ABYC Power Feeder Code E-8.11.4.1 vs E-8.11.9.2.1

[sdowney717]

E-8.11.4 Each transformer shall be provided with overcurrent protection for the primary circuit that also provides protection for the secondary winding(s).
E-8.11.4.1 This overcurrent feeder protection device shall open all primary feeder conductors simultaneously, and
E-8.11.4.1.1 it shall be rated at not more than 125% of the rated primary current of the transformer.
EXCEPTION: Feeder conductors for 120/240 volt primary circuits require protection only in the ungrounded conductors.



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),

http://www.cruisersforum.com/forums/...ical-1471.html

I am somewhat confused on this.
My situation is the old boat has no fuse or breaker in the AC shore power main feeder line. And the shore receptacle is more than 10 feet away from the shore-gen-off rotary selector switch. It does have polarity alarm and polarity light.

So I plan to put in a breaker. Does this breaker need to trip both neutral and hot (double pole)simultaneously or just the hot (single pole)?

10 foot rule, I understand

Quote:
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.

[St. Elsewhere]

Your question: "Does this breaker need to trip both neutral and hot (double pole)simultaneously or just the hot (single pole)?" implies that your boat is wired for a 120 volt service and not a 120/240 volt connection. If true you want to install a two pole breaker connected to the single hot conductor and the neutral conductor.

The 120/240 volt arrangement would have two hot conductors.

[sdowney717]

thanks, yes it is 120 volt only. That is my original plan.

But what are they talking about here
grounded seems to mean white in one place and ambiguous in the other place of this code.

E-8.11.4.1 This overcurrent feeder protection device shall open all primary feeder conductors simultaneously, and
E-8.11.4.1.1 it shall be rated at not more than 125% of the rated primary current of the transformer.
EXCEPTION: Feeder conductors for 120/240 volt primary circuits require protection only in the ungrounded conductors.

E-8.11.9.2.1 120 volt AC, single phase - ungrounded and grounded conductors (white)

if you just read this as written, then it is not saying the same thing at all.

[St. Elsewhere]

I think that "Feeder Conductors" include the hot leads and the neutral, but exclude the green ground wires. The neutral is grounded typically at the head of the dock. So maybe that is why they refer to ungrounded conductors. Boat installations with isolation transformers are not tied to the shore ground wiring, and the neutrals and hot leads in the boat are only magnetically connected to the shorepower.

[sdowney717]

so your thinking E-8.11.4.1 has only application in relation to an isolation transformer on the boat, if you have that setup.
so the ungrounded (black) wire would be the only required one to have the breaker. And no wire on the white grounded wire off an isolation transformer.

Makes you wonder though what about the feeder wire into the transformer? I would think both grounded and ungrounded wires would need double pole breaker. And then another one on the transformer output but only a single pole on the hot wire.

That is somewhat sensible, but these excerpts
http://www.cruisersforum.com/forums/...ical-1471.html
dont have subtitles saying this set of code go with isolation transformer and this other set go with the shore power feeder line. So creates confusion IMO.

Yes, grounded current carrying wire would be the white one.

[GordMay]

In North America, you need a double-pole main AC breaker.
For a 120V 1phase (2 wire) system, pictured below, the breaker will be on the black (ungrounded) & white (grounded) conductors.
For a 120/240Volt 1 phase (3 wire) system, the breaker will be on the black (or blue) ungrounded & red ungrounded. It's common to find both "hot" ungrounded wires are actually black.
The green wire is the ground or grounding wire.

[s/v Jedi]

Originally Posted by sdowney717

if you just read this as written, then it is not saying the same thing at all.

No, ABYC is a bit confused. This happens now and then after they woke up to find new technologies in use on boats.

ciao!
Nick.

[sdowney717]

I have a polarity indicator on the boat which is just a separate neon type light and an alarm buzzer.

But could you simply not use this single item here?

Ebay item number 140514125044

Safe alarm ac 110 Mini Siren buzzer lamp

[sdowney717]

For a 120/240Volt 1 phase (3 wire) system, the breaker will be on the black (or blue) ungrounded & red ungrounded. It's common to find both "hot" ungrounded wires are actually black.

why not a 3 pole breaker including the neutral grounded?
less chance of a miswired cord where the neutral goes hot?

so a twin 30 amp need 2 double pole but a single 50 amp only needs one double pole.

[donradcliffe]

Originally Posted by sdowney717

I have a polarity indicator on the boat which is just a separate neon type light and an alarm buzzer.

But could you simply not use this single item here?

Ebay item number 140514125044

Safe alarm ac 110 Mini Siren buzzer lamp

The reverse polarity indicators can trip GFC breakers if they draw too many milliamps.

[sdowney717]

The reverse polarity indicators can trip GFC breakers if they draw too many milliamps.

could be, the breakers I will install for the mains wont be GFCI.
As it shows on that shore power diagram, the polarity indicator comes after the mains.
I do have all outlets GFCI protected, but nothing else is.

[btrayfors]

ABYC is not "a bit confused". You just have to read CAREFULLY.

A 120V single-phase circuit has:

1. the "hot" or "ungrounded" wire (black);
2. the "neutral" or "grounded" wire (white); and
3. the "grounding" wire (green).

By contrast, a 120/240 volt single phase system has no neutral. Oops...not true. See correct post #15 below.

It has:

1. the "hot" or "ungrounded" wire for line #1 (black);
2. the "hot" or "ungrounded" wire for line #2 (red); and
3. the "ground" or "grounding" wire (green).

You get 120 volts between either of the "hots" and the "grounded" or "neutral".

In ABYC parlance, "ungrounded" means "hot".

Bill

[Maine Sail]

The requirement is for any white, black or red AC wire to be broken by the circuit breaker.

I relation to AC wiring the ABYC makes a distinction between grounded (white) and grounding (green) and ungrounded (black or red). While there are other acceptable colors for AC wiring white, red, black & green are what you'll normally see and all but green, groundING not grounded, need to be broken by the breaker.

The green grounding wire should not be interrupted..

EDIT: Looks like Bill & I responded at the same time with basically the same answer...

P.S. Bill, your forgot a wire in your 120/240 system description. There is always a white grounded wire as green is never intended to be a return path unless there is a fault. Should have White, Black, Red & Green in a 120/240 system..

[s/v Jedi]

Originally Posted by btrayfors

ABYC is not "a bit confused". You just have to read CAREFULLY.

I'm afraid you didn't read the 1st post carefully enough

they are confused, because they first say only the ungrounded conductor of the 120V connection needs a breaker and later state both grounded and ungrounded conductors of a 120V connection need a breaker.

ps. my 120/240 wiring has 4 conductors and include a neutral... I think every boat has that as does the marine plugs and shorepower cables.

ciao!
Nick.

[btrayfors]

Nick,

Well, the way I read it they're talking about 120/240 volt circuits only (the bold print) which require CPDs in the ungrounded wires only.

And, I misspoke...sorry. The 120/240 volt single phase systems usually found in marinas are indeed 4-wires, and include a white shore-grounded neutral conductor.

And, by the way, I agree completely: all AC feeder circuits should break both the hot and the neutral wires, not just the hot.

The rum got to me early today :-)

Cheers,

Bill