Broke terminal bolt on new Victron MPII inverter

[Skypower]

I do use a torque wrench but don’t trust it. What I mean is I set the torque setting then slowly start to tighten it. “does this feel right?” as I go. I only tighten to what feels right or reasonable. I might go a tad more than that to see if I hit the click of the wrench, if not I’ll stop. So I trust my own hands first and the wrench second. To set the wrench and trust it completely is just asking for trouble.

Before I learned this skill, I completely bent and wrecked my rebuilt-by-me carburetor because I over tightened it. I didn’t own a torque wrench at the time and assumed I should just tighten ‘er down good and tight. Car got about 2 miles to the gallon after that…

What I’ve learned over the years both with and without a torque wrench, generally it’s better to go a little light than too tight. Especially with plumbing, but it works good for about anything.

When I started using a torque wrench to tighten my lug nuts on my car and truck wheels, I was amazed at how light the speed torque is. For years I had really been cranking down on them, which I now know isn’t necessary. Unsure of the accuracy of my torque wrench, I went to the local tire shop, who know what they’re doing and they had the same result as my torquing.

I can’t tell you how many times I’ve thought, this can’t be right and stopped or re checked the torque wrench.

 

[Tomthumb62]

I can’t tell you how many times I’ve thought, this can’t be right and stopped or re checked the torque wrench.

A torque wrench is only going to do what it’s set to do, which might be inaccurately calibrated. It can’t think. Glad you used your noggin!

 

[JRH]

Yesterday, after nearly a week spent fully assembling a new complete system ordered from CC, I was torquing all the connections. The final connection to the Victron MPII 3kva inverter negative, the terminal bolt twisted off. The torque spec is 12nm, my wrench goes to 11nm and had just successfully torqued over 20 other connections.

While doing a little research on the issue yesterday I found someone with the exact model inverter, who broke the exact same bolt. https://community.victronenergy.com...ii-battery-terminal-bolt-snapped-sheared.html

I sent an email first thing this morning to CC to see how to proceed, will update as it evolves.

Meanwhile, does anyone know a fix, or will any attempt invalidate the warranty?

Considering getting a Phoenix to fill in until this is fixed.

Thoughts?

A company can tell when they are at the tip top when even a small mishap of somthing they didn't even have control over , generates big news..haaa
A bad casting of an item can crack or break off… had it happen many times in manufacturing Gold rings from the lost wax process…usually due to porosity but there can be a few other reasons..…you can tell by looking at the break… it will look granular and rough , not clean and smooth..
there’s worse things that can happen to a new piece of equipment…

 

[l00semarble]

To OP. You are not the first person to have this happen. I wouldn’t immediately blame the torque wrench. Work with your dealer and Victron wil likely make this right.

 

[HalfBaked]

To OP. You are not the first person to have this happen. I wouldn’t immediately blame the torque wrench. Work with your dealer and Victron will likely make this right.

Thanks, but ultimately, it was totally my fault for trusting a borrowed torque wrench. I won't make that mistake again.

But you're right, I did work with my dealer, Current Connected. They did not justifiably blame me, or charge me for the repair or even shipping cross-country. The whole process was smooth as glass and took about a week round trip.