Terminating large cables

[Ann3x]

Im reworking my van's leisure wiring atm, plan is as follows:



Im keeping pretty much the same setup as I have now (as it's working pretty well), just a few minor rework jobs:

• Moving the HUP & Consumer unit
• Adding a trickle maintainer for the starter (cable may be reused in future for solar charging the starter, hence the uprated size)
• Consolidating various single fuses into a fuse box (instead of the functional but messy set of random individual load fuses my converter left)
• Conduit & mounting space for battery monitoring and solar cabling which are both on the longer term plan
• General tidy up of the cabling spaghetti whilst I have the cab out for sound deadening etc

Mostly the job is going ok but as I tidy up I'm having some minor issues, especially with the larger cables. For example:

• The 6AWG cables going into the B2B are crammed into the charger's screw joints with lots of strands not in the terminals (converter put this in.... I guess just rushed it...)
  • 16mm/6AWG seems to be widely recommended for B2B systems so I guess this must be a common problem, surely just "shove it in" is not the right way....?
• The DS Load cable is terminated with a ring terminal / strip fuse that wont allow me to consolidate into the blade fuse box as the cable is too large for yellow spade connectors.
  • How do people get larger cables into a blade fuse box? Does it HAVE to be midi/maxi fuses for these larger cables? I assumed blades would be ok as you can get 40A fuses in the format.

If others have dealt with these sort of problems itd be useful to know how you solved them, I've not dealt with the larger cables before.....

Any more general feedback on my setup (whilst its all out)? I'd like this to be the last time I have the floor up if at all possible.

 

[oldiebut goodie]

I envisage that something like these cable reducers are what you are looking for - it is something that I have thought about but have never gone as far as to buy some and use them!

 

[Ann3x]

I envisage that something like these cable reducers are what you are looking for - it is something that I have thought about but have never gone as far as to buy some and use them!

Yes I had thought about something like that... The concern is just whether it down rates the whole run.... But I guess its the same as per current for the b2b.

 

[travelvolts]

16 mm for a DC-DC charger is only usually indicated if the cable run is 5 metres or more. In your case 10 mm would be more suitable, assuming that the Sterling is the 30 amp version?
If you change your fuse boxes for single entry types you can fit the supply cables with proper lugs appropriately sized for your cables.

 

[Ann3x]

16 mm for a DC-DC charger is only usually indicated if the cable run is 5 metres or more. In your case 10 mm would be more suitable, assuming that the Sterling is the 30 amp version?
If you change your fuse boxes for single entry types you can fit the supply cables with proper lugs appropriately sized for your cables.

I actually got the fuse box from you @travelvolts 6 way fuse box | travelvolts what do you mean by single entry, not sure I understand? Do you mean a fuse box with screw terminals instead of spades? I chose the one linked because of space restriction and the fact that only a few feeds are needed.

If possible ill leave the 16mm cable in place (up rated cant hurt, right), would a reducer lug to terminate in the B2B like @oldiebut goodie suggested be a sensible (& safe) option you think?

 

[Jack T]

So fuse box is easy enough just use a copper tube ring crimp of the appropriate size to feed it. 10mm in the photo below in and out but 16mm would fit easily.



If you are going to use the 16mm into smaller terminals then use pin crimps as below. Buy a proper hydraulic hexagon crimp tool they don’t cost the earth but make sure of a good connection. I always use some adhesive lined heat shrink with these as per the picture above as it makes for a tidy job.

Another option to reduce size is go to a midi fuse holder first fuse it down - drop the cable size - go into whatever you are feeding.

HTH

 

[travelvolts]

I actually got the fuse box from you @travelvolts 6 way fuse box | travelvolts what do you mean by single entry, not sure I understand? Do you mean a fuse box with screw terminals instead of spades? I chose the one linked because of space restriction and the fact that only a few feeds are needed.

If possible ill leave the 16mm cable in place (up rated cant hurt, right), would a reducer lug to terminate in the B2B like @oldiebut goodie suggested be a sensible (& safe) option you think?

Okay, that is a single entry fuse box. From your earlier description it sounded like you had the old style with one input per fuse. So what are you having trouble with in terms of crimps?
Yes, you could use a cable reducer and retain the 16 mm, it won't be a problem. Do you have suitable crimpers for those?

 

[Ann3x]

Okay, that is a single entry fuse box. From your earlier description it sounded like you had the old style with one input per fuse. So what are you having trouble with in terms of crimps?
Yes, you could use a cable reducer and retain the 16 mm, it won't be a problem. Do you have suitable crimpers for those?

Just finding a spade connector thats big enough to crimp onto 8AWG cable so I can consolidate it into the fusebox.

For the 16mm I've ordered these. which will hopefully allow a better termination into the Sterling: Cembre Copper Tube Flat Pin Crimping Terminals 16mm² 6AWG | eBay

 

[Jack T]

I don’t think you are going to find easily/at all a 6.3 spade connector that will accept an 8awg cable as that’s pretty hefty. You would not normally take a supply needing that bigger cable from a spade connection.

Can you not feed each of your fuse boxes from a bank of say 3 midi fuses near your leisure battery? Or use one big fuse box fed from your leisure battery? But again you would need a midi fuse at the leisure battery to protect the supply cable?

 

[Jack T]

Or something like this near your battery to supply the fuse boxes, that’s what I use.

 

[travelvolts]

Just finding a spade connector thats big enough to crimp onto 8AWG cable so I can consolidate it into the fusebox.

For the 16mm I've ordered these. which will hopefully allow a better termination into the Sterling: Cembre Copper Tube Flat Pin Crimping Terminals 16mm² 6AWG | eBay

I would definitely be using a midi fuse on cable of that size. What is it supplying?

 

[Ann3x]

I would definitely be using a midi fuse on cable of that size. What is it supplying?

The drivers side fuse box. Fridge, inline pump and a few other small loads run off it. Diagram is in 1st post. The cable is overkill but it'd be hard to change now as its routed behind water tank, furniture etc.

 

[travelvolts]

Just fit a 5 mm lug and connect it to the input of the other fuse box.

 

[Ann3x]

Just fit a 5 mm lug and connect it to the input of the other fuse box.

Sorry I wasnt clear.

The DS fuse box is remote, its in the C pillar on the DS. This is connected to the new main fusebox via a ~3m 8AWG cable which is in turn connected to the Leisure battery.

I need a way to terminate the 8AWG DS cable INTO the main fusebox. As I see it there are only 3 potential choices:

1. Find a spade connector that accepts 8AWG cable (I cant find any from my searches)
2. Use a reduction lug (or similar) on the 8AWG cable to allow me to fit it into a standard yellow spade connector
3. Use a fusebox which accepts ring terminals (eg mid/maxi)

Im erring to the reduction lug option.

 

[Jack T]

I wouldn’t put a reducer into a crimp, that won’t work well IMHO.

Why not do as I have done in my pic above just go in and out of your first fuse box to the next. Lug in lug out. I presume you have a sensible size fuse close to the leisure battery that already protects the distribution cable?

 

[travelvolts]

What Jack says . Why does it need to go THROUGH the fuse box?

 

[Ann3x]

I wouldn’t put a reducer into a crimp, that won’t work well IMHO.

Why not do as I have done in my pic above just go in and out of your first fuse box to the next. Lug in lug out. I presume you have a sensible size fuse close to the leisure battery that already protects the distribution cable?

The main fuse box is only a 20cm run from the Leisure Battery, so I was going direct unfused and relying on the fuse box to protect the longer, more exposed runs.

Adding an inline fuse before the main fuse box to the DS cable would mean the DS cabling is covered by the main leisure fuse. So would work, but any issue with DS cabling would then take out the whole van's Leisure electrics as the standalone fuse would be before the fusebox in the circuit.

If I was going that route - as it would mean adding an inline fuse anyway (something I wanted to avoid so that all feeds were consolidated in the one fusebox) - it would probably be better to just attach the DS feed direct to the Leisure battery and fuse THAT inline. That was an issue with the DS wouldnt take out the whole van.

Instead of reducer into crimp directly, what about butt splicing the 8AWG with a 10AWG cable (of minimum possible length) and putting THAT into the spade connector?

What Jack says . Why does it need to go THROUGH the fuse box?

Just for traceability really, I wanted all my loads fused from the one box so its easier to see whats going on without digging through 4 separate inline fuses.

 

[Jack T]

Unfortunately the way I see your issue is any of the ways you are thinking are some kind of bodge which in the long run may cause you a headache. Please don’t see this as me being rude that isn’t my intention.

You either need to put a single midi fuse carrier close to the leisure battery and pass through your fuse boxes. Admittedly this will protect everything via 1 main fuse.

Or add a midi fuse box next to your first fuse box and use that for distribution only to supply each one of your others FB’s. This is the best option as I see it, just keep an eye on your loadings and make sure you don’t overload the short length from LB to midi fuse box.

In my setup I use one of the midi fuse boxes fed with 35mm cable from twin LB’s and then use the mega fuse to supply a 2k inverter. Then use the midi fuses to connect a single 12 way FB and then reverse feed the LB’s from mains charger and DCDC charger. I also have a 200amp relay so I can isolate the LB’s when not in use.

If you do the job right and have multiple fuses in multiple accessible locations it shouldn’t matter. I wouldn’t expect to have to change a fuse and if I did regularly there is a major problem somewhere.

Also copper tube crimps work in specific sizes rather than a range so you can’t get 10awg one side and 8awg the other. Putting an oversize crimp on and excessively compressing it is bad practice.

 

[Jack T]

Also for reference of OP or anyone else if it helps this is the ideal crimp tool for copper tube crimps. Multiple dies for different cable sizes.

Just making some changes using mine at the moment so thought I would share whilst to hand.



This creates an all round crimp:



And finished with adhesive heat shrink:



You can get more basic crimpers that force a pin in from the rear which are cheaper but not quite as slick. I have a few different ones as when crimping 180mm onsite you need something a little larger.

Most decent electrical wholesalers also keep these for hire. If you take the cable to them you can borrow the crimper and use it there and then for very little or even free.

 

[Ann3x]

Unfortunately the way I see your issue is any of the ways you are thinking are some kind of bodge which in the long run may cause you a headache. Please don’t see this as me being rude that isn’t my intention.

You either need to put a single midi fuse carrier close to the leisure battery and pass through your fuse boxes. Admittedly this will protect everything via 1 main fuse.

Or add a midi fuse box next to your first fuse box and use that for distribution only to supply each one of your others FB’s. This is the best option as I see it, just keep an eye on your loadings and make sure you don’t overload the short length from LB to midi fuse box.

In my setup I use one of the midi fuse boxes fed with 35mm cable from twin LB’s and then use the mega fuse to supply a 2k inverter. Then use the midi fuses to connect a single 12 way FB and then reverse feed the LB’s from mains charger and DCDC charger. I also have a 200amp relay so I can isolate the LB’s when not in use.

If you do the job right and have multiple fuses in multiple accessible locations it shouldn’t matter. I wouldn’t expect to have to change a fuse and if I did regularly there is a major problem somewhere.

Also copper tube crimps work in specific sizes rather than a range so you can’t get 10awg one side and 8awg the other. Putting an oversize crimp on and excessively compressing it is bad practice.

You're probably right and definitely no offence taken , just trying to make it as neat, logical & simple as possible. If an inline fuse is the only sensible way to go, Ill do that.

For the record tho - I have seen reducer butt joins, just not the right sizes in the UK, so not 100% convinced its a complete bodge idea eg:

MVP 10 Non-Insulated Seamless Step Down Butt Splice Connectors 10 to 8 Ga AWG | eBay

8 AWG wire. Seamless construction for. Electro-tin plated copper.

www.ebay.com

Burndy YSR4CFX8CFXLTCKITC, In-Line Reducer Splice Kit, 4 AWG to 8 AWG, w/ Clear Heat Shrink

Burndy YSR4CFX8CFXLTCKITC, In-Line Reducer Splice Kit, 4 AWG to 8 AWG, w/ Clear Heat Shrink and inspection window.

www.wireandcableyourway.com

Amazon.com

GTSE 25 Pack of Yellow Heat Shrink Butt Connectors – 6.5mm Entry - Premium Waterproof Crimp Terminals : Amazon.co.uk: DIY & Tools

Shop GTSE 25 Pack of Yellow Heat Shrink Butt Connectors – 6.5mm Entry - Premium Waterproof Crimp Terminals. Free delivery on eligible orders of £20 or more.

www.amazon.co.uk