Panel re-install issues

[MulchP]

Hello

A couple of weeks ago I had one of my 26 panels replaced as a result of a squirrel/fire. When the techs were done I came out to take a look and was not pleased. Since I had these installed a couple of years ago they were not able to source the same exact panel. That I completely understand but the problem was the the new one had a frame that was not the same thickness as all of the rest. As a result the techs could not use the Same T bolts to secure it. They ended up mounting it independent so it is lower and offset from the rest. Luckily it was an end panel but literally it sticks out like a sore thumb. I contacted the company and said that I was not happy with the look and can they conceive an idea to shim it up so it would fit with the rest. Their response was that was not an option. They said the T bolts ground the panel. I understand that but the only place the T bolts contact the panel is on the top. I have a pic to show of my original install. Are they correct or could I shim it up? I was thinking of 3D printing something out of PVC. If needed I can create something out of Al. Correct me if I am wrong.
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[bob-n]

It's true that there seems to be a general trend to thinner panels. I don't know if thicker panels are still available. Can you find out the thickness and size of the old panel, then try calling a few web dealers to see if they have any of that size available? It has to be the same X, Y and Z, and same number of cells. You can find many dealers with a simple google search.

As to adapting the mounting, yes, it is fairly easy. Get some solid aluminum of the right thickness and bolt it to the panel with stainless screws and stainless nuts. Then install the combination just like any other panel. Getting aluminum of the right size might mean buying larger and machining it.

There's one more concern. If your system uses a string inverter and has multiple strings in parallel, it is important to match panels. In most other cases, panel matching doesn't matter.

[littleharbor]

Pretty ugly. I don't blame you for being upset. Whoever installed that panel couldn't have cared less about the aesthetics of your array. That is one huge gap

[J.P.M.]

Get some solid aluminum of the right thickness and bolt it to the panel with stainless screws and stainless nuts.

You know about thread galling ?

[J.P.M.]

How is the east side of that upper panel attached to the rail ?

Also, any thought to putting a critter guard/mesh around the array ?

[Ampster]

The grounding is often done where the panel rests on the racking and in that case is done with a thin serrated SS device that sits between that interface. In one sense they may be correct but their lack of problem solving skills is evident.
A simple workaround would be to use grounding lugs and wire to ground the panel to the rail so that it can be raised by a shim.

[bob-n]

JPM brings up a good point - thread galling, where friction from tightening bolts causes the bolts to deform and jam. I've been bit by it. It can be very discouraging. It's a relatively high risk with stainless fasteners.

You can avoid galling by lubricating the bolt before assembling. It is a worse problem with high-speed assembly (power drivers) and high-torque fasteners. Any oil, grease or wax will reduce the risk. Special anti-galling compounds also exist. Ironridge now supplies their fasteners with an anti-galling compound pre-applied.

But you may not have to worry about galling when you hand assemble an aluminum spacer to the panel frame with 8-32 or 10-32 screws and nuts.

[J.P.M.]

JPM brings up a good point - thread galling, where friction from tightening bolts causes the bolts to deform and jam. I've been bit by it. It can be very discouraging. It's a relatively high risk with stainless fasteners.

You can avoid galling by lubricating the bolt before assembling. It is a worse problem with high-speed assembly (power drivers) and high-torque fasteners. Any oil, grease or wax will reduce the risk. Special anti-galling compounds also exist. Ironridge now supplies their fasteners with an anti-galling compound pre-applied.

But you may not have to worry about galling when you hand assemble an aluminum spacer to the panel frame with 8-32 or 10-32 screws and nuts.

FWIW, after a lot of time/effort designing bolted/gasketed joints for structural, pressure containing and other applications, some ways to reduce the probability of a galled/seized joint:

- Don't use materials that have a high(er) propensity of cold/friction welding.
- Start with different materials. If st. stl. is the material used for bolts/studs/nuts, austenitic 304 or 316 bolting and harder nuts of a martensitic stainless such as 431 are a good start. Al-bronze nuts are better yet as long as the environment is non corrosive to the nut material.
- Having a greater hardness diff. between nut and bolt helps reduced the probability of galling. 304 and 316 st. steels probably don't have that much hardness diff. between them to be used together.
- Use cold rolled rather than machine cut for threaded products. The cut threads may also have burrs that make things worse.
- Thread lubricants can be useful, just don't use too much. Crevice corrosion cracking can be a result.
- Too much of a thread lube that contains graphite can cause galvanic corrosion. Use very sparingly.
- Do not use the nut/bolt to draw two components structural components together. Mate components before tightening.
- Do not use power tools to tighten a joint or even spin down a nut. I know it's tempting, but it's often too much friction in too short a time.
- Tighten S-L-O-W-L-Y.
- Always use a torque wrench. DO NOT OVERTIGHTEN.
- If the required torque increase with tightening: STOP. It'll only get worse and harder to correct if you don't.

The more of the above measures you consider, the greater the probability you'll have of avoiding a galled/seized threaded joint.

Take what you want of the above. Scrap the rest

[bcroe]

The key here is not to over tighten. With so many decades of tightening wrenches, I
can deal with most without a torque wrench. Power tools are for taking apart, assemble
by hand. Lube is good, not always convenient.

Part of the incentive to tighten is preventing it coming loose later. If there is something
in the stackup softer (like wood) no amount of tightening will assure it will not shrink later
and loosen up. My standard fix is to tighten a second nut against the first, which will not
come loose no matter what the stackup does. Alternate methods are some single pieces
like elastic nuts (not trusted here long term under the sun) and distorted thread nuts.
Problem with these is they resist you all the way on to contact, and you do not control
the locking torque. Bruce Roe

[MulchP]

The grounding is often done where the panel rests on the racking and in that case is done with a thin serrated SS device that sits between that interface. In one sense they may be correct but their lack of problem solving skills is evident.
A simple workaround would be to use grounding lugs and wire to ground the panel to the rail so that it can be raised by a shim.

Yes exactly. Where is the problem solving. I teach engineering and design at the HS level. If one of my students came to me with this solution I would probably throw something at them. Ridiculous.

Some of you are discussing attaching a shim to the panel. That I am told is not an option as that would void any warranty. My solution is to design and print (ABS) a shim that hugs the rail and the panel sits on. Grounding is not an issue as you can see from the pic that the their is about 1/8" clearance from panel to clamp. The only connection between panel and clamp is at the top, and side. If grounding is an issue again a simple solution is a wire. Easy as pie. I would do this my self but, that is what I payed them for. My days of climbing on an 8/12 two stories up are over.

How is the east side of that upper panel attached to the rail ?

Also, any thought to putting a critter guard/mesh around the array ?

The E side has under mount clamps. They ran out of room on the rail. Isnt that a bit of a signal that they should lean to my idea?

I passed on the critter guard. $1300. The problem is resolved. I cut down a tree and will trim back the other. I saw the nest last fall and said to my self that I was going to get up there this srping to clear it. They beat me to it.

Still waiting to hear back from the service manager. I hoping that she has more insight this time. If not I will go higher. This not only looks bad on my roof it looks bad on them as an installer. Half ass'n it.

The waiting begins.

Thanks guys

[bob-n]

The ABS shim idea may be OK, but it's adding another material to the stack. Is that ABS UV stable? We expect our panels to last 20+ years. I'm skeptical of plastic doing the same, without a lot of testing and history. Also, ABS is not within the design parameters of your rack. Solar racking is engineered and tested (and warranteed) with aluminum framed panels.

But you're doing the right thing. Work with the installer to have it done correctly. That means getting the right replacement panel, not adapting the wrong thing.

I'm looking at the website for a reputable dealer, AltE www.altestore.com They sell panels under the brand Rec Twinpeak in 30mm and 38mm thicknesses. They sell panels under the Q-Cells brand that are 35mm thick. They sell panels under the Peimar brand that are 40mm thick. One of those has to be correct. If AltE has it, any Solar dealer can get it. Also, there are many more suppliers with stock comparable to or better than AltE. I really think that your installer can get what you need without adapting.

Please let us know how this works out.

[sdold]

You might be right, Bob, the plastic might compress over time and the bolts would lose preload and the panel would loosen up.

[Mike90250]

Aluminum, corrosion, mill finish, clear anodize

Aluminum has a pretty unique property, in that within a few seconds of exposure to oxygen in the air, raw aluminum almost instantly develops a hard, insulative oxide layer.
(Aluminum Oxide Sandpaper is a use for it)

Over time (just a couple of years) it will grow into a fuzzy white mass and then you will see some slack in the bolt torque. That's why only a few schemes using SS tooth washers or special clips are certified for grounding panels. Factory panels always (from reputable factory's) have been clear coated with some anodize finish, (or black anodize) to prevent this creeping crud.
You may have seen it on cheap builders special aluminum windows or shower/bath doors

So be careful about adding chunks of hardware store aluminum, as it's not been coated the same way as your panels.

[MulchP]

Yes the ABS is probably not the best solution. I’m just brainstorming ideas which now that I think about it is there job. I may need to just chill and use the written word to get this done. This is on them. As I said this look is there doing so if this what they want to be know for so be it. I’m still waiting for their latest response and if it isn’t the best solution I will go higher. The waiting game begins.

Thanks