would those green wires normally go to? there would have to be some other device in that system. looks awfully like 10awg main feed wires in and out to me but hard to tell without following them.

Smac

Paneltronics Main

Recognize that the third pole/earth is not a breaker it's a trip coil. It will pass even when the hot/neutral is tripped.

Again remember I said as long as no hacks have been aboard.

Lloyd

[goboatingnow]

Originally Posted by FlyingCloud1937

Smac

Paneltronics Main

Recognize that the third pole/earth is not a breaker it's a trip coil. It will pass even when the hot/neutral is tripped.

Again remember I said as long as no hacks have been aboard.

Lloyd

What's the device connected across the terminals , a MOV. If so not a great idea.

Dave

[Colin A]

Yeah it's a MOV. This was a pretty common design for main power breakers on panels until recently to provide auto disconnect on reverse polarity. I have heard these can cause nuisance tripping with ELCI's thou.

[goboatingnow]

Originally Posted by Colin A

Yeah it's a MOV. This was a pretty common design for main power breakers on panels until recently to provide auto disconnect on reverse polarity. I have heard these can cause nuisance tripping with ELCI's thou.

Yeah thats what I meant , also as they are tripped , the lower they tripped voltage, essentially getting worse as they get older.


dave

[witzgall]

How do you know it is a paneltronics panel? This is a 1978 Camper and Nicholsons, an english boat. I would think the stuff would be made over there.

The ground is not broken.

Is there any source of those old-style push to set and reset breakers?

Thanks for all of the replies. Now I Just have to mount the new breaker, and split the wiring run from the outlets with some new wire back to the panel for 1/2 of the outlets.

Chris

[FlyingCloud1937]

Originally Posted by witzgall

How do you know it is a paneltronics panel? This is a 1978 Camper and Nicholsons, an english boat. I would think the stuff would be made over there.

The ground is not broken.

Is there any source of those old-style push to set and reset breakers?

Thanks for all of the replies. Now I Just have to mount the new breaker, and split the wiring run from the outlets with some new wire back to the panel for 1/2 of the outlets.

Chris

Paneltronics Breakers

They are a large OEM panel builder, when your boat was built they were one of the largest.

goboatingnow Quote:
Originally Posted by FlyingCloud1937

Smac

Paneltronics Main

Recognize that the third pole/earth is not a breaker it's a trip coil. It will pass even when the hot/neutral is tripped.

Again remember I said as long as no hacks have been aboard.

Lloyd

What's the device connected across the terminals , a MOV. If so not a great idea.

Dave

There thousands upon thousands of those breakers in service. Every SeaRay, Tolley and countless other large boat manufactures. I have never seen a failure in 30 some years.

Lloyd