I've got Spaghetti- any Wire Management & Tying tips??

[bcroe]

Lots of ways to route DC wires, and local regs vary as well. Mine are pretty much not accessible
by the public. The finger trough is nice, but needs support and is quite expensive. I have snow
gaps, so single wires crossing these gaps are positioned for protection. Bruce Roe



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[DanS26]

Bruce, you have done a lot of strange things with your solar system, but this wire management takes the cake. WOW.....just WOW!

[peakbagger]

I had to cover the back of my array to make it "inaccessible" I used hardware cloth. The loops sit between the panel and the hardware cloth.

[GRickard]

It looks like all those loops would cause heat build-up. You're creating a coil.

[SunEagle]

It looks like all those loops would cause heat build-up. You're creating a coil.

You have heard of heat tracing to keep things from freezing?

[DanS26]

Here is a very good article on wire management and latest industry techniques:

https://solarprofessional.com/articles/products-equipment/racking/pv-array-wire-management#.WgrqUXVJGkc.gmail

[bcroe]

Here is a very good article on wire management and latest industry techniques:

Wire management seems to be left to the local installer in many areas, with varying results.
That article eventually does mention some available systems, not much detail or pictures.
I wonder why they don't want the wires in a tray, but conduit is OK?

One thing it said:

"module leads are too long for portrait installations and too short
for landscape installations".

That is true, and I'll be dealing with it while converting the present portrait mounts to landscape
mounts. Probably reverse some panels so as many as possible will reach, then add (custom length)
MC4 extension cords. The installer left lots of PV wire scraps typically with an MC4 on one end. I
gathered these and put mating MC4s on the other end; these have been handy.

Colored coded PV wire is mentioned as having a shorter life in sun than pure black. I go with that,
using lots of custom labeling of components and wires. These are cut up pieces of bumper stickers
created and ordered on line. Critters chew many things, but metal seems to stop them all.
Even better if part of an electric fence.

No mention of heat shrink tubing, my carryover from electronic and car wiring. Bruce Roe

[sensij]

The version of skip wiring I used with my optimizers resulted in some panels with two optimizers underneath and some with none. Anecdotally, the panels with more optimizers underperform those with none (optimizers are a heat source, and/or interfere with airflow), but I haven't done a controlled comparison yet.

+1 on the aggravation induced by those star washers. Taking apart every diamond bolt just to thread it on was tedious, especially since the optimizer itself is slotted and can slide right on the bolt.

I bought what seemed like an excessive amount of iron ridge wire clips, but used them all. It wasn't pretty, but the wires were contained enough that I was satisfied with the result.

[J.P.M.]

The version of skip wiring I used with my optimizers resulted in some panels with two optimizers underneath and some with none. Anecdotally, the panels with more optimizers underperform those with none (optimizers are a heat source, and/or interfere with airflow), but I haven't done a controlled comparison yet.

+1 on the aggravation induced by those star washers. Taking apart every diamond bolt just to thread it on was tedious, especially since the optimizer itself is slotted and can slide right on the bolt.

I bought what seemed like an excessive amount of iron ridge wire clips, but used them all. It wasn't pretty, but the wires were contained enough that I was satisfied with the result.

I've no doubt about what you're writing with respect to possible temp. sources and impairment of heat transfer with respect to optimizers.

~~ size of optimizers ?
Optimizer efficiency ?? --- >>> waste heat generation ??
separation distance, optimizer to back of panel ? Flush/zero clearance ?

Just askin/wonderin'. Maybe a bit more than anecdotal ? Perhaps hard to quantify/isolate.

[AzRoute66]

I know it wouldn't be to [current] code, but four or five 6' runs of something that looks a lot like that Panduit 'finger' tray (non-conducting, but fully UV/weather resistant) would have been a pretty good solution for Syberdog's array, better than cable ties and/or rail clips alone. A good longer term first step is integrating the micro-inverter/optimizer with the panel, although I would prefer something that attaches directly to the junction box rather than fully contained within it.

[bcroe]

Optimizers are a switching converter technology. Quite efficient, maybe 98% compared to that
20% panel. I think it would be hard to detect a heat influence from an optimizer. Bruce Roe

[foo1bar]

I think it would be hard to detect a heat influence from an optimizer.

The key question is: How much difference in temp will it make between the two modules?
I think many modules are about 1/2% production loss per degree C.
So if you have a 4'C difference between panel A and panel B, it's a 2% difference.
And that's probably significant enough to be detectable.
An additional 10W of heat (2% * 2 modules * 250W/module) and the obstructed airflow I think could be enough to make a 4'C difference.

[sensij]

The key question is: How much difference in temp will it make between the two modules?
I think many modules are about 1/2% production loss per degree C.
So if you have a 4'C difference between panel A and panel B, it's a 2% difference.
And that's probably significant enough to be detectable.
An additional 10W of heat (2% * 2 modules * 250W/module) and the obstructed airflow I think could be enough to make a 4'C difference.

I think the temperature effect probably plays out on a individual cell level more than a module level. Because the cells making up a module are in series, increasing the temperature of the cells closest to the optimizer should primarily reduce the Vmp of just those cells, with little effect on cells that are further away (I doubt there would be much of a cell-to-cell conduction heat flow).

Anyway, I'm aware that the fundamentals don't suggest that much of an effect would be present, but until I can more rigorously analyze my data, I'm just throwing it out there (perhaps irresponsibly) as food for thought.

[bcroe]

There are the opinions; now somebody needs to resolve by making actual measurements. it won't
be me (this time) since I don't have optimizers. Bruce Roe

[J.P.M.]

I think the temperature effect probably plays out on a individual cell level more than a module level. Because the cells making up a module are in series, increasing the temperature of the cells closest to the optimizer should primarily reduce the Vmp of just those cells, with little effect on cells that are further away (I doubt there would be much of a cell-to-cell conduction heat flow).

Anyway, I'm aware that the fundamentals don't suggest that much of an effect would be present, but until I can more rigorously analyze my data, I'm just throwing it out there (perhaps irresponsibly) as food for thought.

As a 1st approx. and depending on a lot of stuff, the (local) heat added to a panel due to optimizer propinquity and optimizer heat generation of say 2% of panel output, will probably be close to the same amount of heat not rejected due to inhibiting convective teat transfer from the panel by optimizer placement that lowers the convective heat transfer and thus increases (local) panel temp.

How much ? Maybe the 4 deg. C. that Foo1bar suggests, +/- a degree or 2 at or around the optimizer. Depending on location and the panel configuration, such local temp. differences may/may not affect the entire panel output, but I bet it'll sure be hard to nail down.