This is wrong, right?

[Roger Long]

I was relieved to check the builder's electrical schematic for Strider and not see any tie between the AC neutral and AC ground. Then I looked at the panel.

This is the front:

and this is what's behind:

That sure looks like a tie to me on the three way breaker unless there is something about how it's arranged inside that I don't understand. The shorepower line is the top on with the gray jacket.

Seems to me that I should remove the small white tie wire and move the green tie to the AC ground buss to the upper screw.

Have I got that right?

Update from later posts:

I discovered that this boat doesn't have a tie between the AC and DC ground systems or any evidence that there ever was one although it's shown on the builder's electrical schematic.

I took the two green ground wires off the breaker section with the white tie and it is an open circuit with the switch in either position. Is it possible that a breaker trip (which I can't test at this point) is supposed to make a connection in this section so that ground and neutral will be tied together? If so, do I want to keep this feature and just add the standard tie between the ground systems?

 

[Auspicious]

That sure looks like a tie to me on the three way breaker unless there is something about how it's arranged inside that I don't understand. The shorepower line is the top on with the gray jacket.

Seems to me that I should remove the small white tie wire and move the green tie to the AC ground buss to the upper screw.

I think you're right, unless the ground breaker/switch is normally closed (NC) instead of normally open (NO). If the ground switch operates in the opposite sense then it is correct and an elegant solution to keeping ground and neutral separate plugged in to shore power and connected when on a generator or inverter.

Unplug the boat and use an ohmmeter on all three switches of the main breaker in both positions.

 

[kloudie1]

Yup, I think you are right .. it is wrong.. right.
Looks like the master connects the white to the green when it is on.. It looks like the jumper should go away.. Does the green go to bonding/engine ground? Looks additionally like the white is always jumpered to whatever is hooked to the green switched side of the master switch..

 

[Roger Long]

I just took off the two green wires from the terminal on the opposite side of the jumper and there is no continuity across that block of the breaker in either breaker switch position. I haven't taken anything else apart or done any other diagnostics.

Oh yes, it turns out that there is no tie between the AC and DC ground systems. It's shown on the electrical schematic but it's not on the boat.

 

[Roger Long]

I think I may have figured it out.

If neutral (white wire) is hot as is the case in a reverse polarity situation, current flows to ground through the reverse polarity light.

It also flows through the white jumper wire into the left hand breaker segment which is not connected through to the terminal with the two green ground wires. There must be circuitry inside the breaker to cause it to trip when current is sensed at the terminal the white jumper wire is connected to opposite the green grounds.

There is no continuity between the left segment terminals in either switch position. The 3 LED tester I keep plugged into the outlet next to the panel did not show a missing ground when I had AC plugged in a week ago so I don't think anything is defective in the breaker.

All I'm missing is the tie wire between the AC and DC grounds.

This is right, right? Maine Sail?

 

[woodster]

you may be on to something there Rodger ....i made a statement about a year ago on here about the main breaker haveing also had the ground run through it and as i look at your pic i see the same thing i have on mine...and you also have cleared up some doubt about my main breaker being bad....when i metered it last year i also found the third leg in the same condition and was worried about haveing to replace the main breaker and found out they are about $98.00....wow what a relief.....

regards

woody

 

[Roger Long]

wow what a relief

Don't break out the champaign [FONT=&quot][/FONT]until we hear from someone who knows more about this than I do

 

[kloudie1]

Sounds plausible, Roger.. I'll have to make a point to look at mine next time I am back in the spaghetti..
So you were wrong? Right? (as I was too)

 

[Bill Roosa]

Have you guys ever heard of a three way gang CB?????
You have no doubt seen the two gang for hot and neutral.
And where is the diode for the reverse polarity circuit???
I believe that if Roger measures the "ground" CB he will find that it is not really a switch in the traditional sense. You should never have a switch for the ground wire BTW, NEVER. this setup allows the reverse polarity switch to work by introducing a diode (the CB in this case) into the circuit when you flip the AC on.
So Roger, get out your diode tester and confirm that the ground portion does infact pass current in only one direction when flipped and not at all when turnd off. Should be a fairly high Vf

 

[Bill Roosa]

Roger, does the red reverse polarity light act as a push button switch? I think it just lights up when it detects the reverse polarity, right? then the ground portion of the CB does its thing and interupts the circuit by tripping the breakers.

 

[Ron20324]

Present day wisdom is there should not be a breaker in any ground path. This came up last year because some early (Catalinas ?) boats came with the triple breaker and the owner could not find a new one. It looks like some re-wiring of new breakers is in order, Roger. IIRC the green AC ground should only be connected to the neutral back at the shoreside breaker box- not on the boat?

 

[Bill Roosa]

I believe the use of 3 gang CB is bing discouraged due to cost. Seems the doide and switch that the "ground" CB provided are cheaper as individual items. that is why you can't find them any more and all you can find is the double gang CB.
The whole triple gang was intended to make it goof proof in telling if you had reverse plarity or not. You plug in and the light lights up, period. Shore power will not engage unless it is wired correctly. Now you have the button to press and a light to look at and a lamp test...... What is the world coming to. Next thing you know I'll have to actually start taking responsability for my actions. ;-)

 

[Roger Long]

Roger, does the red reverse polarity light act as a push button switch? I think it just lights up when it detects the reverse polarity, right? then the ground portion of the CB does its thing and interupts the circuit by tripping the breakers.

That's exactly the way it works. It's just a light. I had reverse polarity once but I don't know if the breaker tripped because I turned it right off and went to have a talk with the marina.

Sounds like I have a good system and will be sorry when it goes and I have to replace it with what's available now. I wish I'd known someone removed the tied to the DC ground though. Good thing I haven't spent a lot of time on shore power.

Still, nothing is official on this forum section until we hear from Main Sail. I wonder where he is?

 

[woodster]

those breakers are still available but the are very expensive ($98.00 last time i checked)......i am glad this thread is happening because it has made me see that the breaker is not bad and still serviceable........ thanks to all involved......

regards

woodster

 

[Maine Sail]

Roger,

That certainly is an odd breaker set up by today's standards. It is hard to say from here how that breaker works but I suspect it is fine. I can tell you that the green/ground wire is to not to be "broken" by a breaker and the Hot/Black and white/neutral must be broken by the breaker.

But I suspect that the third section of that breaker does not "break" and the white jumper is only there to alert the reverse polarity light of voltage on the GREEN wire. The green wire goes directly to the ground buss and the white wire is probably there to sense a ground fault reversal.

You want to make sure that there is no continuity between white/neutral and green/ground on-board your vessel but it does not look like there would be. No matter what position the breaker is in there should be no continuity between white and green on the boat and they should only be tied together on-shore. The only time the green is used is as a fail safe.. You can check it at the shore power inlet and at the panel and make sure you have not continuity but I doubt you'll find it.

 

[Johnb]

The way the 3 gang breaker works is that one of the gangs, connected between neutral and ground, causes all three to trip if the voltage between neutral and ground gets over a certain amount, sometimes about 65 volts (AC). This protects against neutral and live being reversed. Neutral and live are both fed through the breaker (hence the other two switches) so that if it trips and neutral and live are reversed live is always interrupted.

 

[Maine Sail]

ABYC E-11 Excerpt:


11.17 APPLICATION OF TYPES OF SHORE POWER CIRCUITS

11.17.1 Single Phase 120-Volt Systems with Shore-Grounded (White) Neutral Conductor and Grounding (Green) Conductor.

11.17.1.1 The shore grounded (white) and ungrounded shore current carrying conductors are connected from the shore power inlet to the boat's AC electrical system through an overcurrent protection device that simultaneously opens both current-carrying conductors. Fuses shall not be used instead of simultaneous trip devices.

11.17.1.2 Neither the shore grounded (white) neutral conductor nor the ungrounded current carrying conductors shall be grounded on the boat.

11.17.1.3 When more than one shore power inlet is used, the shore power neutrals shall not be connected together on the boat. (See E-11.5.5.6.2.)

11.17.1.4 The shore-grounding (green) conductor is connected, without interposing switches or overcurrent protection devices (See E-11.5.5.5.), from the shore power inlet to;

11.17.1.4.1 an optional galvanic isolator, and then to

11.17.1.4.2 all non-current carrying parts of the boat’s AC electrical system, including

11.17.1.4.3 the engine negative terminal or its bus.

11.17.1.5 If an optional galvanic isolator is used, the shell of a metallic shore power inlet shall be electrically insulated from the boat.

11.17.1.6 If the boat's AC electrical system includes branch circuit breakers, the branch circuit breakers shall simultaneously open both current carrying conductors unless a polarity indicating device is provided.




Hope this helps..

 

[Bill Roosa]

The "ground CB" in the gang is not a CB. Also the ground wire goes directly to the ground buss without entering the "CB" so it meets the "no CB on the ground wire rule. It senses current flow from the neutral to to ground when the neutral is incorrectly wired and hot and trips the circuit. It has a fairly high resistance so it does not conduct "current" to the ground wire when the shore power is wired correctly. You have to remember that the neutral is a (current carring) ground and will show no voltage in normal operation. It only shows a voltage when the shore power is wired backward

 

[Ron20324]

If it were my boat, I'd put the incoming green right onto the ground buss. I see the present green is extended to the buss by a wire of smaller size. It's hard to tell for sure, but it looks like the black wire from the breaker to the pos buss may be a reduced size also, but we do not know the amp rating of the breakers. It looks like the white wire to the neu buss is a 14.

I know it's a matter of opinion, but for myself I don't think I would want to the breakers to trip just because of a reversal. A "reverse" light does not necessarily mean a truely "reversed" incoming line. I've had my reverse light come on just because of a dirty connector on the shore power cord. Reversed AC can still be used, though should be checked out and avoided. At least that big red light should come on before even turning on the breakers.

 

[Roger Long]

I've had my reverse light come on just because of a dirty connector on the shore power cord.

True. That happened to me once. Loose screw at the shore power connection.

I like the breaker trip though. I don't use shore power much and it's about the least mission critical thing on the boat. If there is anything suspect about it, I'd just as soon have it click right off until I can check it out.

I carry one of the 3 LED testers plugged into the galley outlet next to the switch panel and an adapter. If I get a reverse polarity situation, I can always hop ashore and plug directly into the dock outlet to determine if my next move should be to the marina office or my toolbox.