Wiring A 3 Pole 12v Switch

[rightsaidfred]

8 minutes ago, Oddfellow said:

There are no regulations that are enforceable other than the BSS which is pretty pants for electrical safety. This is about best practices using the knowledge that we have today and not just doing things as they did 20/50 years ago because it worked then.

If we can justifiably say that, for instance, screw terminal blocks should not be used to terminate cables because we know that it damages them, would it not be better to use terminals that we know are substantially better and ultimately safer?

Of course, anyone can do anything they like on their boat and see whether it passes a BSS next time or causes damage in the first place. As someone who holds a marine electrical installation certificate, I felt it was better to counter some of the advice given here by people who aren't professional in these matters. 

 

Andy I dont disagree with anything you have said and would always go for best practise and normally use proffesional assistance, however there are a number of members who while not working in the boat industry are still proficient and have been around boats far longer than they would probably care to remember and are familiar with most of the anomalies found in many boats.

Fred

[OldBerkshireBoy]

3 hours ago, Oddfellow said:

I would never advocate merging or combining fuse/switch panels. If you already have such a panel, great, but never add one if you already have a fuse panel elsewhere for the same reason it's bad practice to add a fuse hidden away behind, say, a fridge. whilst you have another fuse panel somewhere else - when there's a fault, you have to trace everything and a long-forgotten fuse behind something will make that process hard. Keep all things alike in the same place. All fuse panels together; all main circuit switches together. 

Also, as I said earlier, a fridge needs a decent current and some fuse panels won't have switches capable of the load. One of the best ways to switch such a device is with a relay where you let the relay deal with the heavy load and use a low-amperage switch to energise the relay. 

There are many dos and don't to marine electrics but mostly in terms of safety. Most boat owners have just about enough knowledge to rig something to make it work but with little regard to safety, long-term operation and troubleshooting. It's not dangerous 'cos it's only 12v, right? Have you ever seen cable insulation melt because some tool has put in a big fuse because the right sized one kept blowing? 

 

 

Seen a 13a fuse wrapped in tin foil in a household plug. "Just to last the weekend" he said. 

[Helian]

I used to be in the motor trade and saw many vehicle fuses so encapsulated 😳

43 minutes ago, OldBerkshireBoy said:

Seen a 13a fuse wrapped in tin foil in a household plug. "Just to last the weekend" he said.