Tidy up/improve my electrics

[robtheplod]

Thanks Tracy & Alan

 

I'm a little paranoid about getting cheap duff cable, but maybe have swung too far the other way!  Great suggestions and will look into for sure. The only other on my list was this one 95mm² (500 Amp) Hi-Flex Battery Cable (Made in EC) | SplitCharge.co.uk

[Sea Dog]

3 hours ago, Chewbacka said:

I think the main reason for direct connection for Webasto units is if it is ‘burning’ and you turn off the power the pump stops and the water in the boiler can boil, also when the Webasto shuts down it goes through a shut down sequence which again would not happen if the power were just switched off, so safer to direct connect to reduced ‘accidents’

Interesting. It makes sense, so it could very well be that. Both seem reasonable reasons to direct connect though, so cover one and you cover both I'd suggest.

 

[Sea Dog]

3 hours ago, robtheplod said:

Thanks Alan, so, going on this if I wanted a 3kw invertor in the future, 95mm is the way to go?   This is great as this all allows me to build in 'what ifs' to this change....

Mine is done in 70mm². You might find this a good compromise if length does not dictate otherwise. It's quite a bit easier to handle than 90mm².

[robtheplod]

I've got a .5m sample of this cable which looks fine. It's quite flexible and has a CE mark on.  Is HI-FLEX cable known as quality cable suitable for use in a narrowboat engine compartment?

 

95mm2 500 A Amps Flexible PVC Battery Welding Cable Black Red 1 - 100M M Lengths | eBay

 

[Alan de Enfield]

9 minutes ago, robtheplod said:

I've got a .5m sample of this cable which looks fine. It's quite flexible and has a CE mark on.  Is HI-FLEX cable known as quality cable suitable for use in a narrowboat engine compartment?

 

95mm2 500 A Amps Flexible PVC Battery Welding Cable Black Red 1 - 100M M Lengths | eBay

 

 

Absolutely no problem.

(Unless : Direct burial installation or outdoors in wet environments as well as contact with hot parts is not allowed.)

 

This cable is sold by one of the top Specialist Cable wholesalers, (my 'Best man' is the Branch Manager) Batt Electrical.

 

 

[robtheplod]

59 minutes ago, Alan de Enfield said:

 

Absolutely no problem.

(Unless : Direct burial installation or outdoors in wet environments as well as contact with hot parts is not allowed.)

 

This cable is sold by one of the top Specialist Cable wholesalers, (my 'Best man' is the Branch Manager) Batt Electrical.

 

 

Thanks Alan. I have some cables which connect between the batteries and the alternator/engine ground. These wont need to be 95mm but will encounter heat, so presume these will need to be of a higher spec?

[Alan de Enfield]

1 minute ago, robtheplod said:

Thanks Alan. I have some cables which connect between the batteries and the alternator/engine ground. These wont need to be 95mm but will encounter heat, so presume these will need to be of a higher spec?

 

I doubt it.

By 'heat' they mean above about 85C which unless in direct contact with the exhaust manifold is unlikely to happen.

The cable is rated at 70C  which is the conductor temperature, the Insulation will be fine up to ~85C

[jonathanA]

You can always sleeve those cables with some convoluted/corrugated cable tube/conduit, which will also provide mechanical protection and look neat 

[robtheplod]

So, just looking at which circuits should be which side of the isolator switch (leisure circuit). We've established that Solar can and should be on the live side at all times. Whats the consensus on the feed from the alternator?  I would assume this always should be live so you dont kill it if the isolator is switched off whilst the engine is running but I'm not sure?

Edited July 2, 2021 by robtheplod

[ditchcrawler]

39 minutes ago, robtheplod said:

So, just looking at which circuits should be which side of the isolator switch (leisure circuit). We've established that Solar can and should be on the live side at all times. Whats the consensus on the feed from the alternator?  I would assume this always should be live so you dont kill it if the isolator is switched off whilst the engine is running but I'm not sure?

I have mine on the load side so when the isolator is off a maximum of bit are dead and isolated including the Alternator and the cable running to it

 

[Tony Brooks]

41 minutes ago, robtheplod said:

So, just looking at which circuits should be which side of the isolator switch (leisure circuit). We've established that Solar can and should be on the live side at all times. Whats the consensus on the feed from the alternator?  I would assume this always should be live so you dont kill it if the isolator is switched off whilst the engine is running but I'm not sure?

 

Ah, I think the BSS has a different interpretation on what is the safest than many of us here.

[robtheplod]

6 minutes ago, Tony Brooks said:

 

Ah, I think the BSS has a different interpretation on what is the safest than many of us here.

ah ok so take it it should be isolated from the batteries when the switch is off.........

[Tony Brooks]

16 minutes ago, robtheplod said:

ah ok so take it it should be isolated from the batteries when the switch is off.........

 

That is as I understand it but it seems many BSS examiners do not check so I would connect it to the battery side but with a lead that is long enough to put on the other side if  the BSS examiner notices. You have to understand that if the cable shorted you would have a cable fire so make sure it is well installed and well protected. The fewer connections on the charging circuit the better.

[robtheplod]

Just now, Tony Brooks said:

 

That is as I understand it but it seems many BSS examiners do not check so I would connect it to the battery side but with a lead that is long enough to put on the other side if  the BSS examiner notices. You have to understand that if the cable shorted you would have a cable fire so make sure it is well installed and well protected. The fewer connections on the charging circuit the better.

Thanks Tony. Currently the Alternator goes direct to a battery terminal (with no fuse etc) so its obviously not been picked up in all these years so far......

[ditchcrawler]

3 minutes ago, robtheplod said:

Thanks Tony. Currently the Alternator goes direct to a battery terminal (with no fuse etc) so its obviously not been picked up in all these years so far......

Its the most unprotected thing on most boats. If I am daft enough to switch off the isolator with the engine running its my fault.

[GUMPY]

Because of the layout, the alternator is just under the floor from the solar controller,  my solar output  goes to the back of the alternator and then direct  to the batteries. Its a marine alternator so has two cables to the batteries. Obviously connected to the battery side of the switch as any charger is allowed to be, an alternator is a charger isnt it? The starter alternator is connected to the starter side of the isolator, just for clarity there are two master switches next to each other.

[robtheplod]

In with the design on my tided electrics I may need to use busbars and also may want to use copper strips to connect equipment up on the board rather than a very short cable run. I've seen others do this and just wanted to check the state of BSS with this. I'd obviously cover as much as possible - heat shrink on a copper strip for example, but this wont be 100%. I've checked BSS and it seems to just imply if a bit of equipment is designed for a cover it should have one, but does this apply to 'home made' bits?

[Tracy D'arth]

2 hours ago, robtheplod said:

In with the design on my tided electrics I may need to use busbars and also may want to use copper strips to connect equipment up on the board rather than a very short cable run. I've seen others do this and just wanted to check the state of BSS with this. I'd obviously cover as much as possible - heat shrink on a copper strip for example, but this wont be 100%. I've checked BSS and it seems to just imply if a bit of equipment is designed for a cover it should have one, but does this apply to 'home made' bits?

All my busbars are in a wooden box with a screwed on front along with the isolators, relays etc, always passes BSS.

[nicknorman]

2 hours ago, robtheplod said:

In with the design on my tided electrics I may need to use busbars and also may want to use copper strips to connect equipment up on the board rather than a very short cable run. I've seen others do this and just wanted to check the state of BSS with this. I'd obviously cover as much as possible - heat shrink on a copper strip for example, but this wont be 100%. I've checked BSS and it seems to just imply if a bit of equipment is designed for a cover it should have one, but does this apply to 'home made' bits?

Regardless of what the BSS says, it is very inadvisable to have bare terminals, copper strips etc connected to battery positive. An accident waiting to happen. The same things connected to battery negative can of course be left without covers

[robtheplod]

Quick question, getting shopping list together of bits I'll need and thinking about my nuts!

 

Is there any reason not to use stainless steel Nyloc nuts on battery terminals to hold the battery cables on?  I can't recall seeing any before but can't think of a reason why this wouldn't be a good idea unless missing something obvious?  any views?   their resistance to vibration must be a good thing?

[Tracy D'arth]

Nylocs  will be a pain when you are trying in the dark to undo a terminal with one spanner.  Why re-invent hassle for yourself, terminal nuts don't shake loose anyway, never have.

[nb Innisfree]

11 minutes ago, Tracy D'arth said:

Nylocs  will be a pain when you are trying in the dark to undo a terminal with one spanner.  Why re-invent hassle for yourself, terminal nuts don't shake loose anyway, never have.

Stainless bit is OK though. 

[nicknorman]

Nyloc doesn’t keep a tension, it only stops rotation. And in the event of an overheat due to high resistance, then the nylon melts and flows out. Better to use a spring washer which will keep tension as well as resisting undoing of the nut (not that it’s likely to want to undo itself). Or just a nut!

[Tracy D'arth]

I want to see how you are going to connect things that have terminals built in with 95mm cable. 

[robtheplod]

13 minutes ago, Tracy D'arth said:

I want to see how you are going to connect things that have terminals built in with 95mm cable. 

so do I