Panels going up

Surfpath · February 2013

Well, I'm a little tired of loooong generator absorb times, SO the panels are going up.

This Sunday I got the Unistrut rails bolted in and 6 of the 9 panels up (ran out of sunlight couldn't get to the last 3). All looks good and secure for now.

My panel setup:

Each panel: 220 Watts, VOC: 36.29, IMP: 7.65 amps
3 strings of 3 panels in each string: 9 panels in total: 1980 watts
VOC of ~ 108 from each string to the MNPV-4TYCO box (comes with fuses, not breakers).

The panels on the roof are clamped in but not connected yet. The TYCO leads are just taped to the underside of each panel. The pre-wired combiner box is, however, ready to go.

While I have a pause, anything I should be keeping an eye out for?

My uncertainities are as follows. I really do not know much about the Outback FM80 that sits on my flexpower panel. When I got to page 53 on the CC manual I realized that I had learnt very little. It (ie. the CC display) is not on yet. I guess it needs power from the panels to "come alive". I wish there was a "FM CC for Dummies" guide. Maybe there is actually not much to it. Put in parameters, a la inverter charger, and let it do its magic?

I also need a panel wiring diagram (to make sure I dont plug the wrong tyco leads together). I will research this in the next few days. Trying to put it all together, a little aprehensive, will try to provide a diagram of what I'm doing before I plug everything in.
-SP

westbranch · February 2013

Re: Panels going up

We need some pics pleassssssse..... never know what we might see to advise on...

Based on my MX60, you need to know your Absorb and Float voltages before you plug into the batteries, which you do before throwing the PV switch. doing this in reverse should get you a blank screen ...

get some red coloured tape for the pairs of PV + wires, makes it clear which goes where, & don't forget to number them to so you know which group you will be disconnecting at some future date.
Wiring diagram for sure.
test each arrays performance , one at a time, use the CB as a switch.
good SUN and tight connections.

Eric L · February 2013

Re: Panels going up

I guess it needs power from the panels to "come alive".

Typically, a charge controller needs to be connected to the batteries (and the breaker on) to turn on.

techluck · February 2013

Re: Panels going up

Yes, always connect the batteries to the charge controller first.

As for wiring the panels, they are just + and -. Did you decide on what voltage you want to send to the charge controller? That will tell you how many panels you want in parallel or series.

And the voltage you want to use depends on the specs of the charge controller, remember that the Open Circuit Voltage on a 24V panel is higher than 24V, somewhere near 40V so don't go over the max voltage on your charge controller. I don't know if it goes to the 108V you said.

The voltage will also help you decide on the wire size, higher voltage has less wire loss, so if you have a long run of wire, like 100 ft you may want bigger size wire. There are wire loss calculators online, use google.

You could dedicate 2 or 3 of those panels to a electric water heater using the new Solar Hybrid Hot Water Controller and with a little conservation, have good hot water.

vtmaps · February 2013

Re: Panels going up

westbranch wrote: »

We need some pics pleassssssse..... never know what we might see to advise on...
<snip>
test each arrays performance , one at a time, use the CB as a switch.

Pics are a good idea.

westbranch, I don't think he can test each array's performance as you suggest because he has fuses, not circuit breakers. For exactly that reason I did advise the OP (in another thread) to have Midnite make him a box with breakers instead of fuses.

Surfpath, if you have a DC current clamp meter you can easily test the individual strings without having to make or break connections.

--vtMaps

Surfpath · February 2013

Re: Panels going up

vtmaps wrote: »

Pics are a good idea.

westbranch, I don't think he can test each array's performance as you suggest because he has fuses, not circuit breakers. For exactly that reason I did advise the OP (in another thread) to have Midnite make him a box with breakers instead of fuses. [Yes, VT I heard, but I could not get this ordered in the TYCO version - at least not in time for my shipment]

Surfpath, if you have a DC current clamp meter you can easily test the individual strings without having to make or break connections.

--vtMaps

Yes, I will try to post pictures. Camera got 'squished' climbing up on the roof

, have to borrow the wife's. I don't have a DC Clamp meter (just a regular multimeter).

Hi Techluck, thanks for the tips. BTW my solar panel set up (ie 3 strings of 3 panels each) was discussed in a previous thread.

Westbranch, thanks for the tip about the red tape. I'm also researching panel wiring examples now. I plan to finish the installation on Thursday.

Joe_B · February 2013

Re: Panels going up

If you are installing these panels to the racks yourself, don't forget the anti-seize on the S.S. hardware. Don't ask me how I know this!

Surfpath · February 2013

Re: Panels going up

Joe_B wrote: »

If you are installing these panels to the racks yourself, don't forget the anti-seize on the S.S. hardware. Don't ask me how I know this!

Thanks Joe, good tip.

OK, I got tired of looking for wiring examples. Came up with my own off the top of my head. Reminder: total newster here, please be gentle.
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Surfpath · February 2013

Re: Panels going up

OK, about to plug things in shortly. Hope I have the wiring right.
SP

NorthGuy · February 2013

Re: Panels going up

Surfpath wrote: »

OK, about to plug things in shortly. Hope I have the wiring right.

The diagram looks very good. Mine are connected exact the same way and they're working fine.

In addition of what you have drawn, you probably need to ground panel frames somehow.

Surfpath · February 2013

Re: Panels going up

So they are mounted:

To recap: The panels are above my porch. My porch roof is as follows (top to bottom) Aluzinc metal roof then 2" hardwood purlins then 1" hardwood deck and then 6" hardwood rafters.
Here's the mounting system:

Rails

Galvanized Unistrut rails (two runs, each run 30 feet). The rail runs are bolted together (using slotted galvanized zinc with SS hardware)
8" Stainless hangar bolts to hold up the unistrut rail (3 bolts per each 10' run of unistrut).
Each bolt is mounted at the apex of the corrugated metal roof surface (ie. no 'valley' mounts)
Butyl rubber sealant was applied to the drill hole, the bolt threads, and the underside of the "bolt rubber." Heavy rains recently no leaks so far. Porch roof not a big leak risk issue. Easy to spot them if they occur.

Clamps

3.5" Stainless bolts screwed into galvanized zinc unistrut nuts
2.5" x 3" aluminum clamps (I took the L feet that came with the hangar bolts and cut the aluminum into flat clamps)
Nylon washers to isolate the stainless steel from the Aluminium clamps (these washers will be replaced with thicker nylon spacers)
Hardwood blocks for the end clamps

Grounding system:

One Aluminum "pass through" Lug attached to each panel (no lay-in lugs here)
Each lug is bolted to the panel with aluminum nuts and bolts.
One run of #10 AWG ground wire that connects the lugs on the panels (insulation "bared" at the lug)
The ground run will also connect to both rail runs (still have to do this - what do I use - steel lugs?)

Finally, an overall picture (note that the final wire connection has not been made. That's why you'll see some black 10AWG panel wire here and there):Attachment not found.

Surfpath · February 2013

Re: Panels going up

Here's a close up on an end clamp. The panels are about 4.5 inches off the roof.

Yes, you will notice microshading in the early morning or late afternoon (when I took this photo). The good thing is that between 9am and 4pm there is none.

And, I forgot, you will see that the aluminum panels are isolated from the zinc unistrut using aluminum pipe insulation tape.
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NorthGuy · February 2013

Re: Panels going up

I wouldn't use wooden blocks with clamps. Wood swells when it gets wet then shrinks when it dries. It is doing that mostly accross the fibers. With time, this may loosen the clamp.

Surfpath · February 2013

Re: Panels going up

NorthGuy wrote: »

I wouldn't use wooden blocks with clamps. Wood swells when it gets wet then shrinks when it dries. It is doing that mostly accross the fibers. With time, this may loosen the clamp.

Thanks for the reply. I agree that some shrink/swell could happen. Question: If I also use the same padded aluminum pipe insulation under the wood, would the resultant 'compression' in the clamp help to offset any shrinkage/expansion in the wood?
Basically...any alternate suggestions?

NorthGuy · February 2013

Re: Panels going up

Surfpath wrote: »

Thanks for the reply. I agree that some shrink/swell could happen. It's greenheart, but I can also use purpleheart which undergoes comparatively little volumetric shrinkage. Also, if I use the same pipe insulation under the wood, would the resultant compression in the clamp help to offset any minimal shrinkage/expansion in the wood?
Basically...any alternate suggestions?

I would use aluminum. You can get it in lots of different shapes at a local metal shop. Then you can cut it in pieces to match the width of the frame. It also will not rot.

The manufacturer of the clamps may have special spacers made for just this purpose.

Photowhit · February 2013

Re: Panels going up

I agree with that 'North Guy', aluminum should expand and contract with the frames, since you only need 4, I'd go ahead and buy the aluminum clamps made for this. I even have some if the panels are about 1.75" high (they are made for NingBo 170-180watt panels), just refund the shipping cost. I'll never use them. I recall they look like a squarded 'Z' with a bolt hole in the bottom, so they might work with taller panels.

Surfpath · February 2013

Re: Panels going up

Photowhit wrote: »

I agree with that 'North Guy', aluminum should expand and contract with the frames, since you only need 4, I'd go ahead and buy the aluminum clamps made for this. I even have some if the panels are about 1.75" high (they are made for NingBo 170-180watt panels), just refund the shipping cost. I'll never use them. I recall they look like a squarded 'Z' with a bolt hole in the bottom, so they might work with taller panels.

Hi Photowhit.
Thanks v.much for the offer. The Panels are 2"

(Newbie here) But, if the end clamp is aluminium and the strut it is attached to is galvanized zinc then would they not play well together? Maybe your type of clamp would avoid any galvanic issues.

I searched our very small hardware store and did not come up with any good ideas yet. In general, I have limited options. Just the basics are readily available (ie. PVC, elec. conduit., wood, nails, etc). Everything else takes > month and $$ to be shipped.

Surfpath · February 2013

Re: Panels going up

Surfpath wrote: »

I searched our very small hardware store and did not come up with any good ideas yet.

Wee update. I have found someone who might be able to craft these end clamps in aluminum. Hope not too $$.

OK, more photos, this time of the panel wire leads to the combiner box.

A few notes:

The wires from each series of panels (6 total) run in the electrical conduit that you see on the bottom right of the photo. This (5') short run of conduit, which goes from the panels to the combiner box, is not "capped off" at either end. Right now any water that gets in the end nearer the combiner box just drains out the end which is located under the 2nd series of solar panels. The conduit is there to tame and shade those PV wires.
You'll notice that the (yellow) ground also runs in this conduit (should it?). It peels off and enters the right hand side of the combiner box

In general: The NEC does not apply to me but I obviously want to make sure this installation is safe.
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westbranch · February 2013

Re: Panels going up

where have you put the Neg. wires?

Surfpath · February 2013

Re: Panels going up

westbranch wrote: »

where have you put the Neg. wires?

Ha ha. I can see how the red tape on the wire could confuse. They are there at the back row of the prewired combiner box. The red tape markers are temporary, used to identify the 3 pairs of wires (in series.)

Surfpath · February 2013

Re: Panels going up

Surfpath wrote: »

Ha ha. I can see how the red tape on the wire could confuse. They are there at the back row of the prewired combiner box. The red tape markers are temporary, used to identify the 3 pairs of wires (in series.)

Here's another view of the combiner box. Again, please ignore the red tape on the PV wires. Also, this is a prewired tyco box. The far right + and - connectors will not be used in this installation. That's why they are empty.

The main thing is the 'yellow' ground (Yes, I know yellow is not a traditional ground wire color, but that's OK here). Does that wire need its own conduit from the panels and rails, or can it run with the rest of the PV wires?
Thanks!
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Panels going up

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