8AWG On-Off-On switch needed

[janice142]

Greetings Gents. A few slips down from me is a lovely boat. She's been experiencing problems with one leg of her AC power. We have isolated the problem to this switch:





As you can see there are a boatload of 8 gauge wires into that beast.



The thing is, IDEALLY it would be great to buy another On-Off-On switch that would fit all those wires. The article (next link) explains how we got to this point. Is there another solution? What would you do?

Article here: 8awg Selector Switch Needed article on janice142


If you are curious, here is how we (other fellows and yours truly on the docks) got to this point: (this is a lot... and most of you probably know all this stuff -- and are smarter than I was!)
Part 1: 50 Amp 125/250 Volt Power Plug Wiring How-To (4 wires) article on janice142
Part 2: Troubleshooting a 50A Power Leg Problem article on janice142
Part 3: 50A Power Cord Option to Save Money article on janice142

[twistedtree]

I think yo need something like this


https://www.bluesea.com/products/901...ns_120V_AC_65A


Just check physical dimensions to be sure it will fit.

[High Wire]

It looks like a Shore-Off-Gen transfer switch. The AC hot and neutral are switched (2 poles) The ground is not. Blue Sea makes them but the cutout hole may be different.

[janice142]

Thanks gentlemen... the one TwistedTree posted I happen to have in ships stores. Two actually though one is I believe not correct. Here's what I have:



and the fronts:


The smaller switch (3-1-Off-2-4) feels too light weight. I suspect the larger one might work -- if it will fit.

This vessel has a lot of inputs (starboard side has a 50A125V inlet plus a 30A125V inlet. Port side has a 50A 125V inlet, plus a 30A 125V inlet and the 50A 125/250V 4-wires inlet.


Even though that second inlet says 50A 125/250V it only has three wires, thus just 125V goes down to the switches.

Part of the problem while troubleshooting this mess is that none of us here on the docks read the gosh darn Power Connection page...


From that page I can see there are a boat load of 8AWG wires to those two switches. Starboard contributes one set of wires to each switch.

Port side provides two lines to each switch...

So whatever the owner buys has to accommodate a total of nine 8 gauge wires incoming, plus the ones that feed down to the two distribution panels. My dinky switch definitely cannot handle this many wires safely...

The larger one I picked up for Seaweed (yet another project -- first though the Hatteras needs to get that 32V battery charger powered. That requires the house distribution panel to receive power. We do have power at the back of that second switch as per my multimeter.

And thank you so much. I am learning...

[luna]

Your existing switches are made by Kraus & Naimer. They are a large cam switch manufacturer. You could try a call or email to see if they can direct you to a switch repair service or a stocking dealer in your area. Their contact info follows.

https://www.krausnaimer.com/au_en/contact

What would I do?

If I was convinced that this switch is the cause of the issue I would safely remove the switch and disassemble it. What have I got to lose? It likely comes apart fairly easily once I've figured out the catches.

Once apart I can see if the contacts are damaged beyond repair (pitted) or just tarnished. If tarnished a bit of silver polish on a Q tip mounted in a slow speed drill motor should clean it up. It will be tedious work, but the price is right.
I would not use an abrasive paper unless I have some 2000 grit and can lightly buff the contacts, shoeshine style.

Clean it all well with some acetone and a clean artist paint brush and then I would carefully reassemble.

Now that I understand how the switch works I would check for continuity only on the terminals that should be connected. This of course is switch position dependant.

Once I was convinced it was operating properly and exactly like it's known working brother mounted in the same area, I would install and wire it back up and use it for another 20 years.

Otherwise I would buy a new switch that can accommodate whatever wiring is needed and that does the appropriate switching. Likely $300.00

In the meantime I'd undoubtably power the house breaker panel from the AC breaker panel so the old girl could get her batteries charged, have a cold one and take a bath. Looks like about a couple of feet of 10 ga. and a few ring terminals is all that is required.

[twistedtree]

Are there other switched that are used to select which shore power cords to use?


I ask because looking at the pictures from before I concluded/presumed a few things about how your boat is wired, and those assumptions might not be correct. It can be really dangerous working on stuff like this if you don't confidently know what you are working with, looking at, and understand how it works.


Any chance of a wiring diagram? At a minimum you will need to know what the wires are connected to the suspect switch, how that switch's contacts work, and how the contacts on the replacement switch work.

[mvweebles]

Originally Posted by twistedtree

Any chance of a wiring diagram? At a minimum you will need to know what the wires are connected to the suspect switch, how that switch's contacts work, and how the contacts on the replacement switch work.

Amen. You can really do some damage here. Unless you do a like-for-like swap, these wires need to be traced and identified.

Barrel/rotary switches come in a dizzying array of terminals and on/off permutations. Finding a replacement OEM would be great (or repairing the one you have). Failing that, I'd encourage spending the extra money with a Blue Sea switch. Market is flooded with cheap Chinese knock-offs. This is no place to save a hundred bucks.

Assuming OP gets the circuitry sorted, a suggestion to manage bulkiness of nine heavy wires is to use a back-plane of some sort. Panel builders often terminate the load side on terminal blocks arranged and labeled to mirror the circuit protection/switching panel. This allows for more manageable lengths of wire, possible down-sized for the relatively short run between the terminal blocks and the switch. Also allows for easier labeling of the wire terminals.

Good luck.

Peter

[twistedtree]

The larger switch that you have is a possible replacement. You can see the 63A rating on the label, and that's what matters. Don't worry about the 8 ga wire, or how many wires. That's largely immaterial. What matters is the rating for the switch (63A in this case), the pole configuration (double throw, center off), and the number of poles (2).


The switch you have is 4 pole and you only need 2. But you could use it and leave 2 poles unwired. I can't tell if it's double throw, center off or not. That's the 1-Off-2 position thing.


The specific switch I linked above looks to be the correct 1-Off-2 switch, 2 poles - just what you need.


Also re testing, I think you said in your blog that you did this, but just to confim....


With a meter, you should be able to read incoming voltage on the shore and gen terminals on the switch, depending on which power source is active. Test both. But the output terminal (the one that leads to the panel main breaker) shows no power in any switch position? Is that all correct? That's the way to conclusively identify the switch as the problem.


Any chance of getting pictures of the full label on the candidate replacement switch?

[psneeld]

I wouldn't dare try to diagnose this over the net.

Without understanding where all the wires truly go, I can't even guess what the wiring is really like.

I get the instruction sheet's intentions, but how it is actually wired is a crap shoot.

I too would start with removing the bad switch (if it truly is) and seeing what is wrong with it. I disassembled a few of those types and while a PIA to put back together...not too bad. Just label the wires well.

If the switch still doesn't work, I would chase every wire from both port and starboard receptacles and see where they lead to behind the panels (are there breakers between the inlets and the switches?). I would then label each one...then figure out how each panel to each inlet/set of inlets is wired or should be wired by starting from scratch. I don't mean pull all new wires (although I believe the 50A wires if protected by 50A CBs need to be 6ga.)...you may be able to use the existing wires, just attached to different switches or in different combos.

[mvweebles]

Originally Posted by twistedtree

The larger switch that you have is a possible replacement. You can see the 63A rating on the label, and that's what matters. Don't worry about the 8 ga wire, or how many wires. That's largely immaterial. What matters is the rating for the switch (63A in this case), the pole configuration (double throw, center off), and the number of poles (2).


The switch you have is 4 pole and you only need 2. But you could use it and leave 2 poles unwired. I can't tell if it's double throw, center off or not. That's the 1-Off-2 position thing.


The specific switch I linked above looks to be the correct 1-Off-2 switch, 2 poles - just what you need.


Also re testing, I think you said in your blog that you did this, but just to confim....


With a meter, you should be able to read incoming voltage on the shore and gen terminals on the switch, depending on which power source is active. Test both. But the output terminal (the one that leads to the panel main breaker) shows no power in any switch position? Is that all correct? That's the way to conclusively identify the switch as the problem.


Any chance of getting pictures of the full label on the candidate replacement switch?

The larger of the two replacement switches appears to have a rating of 80 amps. Picture is a bit fuzzy so not sure.

Looking at the OP pictures, there are two switches with some conductors between them. The OP states a desire to combine the two into a single switch which may be possible, but would probably be some sort of 1-2-3-OFF switch. Without a wiring diagram, really hard to tell. Well above my pay grade in electrics which is an Achilles Heel for me.

Reminds me of the classic bomb diffusing scene such as this one in MASH

https://youtu.be/UcaWQZlPXgQ?si=ntf770X4MEt67Ld4

Peter

[twistedtree]

Originally Posted by mvweebles

The larger of the two replacement switches appears to have a rating of 80 amps. Picture is a bit fuzzy so not sure.

Yes, sort of. If only it were that easy. I'm not very brushed up on it, but I think the 80A rating is the max load that it can disconnect without welding the contacts. You can also see there is an AC1, AC2, and AC3 rating. These are for different types of loads, and the switch has different amperage ratings for each. I'm pretty sure AC1 is the rating to use, and think it reads 65 or 63A. There also is a "C" rating of C63 (again, from memory since I can't look at the picture and reply at the same time). I think that's the AC1 rating, and "C" indicates that it's a C trip curve which is the time/overload sensitivity of the breaker. This has been new to me over the past few years, and as I said I'm not very brushed up on it.


Looking more closely at the new 4-pole switch, I think I see something like C48 which might mean it's not rated high enough. That's part of why I'd like to see the entire sticker.


Probably way more than you ever wanted to know.....

[Bacchus]

Originally Posted by twistedtree

Yes, sort of. If only it were that easy. I'm not very brushed up on it, but I think the 80A rating is the max load that it can disconnect without welding the contacts. You can also see there is an AC1, AC2, and AC3 rating. These are for different types of loads, and the switch has different amperage ratings for each. I'm pretty sure AC1 is the rating to use, and think it reads 65 or 63A. There also is a "C" rating of C63 (again, from memory since I can't look at the picture and reply at the same time). I think that's the AC1 rating, and "C" indicates that it's a C trip curve which is the time/overload sensitivity of the breaker. This has been new to me over the past few years, and as I said I'm not very brushed up on it.


Looking more closely at the new 4-pole switch, I think I see something like C48 which might mean it's not rated high enough. That's part of why I'd like to see the entire sticker.


Probably way more than you ever wanted to know.....

I've stayed on the sidelines here as I'm no expert with codes & practices but read the comments on ratings frequently. It seems the (IMO) important point that hasn't been clearly stated is that (unless I missed something along the way) these switches control the sources for two panels shown and both panels are protected at 30A level. The fact that 50A plugs / inlets were chosen for 30A application is a point of confusion. I have read many posts here on TF citing the superiority of 50A twist locks vs 30A twist locks. I don't believe there is any code prohibition against using a higher rated device for a lower A load so long as the wiring is capable of handling the A load that the protection (breaker) provides.

My conclusion is that the switch wiring is more than adequate for 30A loads and the switches are more than capable of handling those loads.

Citing a lower A capability of one Sw vs another as a deficiency seems irrelevant unless you consider higher and higher A capacity as a ( unnecessary but) worthwhile cost / benefit trade- off.

[twistedtree]

Originally Posted by Bacchus

I've stayed on the sidelines here as I'm no expert with codes & practices but read the comments on ratings frequently. It seems the (IMO) important point that hasn't been clearly stated is that (unless I missed something along the way) these switches control the sources for two panels shown and both panels are protected at 30A level. The fact that 50A plugs / inlets were chosen for 30A application is a point of confusion. I have read many posts here on TF citing the superiority of 50A twist locks vs 30A twist locks. I don't believe there is any code prohibition against using a higher rated device for a lower A load so long as the wiring is capable of handling the A load that the protection (breaker) provides.

My conclusion is that the switch wiring is more than adequate for 30A loads and the switches are more than capable of handling those loads.

Citing a lower A capability of one Sw vs another as a deficiency seems irrelevant unless you consider higher and higher A capacity as a ( unnecessary but) worthwhile cost / benefit trade- off.

It's tough to say without understanding what other breakers are in place between the inlet and the switches and breakers that we see. But in general, if you have a 50A inlet breaker, then everything down stream of it needs to be able to handle 50A. I'd have to check whether 8 ga is OK for 50A. I'm used to seeing 6 ga. After the 30A panel breakers, then everything needs to be able to handle 30A.


Unless there is a 30A breaker upstream of the switches, then they need to be rated for 50A or more. 63A is a typical increment for European-made products.

[mvweebles]

Originally Posted by twistedtree

......I'd have to check whether 8 ga is OK for 50A. I'm used to seeing 6 ga..

Doesn't look like 8 AWG is rated for 50a even for short distances. Good catch.

http://assets.bluesea.com/files/reso...on_chartlg.jpg

Peter

[twistedtree]

Originally Posted by mvweebles

Doesn't look like 8 AWG is rated for 50a even for short distances. Good catch.

http://assets.bluesea.com/files/reso...on_chartlg.jpg

Peter

I've never looked at this closely, but attached is what ABYC says. The allowed current depends on the insulation temp rating, whether the wire runs through an engine space, and whether the conductors are individual or bundle in various ways. 8 GA is probably OK in this case, but it's all about the installation details and and wire specifics.

[mvweebles]

Originally Posted by twistedtree

I've never looked at this closely, but attached is what ABYC says. The allowed current depends on the insulation temp rating, whether the wire runs through an engine space, and whether the conductors are individual or bundle in various ways. 8 GA is probably OK in this case, but it's all about the installation details and and wire specifics.

I don't understand the charts -

1. There is no reference to circuit distance or voltage drop.
2. At 60C, the conductors are not permitted in an engine space but all other temperatures are permissable. Why?

Peter

[psneeld]

Originally Posted by mvweebles

I don't understand the charts -

1. There is no reference to circuit distance or voltage drop.
2. At 60C, the conductors are not permitted in an engine space but all other temperatures are permissable. Why?

Peter

That amps number is max ampacity....the maximum without regard to voltage drop and not becoming a hazard due to heat.

The 60C is the rating of the insulation.

[Bacchus]

Originally Posted by twistedtree

It's tough to say without understanding what other breakers are in place between the inlet and the switches and breakers that we see. But in general, if you have a 50A inlet breaker, then everything down stream of it needs to be able to handle 50A. I'd have to check whether 8 ga is OK for 50A. I'm used to seeing 6 ga. After the 30A panel breakers, then everything needs to be able to handle 30A.


Unless there is a 30A breaker upstream of the switches, then they need to be rated for 50A or more. 63A is a typical increment for European-made products.

I understand and appreciate that not knowing details results in lots of speculation. I'm also familiar w/ ABYC requirement to provide cir uit protection with 8 or 10 Ft from the inlet. This boat may or may not violate that provision regardless of panel main breaker size?

I'm thinking of a situation I lived with for many years on a previous boat & marina before a rebuild.
Supply outlets were all 50A 125V and most of us with 30A boats used a Marinco 50A125V to 30A 125V adapter and 30A cord to supply our 30A boats that were protected with a 30A main breaker.
30A cords are usually 10Ga 3 wire. Are the marinco 50A to 30A adapters a code violation? And not legal to use? How can they sell them when by definition they are made to connect a 50A source (outlet or cord) to a 30A cord or boat inlet?

[janice142]

It is dizzying, isn't it?!? We have struggled for certain.

Regarding wires... there are buss bars upstream of the switches: (tomorrow I'll get in there and take a better picture) As I recall there are two more buss bars just to the right of what are in this photo.



The full AC panel is here (below this are the 12v and 32v panels)


Each day it seems to bring more understanding of this power system. 12volts is so much easier -- at least with 50-plus years it seems easier. Sometimes! I do finally "get" the 125/250V part of the power system on the Hatt. Tomorrow is a doctor visit so Thursday I will get back aboard her with my Fox and Hound (the chaser thing) to verify where the power lines start and end.

It was asked... yes, the multimeter does show 125V at the second switch on both Generator and shore power. So power get there -- it stops at that point. It reads the full 125V -- both switches have the exact same voltage.

I believe with help, and lots of notes/taping the wires/labeling/ I can swap out the switches to verify. I will have to bring my step so I can more easily work. I'll also get an extension cord so there will be a fan and light. Tonight I did try to get a full picture of the entire power distribution panel -- it came out too dark. (No lights in the engine room -- at least not yet)

This is the back of the panels (Air Conditioner distribution panel on top, House at the bottom)


I do so much appreciate the advice/suggestions. The fellows on the docks and I have been struggling. Mistakes were made during the learning process. Nothing drastic -- time wasted versus doing something stupid! This has been a learning experience for certain.

Once again, thank you.

[twistedtree]

Originally Posted by psneeld

That amps number is max ampacity....the maximum without regard to voltage drop and not becoming a hazard due to heat.

The 60C is the rating of the insulation.

Exactly