Copper tape vs cable

[tonyg]

Solar diy market is very small in the UK and components are not easy to find, that includes wires. For example, finding good quality 120mm2 wire in red is harder than anything. Finding T-Class fuses is as hard as getting a ticket to the moon...

Anyways, I had a thought, it seems a bit off-the-grid to be fair... I found pretty accessible price wise, bare copper tape (25mmx6mm).

• Can I use this from the inverter to my Lynx Power In to replace the two 70mm2 wires (2x positive, 2x negative as per the manual)? I suppose I won't need to fuse it then, right? :D
• Can I use this instead of the battery cables (120mm2 wires)? Do I still need the class T fuse?

Of course, I can nicely dress the copper tape in some black and red heatshrink, after bending it as necessary. :D

T

 

[rmaddy]

When you say 25mm x 6mm copper tape do you mean copper bar that is 6mm thick, 25mm wide, and can be cut into whatever length you need? Such copper bar has a cross section of 150mm² so it is equivalent to wire of that size.

Copper bar can be used in some places (the bus bars inside the Lynx are copper bars). But you can't use it like general purpose wire since it can't be bent or inserted into most terminals and it can't have lugs crimped onto it.

But if you are actually talking about some really thin copper foil tape (then I don't understand what your dimensions represent), then no, it can't be used either. You need real proper stranded copper wire.

 

[Shimmy]

Can you get Marine Rated Battery Fuses (MRBF) in UK? Suitable alternative to Class-T.

 

[tonyg]

When you say 25mm x 6mm copper tape do you mean copper bar that is 6mm thick, 25mm wide, and can be cut into whatever length you need? Such copper bar has a cross section of 150mm² so it is equivalent to wire of that size.

Copper bar can be used in some places (the bus bars inside the Lynx are copper bars). But you can't use it like general purpose wire since it can't be bent or inserted into most terminals and it can't have lugs crimped onto it.

But if you are actually talking about some really thin copper foil tape (then I don't understand what your dimensions represent), then no, it can't be used either. You need real proper stranded copper wire.

It would be like copper bar yes... They call it tape, but it is very solid. I've bought the 25x 3mm one and using it for battery busbars. It is definitely not copper foil.

 

[tonyg]

Can you get Marine Rated Battery Fuses (MRBF) in UK? Suitable alternative to Class-T.

What's the difference with Class-T fuses? I had a quick look on eBay and I can see a 300A one from BlueSea, and that's good.
Most system schematics I saw use Class-T fuses though...

 

[A.Justice]

What's the difference with Class-T fuses? I had a quick look on eBay and I can see a 300A one from BlueSea, and that's good.
Most system schematics I saw use Class-T fuses though...

Class T fuses are capable of interrupting the massive current that lithium batteries can produce. MRBF's are mostly used on lead acid batteries, and can't interrupt the current potential on a large lithium bank. There are other fuses with high interrupt ratings, but class T is the industry standard for lithium batteries.

If you're having trouble finding them, eBay is my go-to. There's lots of new, old stock on there.

 

[tonyg]

Here is the eBay results in the UK for Class-T fuse 300A...

 

[A.Justice]

Here is the eBay results in the UK for Class-T fuse 300A...

View attachment 97706

I order stuff from the UK all the time, shipping is like 10 days. Is there a reason you couldn't order from the States?

 

[BiduleOhm]

Here is the eBay results in the UK for Class-T fuse 300A...

View attachment 97706

Check out NH fuses. They're basically class T fuses on steroids and are cheaper (but bulkier, so if space is a constraint it might be a problem for you), at least here (France)

 

[tonyg]

I order stuff from the UK all the time, shipping is like 10 days. Is there a reason you couldn't order from the States?

I like ordering locally if I can... Easier to have support from the seller, easier to return / replace if anything goes wrong and less postage fees and less import taxes... It all adds up in the end, but having them bought locally gives me peace of mind!

 

[tonyg]

I have found thick cable here (UK) as well, after hours of searching... I've got two options: tri-rated cable (here) vs welding cable (here).
In my case, I will go forward with the tri-rated cable, since this has temperature limits of -30 to 105 C, while the welding cable can go up to 85 C. The manual of my inverter (Victron) states "The DC cables must be copper and rated 90 C (194 F)." Interestingly, the MPPTs (Victron as well) suggest Class 5 tri-rated cable, but there is no such mention in the inverter manual.
I'll also have to add some red heat shrink since it seems it comes in black only, but otherwise should be fine. I hope to make a list of suppliers and post it in a new thread, so anyone in the UK can use them - I've spent ages looking for stuff. I am still searching for fuses though!

 

[BiduleOhm]

I am still searching for fuses though!

https://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=nh+fuse&_sacat=0&LH_PrefLoc=1&_sop=15 from UK only, sorted by price, didn't excluded used ones but you can if you want

Average price seems to be under 20 £ shipping included.

 

[tonyg]

Found class-T fuses here:

Fuse Class T 300 Amp 160VDC

A remote control for MasterBus systems. Suitable for local device monitoring. Buy online today, UK shipping

www.fischerpanda.co.uk

They have them in stock, ready to dispatch! :D