2 neutral breakers in a single load center

[sdowney717]

is there a load center box where you can take in 2 hots on separate phases, breaker the output to 30 amps AND also include a neutral breaker on each hot breaker?
I know square-d makes neutral breakers ganged with hots. So basically your breaker protecting 4 wires, 2 hots and 2 neutral, each hot one its own phase.

I have a small main lug load center QO with no main breaker. I dont want to get into it much but it is an old boat and factory back then considered boats to be Appliances plugged into shore power. So the shore breaker at the pedestal or where- ever was the only protection for the wires feeding power to the boat.

for reference if some dont believe me here. My old boat was wired up like this so it is what it is since 1970 and know one shocked or killed yet.
so perhaps just would like to add some circuit protection to the feed wires from the shore pedestal which shore power also has breakers. So would like to know what is available as in a square-d type box.
any added box is in a dry location under the deck away from the bilge.
lots of redundancy and money required are the new standards.

I like how these articles always make you feel substandard and sensational risk taking from what was done in the past. Like do it the way it was always before and now your dead.
like the breaker is 1/4 mile away in an office, never ever seen that yet. and to bring boat to current standards, simply start over again from scratch
http://www.boatus.com/boattech/casey/36.htm

Circuit Breakers
Factory shorepower in older boats too often omitted a circuit breaker. The thinking was that a boat was just another "appliance" plugged into the marina circuit, which was already-protected. But faulty marina wiring is too common to entrust your safety to an unknown breaker behind a dock office a quarter of a mile away. A safe AC system requires an onboard dual-pole breaker.

The breaker's rating must not exceed the service; i.e., a 30-amp inlet limits the main breaker to 30-amp. However, if the circuit directly supplies outlets in the cabin, the size of the breaker is limited to the outlet ratings--either 15 or 20 amps.

A single-circuit offers the benefit of simplicity, but if you need multiple AC circuits, breaker panels are available with a main breaker and two or more branch breakers. Despite being commonplace, it is not a good practice to combine AC and DC in the same breaker panel.

Polarity
Reversed polarity leaves your AC circuits unprotected if you have a single-pole main breaker since the breaker is now on the neutral side. Even with double-pole breakers, reversed polarity puts ON-OFF switches on the wrong side of the circuit, leaving OFF appliances fully energized. Be sure your AC panel is equipped with a polarity tester.

Where branch breakers are single pole, be sure they are on the "hot" side of the circuit.

 

[sdowney717]

I just was thinking you could use two 30 amp fused safety switches for this.
I already have one 30 amp square-d safety switch just sitting here unused.
Wonder If I could add 2 30 amp fuse block for the neutrals into the same box, otherwise just get another 30 amp fused safety switch

 

[walrus]

SQ D makes a switched neutral breaker but the neutral is simply switched on or off. I think for the most part the NEC forbids a breaker on the neutral. I believe you can do it with a handle tie so all conductors are either on or off with one flick of a handle in a circuit

 

[sdowney717]

ok, thanks then that wont work.
Then a standard 2 pole breaker would have each pole breaker-ed, just attach a white and a black one each respective pole, but then gets into box configuration issues with the power lugs could only handle 2 wires and takes 2 boxes, lot of waste of space to handle two 30 amp cords which has 4 wires you need to protect.

Starting to think a simple 30 amp inline fuse block, of 4 poles would do this ok.
I just hate fuses since you need to replace when blown.

Since the wire is 8 gauge, regarding those small cylindrical inline fuses take a 40 amp fuse? I would rather the marina breaker go than fuses blowing close to capacity.

 

[sdowney717]

I found some fuse blocks that use the large cylinder fuses and I have plenty of 40 amp fuses. Came from my inlaws old house panel from 1963. Looks like I can use these. mount them in a box.

So I will use 2 fuse blocks and each holds 2 fuses. They have pull handles, so you pull these out and can turn them around to off the circuit, if desired. Even though nothing has ever happened in 40 years, It is likely a good idea to fuse the incoming lines on the boat.
At least 40 amp wont blow constantly.
I have 8 gauge multistrand from shore receptacle to roary switch, and 6 gauge to the breaker panel.

 

[sdowney717]

seems like nothing ever gets tossed in our family

these have easy mounting holes.

 

[Keister]

Walrus is correct. No disconnecting means on the neutral (grounded conductor) is allowed in the code book except for fuel pumps at gas stations.

 

[Norcal]

Walrus is correct. No disconnecting means on the neutral (grounded conductor) is allowed in the code book except for fuel pumps at gas stations.

It is permitted to switch the neutral as long as is is switched with the ungrounded conductors, make/break at the same time, or the ungrounded conductors are disconnected 1st.

See NEC art.404.2(B) (2008 edition).

 

[justsam]

I am not a boater or an electrician so take this suggestion with that in mind.
It appears you are wanting to protect yourself from improperly terminated shore power, e.g. a hot neutral transposition. If that is the case, why not just a simple plug in detector for that condition, and if it is the case, than some type of adapter that transposes the hot and neutral at the shore interface? This would insure that your breakers are always on the hot side, and components, boxes, breakers, etc. are readily available for this.

 

[trainer]

those fuses and holders are out of an old fuse panel. You should mount them in some sort of enclosure to be safe.
Personally, I wouldn't use anything like that on my boat.

Another issue would be that if you got a weak fuse in the neutral side and it blew, then you may think the circuit is dead, but the hot would be energized and could complete the circuit to ground. In other words I think you may be creating more hazards than you are solving.

If it were my boat, I would leave everything as is, except to go a thorough inspection and maybe install ground fault breakers or recepticals.

Does anyone know if a GFI would trip if it detected reversed polarity?

 

[Norcal]

seems like nothing ever gets tossed in our family

these have easy mounting holes.

Those fusible pullouts came from a old ITE A/C disconnect.

 

[cowboyjosh]

those fuses and holders are out of an old fuse panel. You should mount them in some sort of enclosure to be safe.
Personally, I wouldn't use anything like that on my boat.

Another issue would be that if you got a weak fuse in the neutral side and it blew, then you may think the circuit is dead, but the hot would be energized and could complete the circuit to ground. In other words I think you may be creating more hazards than you are solving.

If it were my boat, I would leave everything as is, except to go a thorough inspection and maybe install ground fault breakers or recepticals.

Does anyone know if a GFI would trip if it detected reversed polarity?

Modern GFCI's bought after I think 2003 come from the factory "tripped" and if the GFCI is not wired correctly or is wired wrong, it will not reset. Also modern GFCI's will not pass power thru if the GFCI device is no longer operational.

 

[sdowney717]

the boat has a reverse polarity light and sonic alarm, so if the neutral would ever be energized, then they will provide a warning.

When you have a reversing polarity possibility like power cords, fusing the neutral is ok. And on a boat their new ABYC fangled codes demand it. They also have many newer code standards which my old boat would completely fail.

this is where neutral and hot must be trippable simultaneously.
and right now my power receptacles are greater than 10 feet away.

E-8.11.9.2 Simultaneous trip circuit breakers shall be provided in power feeder conductors as follows:
E-8.11.9.2.1 120 volt AC, single phase - ungrounded and grounded conductors (white),
E-8.11.9.2.2 240 volt AC, single phase - both ungrounded conductors,
E-8.11.9.2.3 120/240 volt AC, single phase - both ungrounded conductors,
E-8.11.9.2.4 120/240 volt AC, delta three phase - all ungrounded conductors,
E-8.11.9.2.5 120/208 volt AC, Wye three phase - all ungrounded conductors.
E-8.11.9.3 If the location of the main shore power disconnect circuit breaker is in excess of three meters (10 feet) from the shore power inlet or the electrical attachment point of a permanently installed shore power cord, additional fuses or circuit breakers shall be provided within 10 feet (three meters) of the inlet or attachment point to the electrical system of the boat. Measurement is made along the conductors.
E-8.11.9.3.1 If fuses are used in addition to the main shore power disconnect circuit breaker, their rating shall be such that the circuit breakers trip before the fuses open the circuit, in the event of overload. The ampere rating of the additional fuses or circuit breaker shall not be greater than 125% of the rating of the main shore power disconnect circuit breaker. For 120 volt service, both the grounded and ungrounded current carrying conductors shall be provided with this additional overcurrent protection.
E-8.11.9.4 If required, overcurrent protection for power-feeder conductors from AC generators and inverters, shall be within 7 inches (180 mm) of the output connections or may be within 40 inches (1.0 meter) of the output connections if the unprotected insulated conductors are contained throughout their entire distance in a sheath or enclosure such as a conduit, junction box or enclosed panel.

and this one.

E-8.5.5 When more than one shore power inlet is used, the shore power neutrals shall not be connected together on board the boat.

which I wonder since that would require a 4 pole transfer switch from shore to gen set to inverter. Twin 30 amp shore power feeders have 2 hot and 2 neutral bundled in separate cords. Even though ALL neutral are grounded and I assume tied together in the marina wiring, for each feeder, they want it separate on the boat.
Sometimes I think they wish to make changes just to make changes and keep up sales of equipment.

a list of excerpts from ABYC code book.
http://www.cruisersforum.com/forums/f14/excerpts-from-abyc-electrical-1471.html

 

[sdowney717]

A hypothetical question

consider a boat twin 30 amp shore power feeder wire running to a main breaker and then on to a breaker panel.
each shore power feeder has a hot, neutral, ground wire.
ABYC says both neutral and hot need to be breakered and simultaneously tripped if shorted.
Neutral requires ocpd because a shore cable could be wired wrong and neutral could go hot.

Now for a main breaker disconnect, I was thinking what about using a GFCI breaker in a 2 circuit load center.
Each shore power feeder cable goes into a load center
inside the load center, incoming feeder put one hot on one lug, one neutral on other lug, outgoing same thing for each breaker lug.
Now you could just use a 2 pole breaker in the load center.
But lets say you want to GFCI each hot wire.
CAN YOU DO THIS BY
using a single 1 pole GFCI 30 amp breaker for the hot wire
using a single 1 pole standard 30 amp breaker for the neutral wire
Take a handle tie GE part #THT104 tieing the breakers handles together

Now if you have a ground fault in the hot wire, the breaker will trip.
and also simultaneously disconnect the neutral.
As well as have ocpd working.

 

[mrb]

no. Also, i wouldnt expect a GFCI supplying the feed to an entire boat to stay untripped often due to cumulative leakage. GFCI is normally used at the branch circuit level for this reason.

why the twin 30 amp cords? why not just upgrade to 50 amp 4 wire feed if you need more than 30a / 120v?

are sqd panels used in boats anymore? I thought everything was marine specific equipment now such as those made by paneltronics

 

[sdowney717]

nuisance tripping I dont like, cumulative leakage, maybe if it was wet? This is a boat that is a sedan cruiser. Cabin stays dry. Only time I had an electric problem was when window was open out on the water, a port side outlet had sea water from big wave action.
Although it can get very humid in the boat. I thought GFCI the entire shore power would be pretty safe.

those GE handle ties still allow the breakers to trip?
Can those ties handle gang a GE GFCI THQL breaker to a standard THQL breaker?

"are sqd panels used in boats anymore?"

only on old boats

boat currently has a square-d QO 8 space panel with main lugs. OEM.

 

[sdowney717]

why the twin 30 amp cords? why not just upgrade to 50 amp 4 wire feed if you need more than 30a / 120v?

purely monetary reasons. For example just this little 4 pole guy here is $400
which technically new ABYC regs would require to keep neutrals from tieing together.
http://www.pacergroup.net/ItemForm....Category=7b86d12d-a783-4c6d-84ce-b17416ccde99

the 50 amp shore cords ,receptacles and plugs would be another $400 or $500 or more.

here just a new cord is $630, got to be long enough to be worthwhile.
http://www.overtons.com/modperl/pro...d&i=92801&r=view&aID=601S7&cID=SHOPPING_92801

 

[mrb]

you cant tie the neutrals from the 2 seperate 30 amp cords together. all sorts of problems both code and in practical use. this is just a backwards, hokey, dangerous way to do this. there is a device made by hubbell to safely combine two 30 a feeds but its expensive and still isnt ul listed.

another way to do this, and what I would probably do if forced to and couldnt do it right, is to have two loadcenters one for each input. Neutrals kept seperate, grounds tied together. Have a 30A Y cable if there is only one 30a shore power available.

 

[zmaxmotorsports]

Back in the day neutrals used to be on fuses on a houses around here,Im thinking most of those old boxes were from back in the 50s.
At some point somebody realized that popping a fuse on a neutral while the hot side was still feeding the circuit was a good way to create a power surge/cooked appliances and or a burned down house.
Im not sure about on a marine application like that,maybe check mike holts site.

 

[sberry]

At some point someone figured tripping a N left the circuit still energized, not sure about surges, this is a relatively new phenomenon.

 

[sberry]

Buy a new cord and do it right.

 

[theoldwizard1]

Related to this discussion, will a post-2003 GFCI breaker trip and/or not reset if it is FED with reverse polarity and there is no load ?

EDIT: Well, partially answering this question, UL943 DOES require that GFCI protect against reverse polarity ! I assume this means breakers, outlets and switches.

Yes, the Leviton 7590 is a "switch" ! In stead of having a toggle or rocker, it has the typical GFCI outlet "Test" and "Reset" buttons. It is rated at 20A and 1.5hp. This could be useful in some application !

 

[Stuff]

Yes, the Leviton 7590 is a "switch" ! In stead of having a toggle or rocker, it has the typical GFCI outlet "Test" and "Reset" buttons. It is rated at 20A and 1.5hp. This could be useful in some application !

Do you have anything from Leviton that says these are designed for switching duty?

 

[zmaxmotorsports]

At some point someone figured tripping a N left the circuit still energized, not sure about surges, this is a relatively new phenomenon.

When you have power in a circuit but lose the neutral you will start smoking electronics in short order.
Whether its the neutral coming from the pole or a lost neutral at an outlet,same result if something is plugged in with the switch on.
I consider that to be the same as a surge,maybe Im using the wrong wording.(its been known to happen)

 

[theoldwizard1]

Do you have anything from Leviton that says these are designed for switching duty?

No, but the current and motor rating are right from them.

 

[DC73]

Nothing like resurrecting a 5 year old dead thread to advertise your business with your first post. Fail.

DC

 

[zmaxmotorsports]

At some point someone figured tripping a N left the circuit still energized, not sure about surges, this is a relatively new phenomenon.

Read the tale of woe post,Thats exactly what I was referring to.

 

[sberry]

When you have power in a circuit but lose the neutral you will start smoking electronics in short order.
Whether its the neutral coming from the pole or a lost neutral at an outlet,same result if something is plugged in with the switch on.
I consider that to be the same as a surge,maybe Im using the wrong wording.(its been known to happen)

Consider it what you want but N is switched all the time, this is AC but more importantly maybe here is the endorsement of a brain fart and that isn't a shot at the op but others jumping on with a big you go girl.
If this was a mobile home and someone came up with this, can't afford something something so they gonna cobble they would be hung but,,,, a guy is doing this mostly for monetary and 400 here and there,,, so he can save some jack in his cabin cruizer at the marina and it starts to be a good idea. Turns in to a tech talk about neutral and surges instead of being pointed out that mr cabin cruiser should buy a wire and the correct recept.

 

[sberry]

Switching a n on a 120v circuit is not the same as losing n on a multi wire service.
Whoops, my bad, it really isn't a neutral on a 120v.

 

[wyliesdiesels]

Switching a n on a 120v circuit is not the same as losing n on a multi wire service.
Whoops, my bad, it really isn't a neutral on a 120v.

True. But switching a neutral while leaving thr ungrounded/hot conductor live sets up a dangerous potential.

 

[NUTTSGT]

Nothing like resurrecting a 5 year old dead thread to advertise your business with your first post. Fail.

DC

Yes and they are now gone.

 

[sberry]

True. But switching a neutral while leaving thr ungrounded/hot conductor live sets up a dangerous potential.

Yes, its the point.

 

[nadogail]

Marine (ships and boats) electrical systems are very different than Shore Side (buildings) systems.

What is done on a ship, with an ungrounded system, for Safety reasons would be very dangerous if done in a building. Ships and boats do not have grounded neutral conductors.

I have a Marine Electrician Journeyman Card.

 

[sberry]

Sure, l spose it would make the hull a giant current carrying conductor. There may be multiple power plants too.

 

[sberry]

I have a Marine Electrician Journeyman Card.

I got a bud works in Pascagoula, may have shifter to Caterpillar now but I was chatting about something and got the idea there is their own way of doing things. I mentioned something about residential and he got a glazed look.