AC Circuit Breaker

[Ron20324]

( from Stu): I recommend that it be replaced with either a single or double pole breaker, with the ground directly connected, i.e., NOT on or through a breaker. The double pole (hot and neutral) breakers are required by the newer AYBC Code. Single pole breakers (on the hot [back 120V] leg) were fine for many years earlier. Since Blitz obviously has room behind his panel for a multiple-bank breaker, he should use the newer two pole breaker. The double pole breakers are NOT linked, that's why there are two "handles" and both need to be moved, one can be moved and the other will stay where it is unless moved by hand - that's why there are two of them there.

Stu, thanks for the research. I know it's time consuming. I should be down vacuuming the sawdust out of the boat from the last two projects, but here I sit at the keyboard.... The AC main MUST be a double-pole type, according to ABYC, and the double-pole breakers for AC mains need to be linked. In the Blue Sea electrical catalog, every AC main breaker they have shows the toggles linked so they MUST be operated at the same time. If using two individual breakers, a bolt through the toggles will do the same thing. If either breaker trips, it will shut the other one off with it. Correct on the ground- never disrupt it!

 

[Stu Jackson]

Ron, just parsing here, so bear with me

...Page 150 of the Calder's bible tells us the ABYC REQUIRES an RPI device to be wired in such a way as to be permanently lit or audible in the event of reverse polarity. That does not happen if it's on the load side of the breaker. Think, also, if the power is reversed, that every neutral wire on the boat is now at 110 volts via the neutral buss. Me, I think it is common sense- as per the books- to have the RPI BEFORE the main AC.

It really does matter, and that is "why", according to the books. I suggest everyone who has replied to this thread read Calder (or anyone) who is considered the authority on this or any subject.

...unless the poster has read- and can quote- their source of knowledge.

Thanks, Ron,

I have the 2nd edition, so I think you're using the 3rd edition, because the pages I have don't relate to your references, sorry.

Parsing:

One could submit that "...in such a way as to be permanently lit or audible in the event of reverse polarity..." could well mean "before being used." If the main breaker is off, the outlets or appliances aren't being used. If the main breaker is ON, the appliances MAY not be being used. Doesn't matter where the RPI lights are as long as they are there before the the A.C. circuits are being used.

Just "opinionating" here, having dealt with electrical codes all my professional career.

Ron, of course you're right in quoting sources, which is why you're right about doing the "research" and quoting facts not opinions. That's why I keep providing links to authoritative sources.

What's happening here is that Codes are continually being updated and upgraded for additional safety issues.

As you say, the actual LARGER issue is that folks should, at the VERY least, understand what reverse polarity MEANS. We've had discussions on our C34 mb, where, on my boat, for instance, there are three lights: two say it's OK, and the other two say it's reversed. One of our members wrote in to say his lights were lit? Ah, yes, but which ones? Very important.

 

[Blitz]

In as much as the reverse polarity indicator (RPI) is there as a safety indication, I see no reason why it is not wired to make it's indication BEFORE you throw that AC main breaker. It's only a matter of wiring it on the line side of the breaker instead of the load side. Sure, most AC things will function. You just never know what might happen if the shore power is reversed and 110 allowed into the boat helter-skelter (that's an electrical term). That's why the indicator is there, and it is cheap insurance . And you use the key word that "usually" the AC appliances are off anyway. It's the "unusual" killer 110-volt situations we must protect ourselves from.

Ah-ha. Found the Calders's. So big and thick, I thought it was the Chapman's. Page 150 of the Calder's bible tells us the ABYC REQUIRES an RPI device to be wired in such a way as to be permanently lit or audible in the event of reverse polarity. That does not happen if it's on the load side of the breaker. Think, also, if the power is reversed, that every neutral wire on the boat is now at 110 volts via the neutral buss. Me, I think it is common sense- as per the books/abyc- to have the RPI BEFORE the main AC.

quote]

Ron/Stu; It is currently wired so that the reverse polity or normal light shines before the CB it switched on - this much I know.

 

[Ron20324]

Yes, it is 3rd edition. No doubt issue 4 will negate all this anyway.... I did not include the total ABYC requirement part that says, quote: " the normal way is to wire a light or buzzer from the INCOMING (my emphasis-ron) neutral wire to the grounding wire". It does say "normal way". So, read it as you see it for yourself.

When I put in a larger AC panel on my new Beneteau, I made an LED light to just indicate shore power was coming to the panel. Flip the main, and another came on to show breaker activation. Of course the RPI was wired to the line side of the breaker neutral and ground. I did the same lighting arrangement for the inverter AC.

Thanks, Ron, I have the 2nd edition, so I think you're using the 3rd edition, because the pages I have don't relate to your references, sorry.

Parsing:

One could submit that "...in such a way as to be permanently lit or audible in the event of reverse polarity..." could well mean "before being used." If the main breaker is off, the outlets or appliances aren't being used. If the main breaker is ON, the appliances MAY not be being used. Doesn't matter where the RPI lights are as long as they are there before the the A.C. circuits are being used.

Just "opinionating" here, having dealt with electrical codes all my professional career.

Ron, of course you're right in quoting sources, which is why you're right about doing the "research" and quoting facts not opinions. That's why I keep providing links to authoritative sources.

What's happening here is that Codes are continually being updated and upgraded for additional safety issues.

As you say, the actual LARGER issue is that folks should, at the VERY least, understand what reverse polarity MEANS. We've had discussions on our C34 mb, where, on my boat, for instance, there are three lights: two say it's OK, and the other two say it's reversed. One of our members wrote in to say his lights were lit? Ah, yes, but which ones? Very important.

 

[Stu Jackson]

Change: Correction : Don't break the neutral

Blitz, Ron, and all,

This discussion got me to thinking some more, and I went back into my last ten years' of saving material on my computer. I found this, most of which was written by a good friend, and an electrical engineer who has great experience in building, railroad and boating electrical systems. This material is from 2002 & 2003, but not much has changed since then.

I take back almost everything I've said on this, so far! It could well be that Blitz's original arrangement may not have been so bad after all!

All yours:
Reverse Polarity Summary

The reverse polarity light is connected between the white wire of the ac power pair and the green wire, which is a safety ground. The white wire, or neutral, is grounded at the electrical service entrance to the marina and by the power company at the distribution transformer. Thus if polarity is correct, it will always be at ground potential and the light will be dark. If polarity is reversed, there will be something close to line voltage (115 ‑ 120 volts) between the white wire and green ground wire, lighting the reverse polarity light. Your green wire is, as indicated above, a safety ground (the round pin in a three prong plug or "hooked" blade in a twistlock plug) and does not normally carry any current. It is grounded in many places throughout the electrical supply system. However, it definitely must not be grounded anywhere in your boat or all sorts of safety and electrolysis problems can occur.

The danger in having polarity reversed occurs for two reasons. First, electrical appliances are constructed with the premise that the white wire will always be at ground potential and the black wire will be "hot." Thus all appliance power switches will be in the black lead and disconnect the "hot" side of the line so the appliance will be "dead" when the switch is off. Second, anyone working on the ac power system in the boat would naturally assume that if the main switch (in the black lead) is off, the power is disconnected and it is safe to work on the wiring. With polarity reversed, the switch would be in the neutral or ground potential wire. Thus the switch would be in the wrong lead and would not disconnect power from the system. The wiring in the boat would still be "hot" even with the switch off.

If you have a poor connection in the white (or neutral) wire due to a loose plug and appliances are on, current will flow from the black "hot" wire, through the appliance and back to the white neutral wire so it will be "hot" too. Thus your reverse polarity light will come on even though polarity is not reversed. It certainly is possible that there could have been a break in the white neutral wire somewhere in the marina or dock wiring which would cause the same thing to occur. However, since reattaching your shore power cord fixed the problem, this is more likely the cause.

As to a recommendation that you put a switch in the white (neutral) wire, this is specifically prohibited by the US National Electrical Code as well as the Canadian Electrical Code. For the above indicated reasons, it is essential that the neutral NEVER be broken.

It certainly isn't my desire to get into any arguments on the issue of using a single pole or double pole breaker on the ac service. This has been a point of controversy nationally in electrical standards group meetings for some years. I can explain the issues and you will have to decide for yourself. The controversy arises as to whether the boat is considered an "appliance" in which case a double pole breaker is considered acceptable. However, if it is considered an extension of the shore power system, it is not acceptable. The concern in using a breaker in the neutral (white) lead is that it can open independently from the breaker in the "hot" (black) lead and leave the neutral wiring in the boat "hot" as explained in my previous note. This is the argument put forth by those favoring considering the boat system as an extension of the shore power system. Virtually all commercial breakers rated for ac power service which have screw terminals are single pole. To make them double pole, two single pole breakers are usually ganged with their toggles mechanically attached so that if one breaker trips, it will trip the other. Even if the two breakers are contained within the same enclosure (as, for instance, the Square D type QO) the breakers are still separate so the size will be double that of a single pole breaker. Consequently, you will not find a double pole ac power breaker in the same size package as a single pole breaker.

As I indicated in my initial reply, it has always been considered fundamental that the grounded neutral in a power system never be broken for any reason. Doing so will cause the entire downstream ac system, neutral and all, to be "hot" if any appliance on the circuit is turned on. This can cause a safety problem as both appliance manufacturers and electricians expect the neutral to be at ground potential.

For a number of years ‑ up until around 1988 I believe ‑ the ABYC followed this standard and boat builders put a single breaker in the "hot" side of the line. There has been a somewhat heated internal debate within the national standards committees about how the neutral should be handled for semi‑permanent electrical installations ‑ specifically whether to break both the "hot" and neutral or just the neutral. This would cover such things as earthmoving equipment, trains when connected to "shore" power and, of course, boats. If these are considered to be extensions of the power distribution network, you would not break the neutral. If, however, you consider them to be big appliances, then you would break both the "hot" and neutral. What apparently tipped the balance for the ABYC was the potential liability concern of a discontinuity in the marina shore power system which would (and did in at least one instance) cause the neutral on the whole dock or marina to be "hot." Having a double break in the ac line totally disconnects the entire boat system and the builders could point out in any litigation that they had acted responsibly in providing total isolation.

We in the rail and transit industry still use only a single break in the "hot" side of the line for a cord connected semi‑permanent remote ac installation. This is also my personal preference as it assures that a breaker failure and/or the additional electrical connections it involves will never break the neutral. I've seen too many of these to totally trust the breakers. Also, there is a mechanical linkage between the two individual breakers making up a double‑pole pair which is supposed to tripboth if either trips. I've seen this fail due to sloppiness in the tie‑bar between the two handles and/or breaker failure. The Square D type QO breakers make this mechanical tie internally to mitigate this problem, but virtually all others use two mechanically identical breakers with a tie‑bar on the toggles. Codes require physically separate breakers as these are typically used on either a split‑phase 120‑240 Volt or three‑phase system where there is line voltage between the poles. I might add that this is why it is impossible to get a two pole breaker in the same size package as a single pole breaker.

The reverse polarity light, when provided, is connected between the neutral (white) and safety ground (green) wires. If cord polarity is normal, there will be no potential between the neutral and ground. If it is reversed, the neutral will be "hot" relative to ground and the light will be on. Same thing is true if there is a break anywhere in the neutral (either marina or shore power line) which is what apparently happened in Ken Jones' instance. I was unhappy to see that "bending the prongs" of the plug was the "fix" which was applied. If there was a problem in the receptacle or shore power cord which resulted in a break in the neutral, it should have been remedied by replacing the offending component. Risking electrocution is not something to trade off on saving money.

Catalina, and most other boat manufacturers worldwide, today use a three pole breaker for the ac line. This is recommended by the ABYC and required by EC (European Common Market) standards. Two poles break the "hot" and neutral and are rated for the capacity of the shore power cord. The third is connected between the neutral and safety ground (green) wires and rated at a lower current ‑ typically 5 amps. If you have polarity reversed or a break in the neutral, current will flow in this breaker and trip out all three, isolating the boat system. This is the only way I would recommend using a multiple pole breaker which breaks the neutral. Actually, my preference is a double pole breaker with one in the "hot" lead and the other wired between the neutral and safety ground. That's the way I rewired my 1989 C‑34. For this I ganged a 30 amp and 5 amp breaker and used an engraved "patch" panel over the existing panel to dress up the larger cutout.

The EC standards of today go even one step further in requiring an isolation transformer for all on‑board ac wiring in recreational boats. Of course they use 240 Volts rather than 120 Volts as we do, so the electrocution potential for a fault condition is a lot greater over there.

Hope this clears up more questions than it raises. Handling the ac power on a boat is fraught with all sorts of potential safety problems. There is really no "perfect" way to do it short of a transformer which totally isolates the boat neutral from the outside world neutral. This requires a 3.6 KVA transformer for a 30 Amp, 120 Volt service which is a big and expensive item. The European boats typically use a 13 Amp, 240 Volt service and a 2.5 or 3.0 KVA isolation transformer. Even this is a pretty big unit and cost is around $150‑200.

The above only deals with the safety aspects of the ac power. There are also a huge number of potential pitfalls for electrolysis problems as well. One could write a book on this but, unfortunately, that would be REALLY controversial as it is as much an art as a science and involves both the boat system and the marina system as well. Electrical potentials which would be physiologically negligible can cause devastating results electrolytically in salt water.

As to the flashing ac power indication lights noted by newsgroup members, these are neon lamps which typically have a fairly long life but eventually fail. They can even do so without being illuminated if the glass‑metal seals for the leads leak. As the neon gas pressure drops in the lamp, it starts flashing. Thus a flashing neon lamp is the first sign of a lamp failure. Thus if you see either the ac power indicator lamp or the reverse polarity lamp flash intermittently, it should be replaced. Unfortunately, there is no safe way to simulate reverse polarity or a broken neutral conductor so reverse polarity lamps cannot normally be tested. That's another reason why the safety breaker noted above is a better way to go
than an indicator lamp.

...I checked out the electrical systems on a number of Catalinas.
With 225 boats in the marina, there are quite a few Catalinas of variousvintages around. I know most of the owners and also the service staff wellso access is no problem. Seems that all the earlier boats (C‑30, C‑34 andC‑36) are wired with a single pole breaker in the hot shore power lead and a continuous neutral. Starting with the 1988 C‑30 and 1990 C‑34 and C‑36 they went to a three pole shore power breaker which breaks only the hot lead and uses the other two breakers to operate the reverse polarity light and force the breaker to trip if current flows between the neutral (white) and safety ground (green). Then around 1996 or 1997 they went to a two pole breaker which breaks both the hot and neutral leads. There is a reverse polarity light, but it no longer forces the breaker to trip if polarity is reversed.

I gather from the above that there was some differences of opinion as to just what represents a "safe" system. My guess is that the later (and
presumably current) philosophy is that it reduces the potential liability if they totally disconnect the boat from shore power when the breaker is operated. I can't think of any other reason to break the neutral. Personally, I like the three pole breaker scheme where the neutral is continuous and the breaker is forced to trip if current flows between neutral and safety ground. It's been beaten into my head for so many years that you NEVER break the neutral that I have trouble accepting a system that interrupts it.

Certainly either the three pole breaker or the double break scheme would be better than the single pole breaker used on the earlier boats. It's interesting that the 1988 C‑30 uses the three pole breaker while it was not introduced on the C‑34 and C‑36 until two years later.

I have to get in touch with Seaward (who I believe makes the Catalina
panels) about some propane tank matters and will ask them about the breaker arrangements. The multiple pole breakers are internally ganged with a single toggle and these are about the only ones I've ever seen of this type. There is no manufacturer's name or part number on any of them on the boats I looked at.

[search togs: reverse polarity, multiple breakers, ganged breakers, reverse polarity lights]

 

[Ron20324]

Stu, that's quite a sermon that only points out that too much said here is personal, opinion, or preferences. The US National Safety Code does not apply to boats. The ABYC is not mandated as gospel, but more like they are only guidlines that a person would do well to adhere to nonetheless. Unless things have changed since a previous thread on this matter, the Coast Guard is the only agency that can mandate anything required on boats. And as we know, they do not go far enough in some cases. I do not have a copy of the ABYC, though I know there is someone on these forums who does, but I accept Calder's offering as to what the ABYC says: "It is an ABYC and ISO REQUIREMENT that to protect against hazardous reverse polarity situations the main incoming AC breaker on a boat should be of the two-pole type". (Better yet, says he, is a two-pole breaker on each branch circuit UNLESS all onboard circuits are polarized.) Look at ANY- and probably ALL- wiring diagrams and you will see they always show a hot and neutral cutoff. That's not my opinion- that's a statement of fact. How older boats are wired, is, well, old-hat knowledge.

As your source above states "It's been beaten into my head for so many years that you NEVER break the neutral that I have trouble accepting a system that interrupts it." He needs to go back to school and see what these modern times have changed- like doctors who need to keep up with current medical proceedures. Things may have changed since 2003. Calder's 3rd edition is 2005.

I think it asinine to put the RPI AFTER the circuit breaker. You don't know until it's too late you have a reversal, and if the breaker-fed light trips, you never will get the RPI on. With the indicator light BEFORE the breakers, that should tell you to not even turn on the breakers. Common sense again, but no doubt there are those who will do it just to see if anything happens.... I have a short power cord on which it is obvious to see the white and black are reverse mid-cord. My sailing club uses it if anyone wants to test their reverse polarity indicator- if they want to.

As before, Blitz needs a two-pole ganged AC main and a reverse indicator lamp wired on the line side of the breakers. Poor Blitz- he's probably half way through a bottle of some beverage by now.

 

[Stu Jackson]

I'd join in with the beverages, Ron

Opinions: someone once replied your repeated mentioning of this issue that "this is what this forum is all about." I agreed with him then and still do.

What I was trying to do was to share important information. First, to correct a BIG mistake that I'd made [about cutting the neutral] and wanted to clear that up before too many read it and did something wrong, and second, to have documentation that I'd collected about the subject exposed to more people. I went back and changed those posts to add [ed. later by Stu: wrong...]

I also note that Blitz had told us about the wiring in an early one of his posts: "Left to right Top: P3 Green, P2 White, P1 Black
Left to Right bottom: P3 - empty except small wire for reverse polarity light, P2 White, P3 Black." It appears that either the neutral was cut or it was wired with the RP on one of the breakers. We just don't know from here.

The points expressed in my last "Summary" post remains valid: don't cut the neutral, as I'd mistakenly recommended; use a lower trip breaker to pop if reverse polarity is detected on a second breaker if you choose to go this way. Single HOT breakers were fine, years ago, until updated Codes recommended better solutions, which were included in the "Summary" post text.

Other than that, there was a good discussion and description of the varying points of view, upon which I did not take any position.

You finished one paragraph so nicely with: "He needs to go back to school and see what these modern times have changed- like doctors who need to keep up with current medical procedures. Things may have changed since 2003. Calder's 3rd edition is 2005..."

Please help out here, what's new, specifically about breakers? And what's different than suggested in the summary I posted?

I don't have Calder's 3rd edition. But there seems to be an overlap between this paragraph and the RPI discussion that you then moved into.

Where you went into the RPI again, when I'd already agreed with your earlier. Case closed, you're right, I just seem to feel that it works fine, for me, either way, your boat, your choice. If I was rewiring my boat, the way you'd done yours and congratulations for doing such a good job on that because I know how good you feel about it, then I would do it, too.

You concluded: "As before, Blitz needs a two-pole ganged AC main and a reverse indicator lamp wired on the line side of the breakers. Poor Blitz- he's probably half way through a bottle of some beverage by now."

I agree and that's what I would do if it was my boat. And I don't think of him as "Poor Blitz," I think we all learned something.

Thanks a lot for your help on this interesting and important issue. Challenging us all to do our "research" and "homework" and provide links to reputable sources remains important, as always.

 

[Ron20324]

Let's all pop a top and go watch Captain Ron- for those of us who have it, that is. It happened that as I wrote some replies to the thread, others posted their reply with different info. I was not challenging you personally, just catering to the others who may have been tuned in.

 

[Rick Webb]

Any Resolution Yet?

If the Duck Tape won't hold it closed maybe a bungee cord will

 

[Blitz]

As an update, I found and installed the same replacement switch. Works great as a temporary solution. Working on the diagram and rewiring some items to evaluate the AC system as a whole. I wnat to thank all of thise who contributed to this thread - it has been most helpfull and I'm sure I'll need to compose some more questions or search the archives for the other issues that might arise on any rewiring.