Double or triple tapping 110 breakers?

[Sailorman Ed]

I know in houses, if you double tap a breaker, you fail inspection but what about on boats? I am replacing a Blue Seas 110 breaker panel and some breakers were double and even triple tapped. I am sure this was done at the factory. What is the correct way to connect several wires to one breaker? If it were a house, i would wire nut them in a larger box but no wire nuts on the boat for me.



Also, what is the best way to clean a slightly corroded tin plated bus bar?

[SailingHarmonie]

Originally Posted by Sailorman Ed

I know in houses, if you double tap a breaker, you fail inspection but what about on boats? I am replacing a Blue Seas 110 breaker panel and some breakers were double and even triple tapped. I am sure this was done at the factory. What is the correct way to connect several wires to one breaker? If it were a house, i would wire nut them in a larger box but no wire nuts on the boat for me.



Also, what is the best way to clean a slightly corroded tin plated bus bar?

For corroded bus bars, replace. Once the plating is compromised, there is no going back. If they are corroded, they are likely getting wet with salt water. Fix that too.

Definitely no wire nuts! There are household breakers with terminals specifically designed to double tap, but of course that does not guarantee your inspector will approve...

My memory is that the ABYC limits the number of connections on a single terminal to five. I believe that applies to both AC and DC. On any installation I do, I never do more than two power connections under one screw or nut. Sometimes--like on battery terminals--I will have a third measurement connection for voltage or temperature on top.

For entertainment, I have attached before and after photos. Before as the factory in France wired the 220V AC panel, and after I fixed it...

[s/v Jedi]

Originally Posted by Sailorman Ed

I know in houses, if you double tap a breaker, you fail inspection but what about on boats? I am replacing a Blue Seas 110 breaker panel and some breakers were double and even triple tapped. I am sure this was done at the factory. What is the correct way to connect several wires to one breaker? If it were a house, i would wire nut them in a larger box but no wire nuts on the boat for me.



Also, what is the best way to clean a slightly corroded tin plated bus bar?

I wire my breakers to terminal strips (DIN rail or US style)

Assuming it’s copper under the tin: use a maroon scotchpad to clean it up, then brush on liquid tin: https://www.amazon.com/MG-Chemicals-.../dp/B081KRTZ4S

[Sailorman Ed]

Jedi, I have seen pics of your wiring, very nice. I actually had liguid Tin in my Amazon shopping cart. I'll get a scotchbirte pad.
'
Harmonie - I am surprised that you could add multiple connectors but thanks.
Ed

[JBP]

In house wiring, a "double tap" usually means two circuits on one breaker which is bad. In boats having two circuits on one breaker is still bad, for example cabin lights plus nav instruments on one breaker. However that does not mean you can't have two wires on one breaker, for example a cabin light wire running forward and a cabin light wire running aft is essentially one cabin lights circuit.
To avoid connecting too many wires to one screw, a terminal block is usually used for positive wires. A bus bar can be used to declutter negative wires.

[Cpt Mark]

As a former home inspector. The reason double tapping is bad is that you cannot get the screw down tight enough to make a perfect connection which leads to microscopic arcing and if left long enough could lead to fire. Any competent inspector should see if they are double tap designed and if so, give it a pass.

I've not waded through the ABYC guidelines but I would suspect that double tapping is a no no. And, it's found on virtually every used boat out there.

[rslifkin]

Originally Posted by Cpt Mark

As a former home inspector. The reason double tapping is bad is that you cannot get the screw down tight enough to make a perfect connection which leads to microscopic arcing and if left long enough could lead to fire. Any competent inspector should see if they are double tap designed and if so, give it a pass.

I've not waded through the ABYC guidelines but I would suspect that double tapping is a no no. And, it's found on virtually every used boat out there.

As long as there is adequate screw length, that shouldn't be an issue with properly sized and aligned ring terminals (as used on a boat), right? Home breakers are often designed to accept a bare wire connection which is a different story.

[Cpt Mark]

Originally Posted by rslifkin

As long as there is adequate screw length, that shouldn't be an issue with properly sized and aligned ring terminals (as used on a boat), right? Home breakers are often designed to accept a bare wire connection which is a different story.

In theory that makes sense. But, again, I haven't looked at the ABYC.

A very long time ago there was a company called Zinser who manufactured breaker panels for homes. They are long out of business but their panels are still found and need replacing. When they manufactured them the breakers slid in and locked as they should. However, there was the tiniest of gaps in there that lead to arcing which ate away the metal creating bigger arcing etc. It was many years before the houses caught fire because of this. I've only seen 1 of these panels but I could hear from a long way away.

[Turtle Blues]

Breakers are intentionally supplied with short screws to prevent this. If someone triple tapped one hopefully they replaced the screw which I do not recommend.
The accepted installation would be a single wire to a terminal strip with proper jumpers installed to power the additional circuits.

[FlyingScot]

ABYC has a 4 terminals per terminal stud, with highest ampacity at the bottom working your way from largest to smallest.

There is also a rule that an AC motor has to have it's own individual over current or thermal protection device.

I can't find anything else, but that doesn't mean there isn't any.

[Sailorman Ed]

Assuming it’s copper under the tin: use a maroon scotchpad to clean it up, then brush on liquid tin: https://www.amazon.com/MG-Chemicals-.../dp/B081KRTZ4S

So I followed Jedi's suggestion, used the maroon scotchpad, then the salt and vinegar cleaner, then the Liquid Tin. Not perfect but substantially better. I also treated an old bare copper bussbar that was in remarkably good condition and it cleaned up very well with the salt vinegar solution and the tin looks the best here. I couldn't immerse the small double one so I tried just covered with a paper towel but the results were not good.


Tomorrow I am going to try the same process on the ends of wires.

[boatpoker]

Originally Posted by Sailorman Ed

I know in houses, if you double tap a breaker, you fail inspection but what about on boats? I am replacing a Blue Seas 110 breaker panel and some breakers were double and even triple tapped. I am sure this was done at the factory. What is the correct way to connect several wires to one breaker? If it were a house, i would wire nut them in a larger box but no wire nuts on the boat for me.



Also, what is the best way to clean a slightly corroded tin plated bus bar?

A few statements here about what people think ABYC might say ... I'm not getting into that argument so PM me an email address and I'll send you a copy of the Standards and you can see for yourself what the they actually say, which is quite different.

[s/v Jedi]

Originally Posted by Sailorman Ed

So I followed Jedi's suggestion, used the maroon scotchpad, then the salt and vinegar cleaner, then the Liquid Tin. Not perfect but substantially better. I also treated an old bare copper bussbar that was in remarkably good condition and it cleaned up very well with the salt vinegar solution and the tin looks the best here. I couldn't immerse the small double one so I tried just covered with a paper towel but the results were not good.

Tomorrow I am going to try the same process on the ends of wires.

Yours were pretty bad the black stuff is zinc oxide, to get rid of all that you may be better off sanding it to bare copper.

You can also brush it on with a small brush or even Q-tip. It’s nice stuff, right?

[sinnerman]

Originally Posted by SailingHarmonie

For corroded bus bars, replace. Once the plating is compromised, there is no going back. If they are corroded, they are likely getting wet with salt water. Fix that too.

Definitely no wire nuts! There are household breakers with terminals specifically designed to double tap, but of course that does not guarantee your inspector will approve...

My memory is that the ABYC limits the number of connections on a single terminal to five. I believe that applies to both AC and DC. On any installation I do, I never do more than two power connections under one screw or nut. Sometimes--like on battery terminals--I will have a third measurement connection for voltage or temperature on top.

For entertainment, I have attached before and after photos. Before as the factory in France wired the 220V AC panel, and after I fixed it...

Looks like they got aa "deal" on brown wire...

[stormalong]

Originally Posted by sinnerman

Looks like they got aa "deal" on brown wire...

Brown is the European equivalent of black for AC wiring in the USA.

Once all the wiring is done a coat of Boeshield will prevent corrosion. BUT do it after all the terminals are in place and tight. You don't want the Boesheild under the terminals.