ABYC Power Feeder Code E-8.11.4.1 vs E-8.11.9.2.1

[Maine Sail]

Originally Posted by s/v Jedi

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.

In a 120V system feed they require breaking the white (grounded) & black (ungrounded) and in a 120V/240V feed they require breaking only the red & black (ungrounded conductors). The OP has a 120V system therefore should be breaking the white & black on a trip.


E-11:

11.10.2.8.2 Simultaneous trip circuit breakers shall be provided in power feeder conductors as follows:

11.10.2.8.2.1 120 volt AC, single phase - ungrounded and grounded conductors (white),

11.10.2.8.2.2 240 volt AC, single phase - both ungrounded conductors,

11.10.2.8.2.3 120/240 volt AC, single phase - both ungrounded conductors,

11.10.2.8.2.4 120/240 volt AC, delta three phase - all ungrounded conductors,

11.10.2.8.2.5 120/208 volt AC, Wye three phase - all ungrounded conductors.

[sdowney717]

11.10.2.8.2.3 120/240 volt AC, single phase - both ungrounded conductors,

yes, but why not ALSO the grounded (white) conductor for 120/240 systems?

ungrounded -ungrounded (black to black) is 240 volts potential

ungrounded - grounded (black to white) is 120 volt potential

They are saying this white is breakered in a 120 volt shore power but is not in a 120-240 volt setup. to me to be consistent, then should be a 3 pole breaker opening hot, hot, neutral.

boat will have 240 AND 120 volt appliances used
See what I mean?
Any ideas why they dont care in this situation?

[donradcliffe]

Originally Posted by sdowney717

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.

It ain't your breakers that are going to trip--its the ones on the dock.

[St. Elsewhere]

Take another look at the ABYC reference cited in the OP:

Quote:
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),

E-8.11 is talking about transformer protection. Such transformers connected to a shore power source are typically for isolation and 208 vs. 240 volt boosting needs. The primary winding of such transformers only need the two hot leads. The secondary would have the center tap for the neutral to be connected, and the two hot connections. I believe that is why the exception applies to this case.

[s/v Jedi]

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

You might well be right, meaning that ABYC will not require 3-pole breakers for 120/240V installations. This shows that their requirements are not enough now and then because all will agree every hot and neutral conductor should be on the breaker. You don't even know which conductor will be neutral or hot when you first connect to an unknown dock outlet... I've seen it all, incl. swaps between neutral and ground.

ciao!
Nick.

[sdowney717]

You might well be right, meaning that ABYC will not require 3-pole breakers for 120/240V installations.

yes very inconsistent.
I know square-d makes 3 pole breakers so these things can exist.
Anyone think ABYC just did not suggest a 3 pole breaker because the manufacturers of boat panels dont make them?

for example
Square D QO350VH Circuit Breaker,plug-in,3 Pole,50a

although not sure if the panel would make sense. I would have to look at one to understand what it does.

some breakers are neutral switch off breakers
QOR/QOB Circuit Breakers, 3-Pole, Bolt-on - ZORO tools

[sdowney717]

It ain't your breakers that are going to trip--its the ones on the dock

Are these really gfci on the power pedestals now?
perhaps only in modern updated marinas.
If the shore power is gfci, does this mean that having any gfci outlets on the boat is not needed?

At the slip where I am now, we have only standard duplex sockets with free power. A few owners have had a meter put in and can hook up to a decent power source, most do not.

10 years ago at Southhall Landings across from Salt Ponds marina we had 50 amp power, but I dont think they were gfci then.

[sdowney717]

http://www.qualitymarineservices.net/safety.html

just reading this suggests the 30 amp plugs are not gfci

. So, you get a hold of an adapter that plugs into a 30 amp twistlock receptacle on the shore pedestal and off you go. Problem here is that you have just plugged into a receptacle that is not protected by a GFCI!

so does this mean you cant replace your own shore power cord ends anymore?

NFPA 303 clearly states that add-on plugs and electrical tape on shore cords are prohibited. How many like this do you normally see in your marina? We have documented cases where the improper assembly of replacement plugs caused fatalities.

[DotDun]

Originally Posted by sdowney717

Anyone think ABYC just did not suggest a 3 pole breaker because the manufacturers of boat panels dont make them?

The Blue Sea 3104 is a 50A 3-pole ELCI.

50A Triple Pole Residual Current Circuit Breaker (ELCI) - PN 3104 - Blue Sea Systems
or
Blue Sea Systems Offers Solutions for Mounting ELCI Breakers to Comply With ABYC July 2010 Requirements - Resources - Blue Sea Systems

[s/v Jedi]

Yes, it's not hard to find the 3-pole breakers today but I do believe the situation was different in years past and ABYC has a track record of lagging a bit. Get the 3-pole breaker

ciao!
Nick.

[St. Elsewhere]

Three pole breakers are used in all three phase circuits, and they have been around for many decades, probably longer than any of us have lived.

They are not required under ABYC E-8.11.4 because there are only two ungrounded conductors involved in the primary of the transformer which is the focus of this regulation. There is no center tap neutral on the primary winding, hence no neutral to be connected to a third pole.

Here is a link to a diagram and wiring instructions for such a device: http://www.charlesindustries.com/mar...soboo1_pr5.pdf.

Scroll down to page six, and look at Figure 1.

You will see a two pole breaker on the primary side of the transformer in perfect harmony with ABYC. Note the the shore power neutral is not connected at all. Also, note that the ground wire is connected to the transforner shield and that the sheild is isolated from the transformer case.

The purpose of isolation transformers is to seperate the boat ground and neutrals from the shore ground.

[sdowney717]

They are not required under ABYC E-8.11.4 because there are only two ungrounded conductors involved in the primary of the transformer

not everyone has a transformer
so shore power neutral is current carrying in a 120/240 volt setup.

[St. Elsewhere]

Originally Posted by sdowney717

not everyone has a transformer
so shore power neutral is current carrying in a 120/240 volt setup.

Of course. then you would not be under ABYC E-8.11.4, which was raised in the OP, and applies to transformenrs.