[boekel]

busbar insulation

I want to insulate some busbars, and wonder if other people have found a goo working solution...

Heat shrink tube works but around corners not so nice:

Then I tried PU-Rubber:

It works but needs multiple layers, and this particular type has a short pot life until it's not longer usable...

Did someone find a better solution?

 

[john61ct]

"Liquid Electrical Tape"

"Plasti-Dip" for tool handles similar but thicker

 

[major]

You can always use tape. Flexible glass tape or even cotton cloth. Then impregnate with a varnish or polyester resin. There is, or was, pretaped rectangular copper bus called "double dayglass". Bars can be bent and formed. The tough task is removing the insulation for the connects. Had to grind or sand it off.

http://www.samdongamerica.com/products/special-insulated-rectangular-wires

Google brought up this outfit. Some examples there. Also nowadays Kapton tape is an excellent choice.

major

 

[GoElectric]

I'm interested to see further efforts and your thoughts on them. Perhaps a combination of heat-shrink for the straight sections, and tape on the corners? You can then use red and black (for both, if it matters). I can see the goop being very time-consuming and messy.

Hmmmm, I'll also add: Why does it matter so much?

Also, nice job - how did you make them? Is that silver-plated copper??

 

[boekel]

I'm interested to see further efforts and your thoughts on them. Perhaps a combination of heat-shrink for the straight sections, and tape on the corners? You can then use red and black (for both, if it matters). I can see the goop being very time-consuming and messy.

Hmmmm, I'll also add: Why does it matter so much?

Also, nice job - how did you make them? Is that silver-plated copper??

High Voltage needs to be orange.

I'm building a 100kWh Battery for my boat, during construction I want the least possible chance for touching with other parts. After connection a cover will be placed, but there will be moments where quite high voltages will have to be connected.

These busbars are made from aluminium, cut and bent by www.247tailorsteel.com
18x3mm so 54mm^2 (maximum current will be low, about 100 amps only for a short time)

 

[john61ct]

Re: busbar insulation

Why aluminium rather than copper?

 

[boekel]

Re: busbar insulation

Why aluminium rather than copper?

This company doesn't supply copper, aluminium is cheaper, etc.

connections will be made with anti-oxidation grease just as needed with copper.

this 52 square mm aluminium has the same resistance as 35mm^2 copper.

Car batteries usually have 25mm^2 copper btw

 

[GoElectric]

No-doubt the aluminum that size will be fine.

When I said " Why does it matter so much?" I was asking whether it really matters how perfect the heat-shrink fits on there. I've been heat-shrinking 1"x1/8 copper busbars, and the corners are slow to do, not great, and not always easy to get on after the material is bent. Plus, the darn things get hot! I get that part, but unless it has to be show-quality, I don't think I'd go to the trouble of (possibly masking and) dunking it multiple times. Like I said, I'd be interested to hear your trials and tribulations and what you decide upon.

Hmmmm, it looks like you are committed now??

Ahhh, all orange - I suppose.

 

[boekel]

I've ordered some 3:1 orange heat shrink tube to try

Thinking about putting in the oven to see how that works out. The tube doesn't heat up well where in contact with the busbar, so maybe just put a batch in the oven at ?? temp. to heat everything evenly.

And yes, it has to be show-quality

 

[GoElectric]

"And yes, it has to be show-quality" Hahahaha - of course!

The oven might work, give it a try!

BTW, 100kWh - wow! Do you have a thread I've missed?

 

[major]

Possible to use hard or rigid snap together plastic shell, molded or 3-D printed?

Or mask the ends and have the bars powder coated?

Just throwing some thoughts out there.

major

 

[Yabert]

Have the same problem than you at job. Shrink tube give a nice finish with some busbar, but not so good with some others types like yours.
Hope your 3:1 shrink will help. I'm interested to see the result.

Another technic seem to add the shrink tube before bending the busbar build from a strait busbar (pic from chevy volt). Of course, this work well with laminated or thin busbar, but it's probably impossible with your solid busbar.

 

[boekel]

Powdercoating is a good idea too!

A ridgid 'snap-on' version I'm contemplating, also because I can cover the bolt itself for even more safety...

It's for this boat:
http://www.diyelectriccar.com/forums/showthread.php?t=126666

http://boekel.nu/foto/17/2017-08boot/image8.htm

 

[john61ct]

Re: busbar insulation

I didn't think powdercoating was electrically insulating?

There are 2-part high-density urethane foam kits, say 6-8 lbs/cu ft, that can be brushed over the bars.

If you really want to be thorough, make a lid mold, get everything in place on the batt, cover with 6+mil plastic, spray with mold release, and pour-mold a flexible foam lid that will cover the whole top.

 

[GoElectric]

I had a look at your boat. I don't know much about boats, but nice to have an image in mind. What is the OVING1 used for? I don't see any equipment on there, nor any signs that someone lives on it (?).

I'm also not sure of the dielectric strength of powder-coat. I think it would be brittle and might eventually crack. IMHO if you want it to look 100% the best way is to dip, as you have done. Costs time, not money. Making plastic covers is a really nice idea, and probably the safest, but a bit over-the top for a one-off?

 

[major]

Done right, powder coating is used to insulate bus bars and plates.

From: https://www.materialstoday.com/powd...es/epoxy-powder-coating-as-a-high-dielectric/

I think the first time I saw it was in the EV1 PEB (Power Electronics Bay). It was used on the 400 V bus. Very effective. From the early 1990's IIRC.

major

 

[john61ct]

Re: busbar insulation

Aha, so a specific material, powder coating as a method.

As opposed to more generic "powder coat" metal finish like you get on a trailer.

 

[boekel]

I had a look at your boat. I don't know much about boats, but nice to have an image in mind. What is the OVING1 used for? I don't see any equipment on there, nor any signs that someone lives on it (?).

It should be my house sometime in the future, but been busy with batteries and stuff...already did a lot of work including new bottom plating and complete super structure.
Have a nice 1 ton crane on it, and at the moment the wheelhouse is my workshop and downstairs storage...

This is some standard insulation, very nice but not easy to reproduce: