An electrical question/ whats this for?

[steve yates]

Im stripping out the electrics and elctronics on my longbow. Ive been carefully labelling wires where possible when removing switch panels etc, but now I’m wondering whatfor? If I am doing a fresh install from start, does it matter about finding out whats what ? I could speed itup a lot by just snipping away and ripping out merrily everywhere I find cables As I dont intend to reuse any cabling. Is there anything I should be careful about and try and keep trackoff? Like the transponder cable, that I won’t be replacing.

Also, so far i have a fair idea of what everything did and was for, until I got to these. Any ideas and are they worth keepimg for possible reuse or just rip out and bin?
pic 1, some kind of shunt or big breaker?


pic 2 and 3, looks like a 240v domestic set up? There are no 3 pin sockets anywhere on the boat and no shorepower fitting that I have seen. I do know that although the boat had a 1,2,both isolator fitted, if that red switch was in the off position, nowt worked.

Pic 4, switch just to the right of the pics above, clearly says ac power only, but no idea why.

 

[Seastoke]

It looks like some nob has used ac board for dc , is there any dc control panel . The thing in pic one looks like a rectifier.
If you trace the 2 wires in pic4 that connect underneath that will tell you what it’s for.

 

[andsarkit]

Can you read what is written on the 2 silver devices on the heatsink?
It looks like a voltage regulator or possibly a diode but I can't see any output wires.

 

[Supertramp]

Even if you are replacing lots or all there is some sense in understanding what was originally installed where. A boat like the Longbow probably had a lot of electrical bits retro fitted from a pretty basic platform. Some of the new bits may be ok, and may even be in a sensible place? Replacing wiring and joints/junctions may not mean relocating items.

My boat's electrics were (are) complicated but had been reasonably thought out. The devil was in the added on items, wired direct to the batteries or spurred off in some hidden recess. I am improving it piecemeal by removing redundant wiring and labelling wires as I discover their function and reassigning switches rather than adding more. Some wiring need replaced. Much of it doesn't and I have no desire to mess with it without good reason.

Pic 2/3 looks like a domestic consumer unit for distributing 240v shore power. The switch for AC next to it does not look suitable for DC currents - replacing units like these is straightforward but pointless unless you need their function.

Choose the locations for switchboards etc well so that they are dry and easy to work on. And give yourself twice as much space as you think you will need. Unless you are electrically competent there is merit in approaching the problem step by step - change one part of the system and check the rest still works.....

Oh, and add a good battery monitor so you know what's happening.

 

[doug748]

Picture one looks very much like the shunt regulator from LVM, supplied as an option on their Aerogen wind generators. I have one on board.

The red and black wire connect to the battery and it senses any overcharge and dumps it to the tin cans in the middle - "power transistors" I cant read the figures but (working from old notes don't take this as gospel) I think they mine say: MJ2955 T8706. The part no was: 94-972-79 and may be on the unit somewhere. I found mine worked ok when I changed to a small solar panel so I kept it.

Now and again people ask for them so you could probably sell it. If you test it, it should start to kick in when a battery reaches 13.8v ish and the pots will start to feel warm to the touch. Take care with installation, the body of the unit is negative when connected - I think you will find it has insulating feet.

.

 

[Stemar]

Don't pull wires out willy-nilly. You may need to use them to pull the new wiring through awkward bits. Do bin that domestic fuse box, though. Completely the wrong thing. Either use circuit breaker switches or blade fuse boxes. You can get them with an LED that lights if a fuse blows or is missing.

One final thought - LABEL EVERYTHING! Sure you know what it all does now but, in five years time when you need to change something, you'll have forgotten.

 

[steve yates]

Thanks folks. I’ll hang onto the shunt and bin the domestic fuse box.
i have a labeller from doing the wee boat, though im going to move the positions of the switch panels and prob batterries, and I think Imay end up rerouting cabling too, to make it easier to access.

 

[LittleSister]

I think you're all wrong, and that it's a conceptual art installation! ?

 

[Tranona]

Thanks folks. I’ll hang onto the shunt and bin the domestic fuse box.
i have a labeller from doing the wee boat, though im going to move the positions of the switch panels and prob batterries, and I think Imay end up rerouting cabling too, to make it easier to access.

The approach I took was to identify any item I intended to keep such as lighting (at least the location) and trace the power supply back to its source so that the end can be labeled. In most cases either the wiring could be kept and just connected to the new switch panel. For example the lighting circuits went to an existing switch panel and as I retained all the wiring I just extended the cabling to the new panel in the new location. Everything else I binned. All new equipment was cabled from scratch. Batteries, cabling, bus bars, switch cluster for charging management, battery monitor, mains charger,B2B for bow battery are all new. Shorepower added and properly installed (previously just an input leading to one socket!).

Photos give an idea of before and after. Do not underestimate the amount of time required to do it properly, nor the amount of thinking time to work out the best way(for you) of doing it. As discussed here many times there is no single right way of wiring, not single choice of components to use. I bought most of my bits from 12volt planet and the ready wired distribution panel from Axon. Note the batteries re only tempotatily wired up in this shot.

 

[steve yates]

I’m identifying the wiring for the engine controls & windlass etc, as the engine was a relatively new install. Everything else I am going to bin and start from scratch, as I intend to move the positions of where the batteries and switch panels were, and change the routing of the cabling. None of the old cabling seems to be tinned, and there is a lot of what looks like domestic twincore with blue and brown wires, and I am finding stuff like this! I’m surprised she never went up in flames So I reckon that whatever I do is going to be a lot better than what I had.

 

[Tranona]

Looks horribly familiar - although when the surveyor checked all the kit everything worked - but in his own words "don't know how or why"

Engine is easy as it only needs power from the start battery and a means of directing charge to the house bank (splitter, VSR etc) Windlass a bit more complicate depending on how you are powering it.

 

[apogee]

Im stripping out the electrics and elctronics on my longbow. Ive been carefully labelling wires where possible when removing switch panels etc, but now I’m wondering whatfor? If I am doing a fresh install from start, does it matter about finding out whats what ? I could speed itup a lot by just snipping away and ripping out merrily everywhere I find cables As I dont intend to reuse any cabling. Is there anything I should be careful about and try and keep trackoff? Like the transponder cable, that I won’t be replacing.

Also, so far i have a fair idea of what everything did and was for, until I got to these. Any ideas and are they worth keepimg for possible reuse or just rip out and bin?
pic 1, some kind of shunt or big breaker?
View attachment 145595

pic 2 and 3, looks like a 240v domestic set up? There are no 3 pin sockets anywhere on the boat and no shorepower fitting that I have seen. I do know that although the boat had a 1,2,both isolator fitted, if that red switch was in the off position, nowt worked.
View attachment 145596View attachment 145597
Pic 4, switch just to the right of the pics above, clearly says ac power only, but no idea why.
View attachment 145599

1 looks like the shunt regulator I had from Marlec, back in the day.

 

[penfold]

Looks horribly familiar - although when the surveyor checked all the kit everything worked - but in his own words "don't know how or why"

Engine is easy as it only needs power from the start battery and a means of directing charge to the house bank (splitter, VSR etc) Windlass a bit more complicate depending on how you are powering it.

Some of the electrics on the old man's boat are like that; bits of straggly wire dangling in open space, strung between verdigris-covered chocolate block and nothing labelled. Most of it works, although it's a mystery to confound Ohm himself why.