Very new to solar but started purchasing items, not sure of the final specs of the whole system.

[kromc5]

Almost complete I have two partial rows of 24 bifacials up and waiting for the replacements to finish.
Doing well with loads today with clear skies. Some more pics of the like new panels with minor blemishes I will be selling for
extremely overly inflated pricing. Amazing that some many shipments are damaged and completely destroyed pallets. I take lots of scrap to my local recycler but they refused the panels due to glass.

 

[Hedges]

Every time I see those polarized breakers used for PV strings, I object that they can't provide the protection they're supposed to: interrupt current backfed into a shorted PV string.

Are all strings being paralleled fed to a single group of breakers which are side-by side, and electrically ganged by that busbar? (i.e. the two busbars and their wires are not also connected together feeding a single MPPT)

I suggest sliding a pin through the handles so they are ganged.
That way, if one trips due to overcurrent (but can't interrupt the arc because current is flowing in reverse direction), it turns off the other poles which supply the current.

(I haven't confirmed the magnetic trip function will even trip with current flowing in reverse direction. But we know if opened it will not interrupt as high a current and voltage as in the intended direction.)

 

[kromc5]

Every time I see those polarized breakers used for PV strings, I object that they can't provide the protection they're supposed to: interrupt current backfed into a shorted PV string.

Are all strings being paralleled fed to a single group of breakers which are side-by side, and electrically ganged by that busbar? (i.e. the two busbars and their wires are not also connected together feeding a single MPPT)

I suggest sliding a pin through the handles so they are ganged.
That way, if one trips due to overcurrent (but can't interrupt the arc because current is flowing in reverse direction), it turns off the other poles which supply the current.

(I haven't confirmed the magnetic trip function will even trip with current flowing in reverse direction. But we know if opened it will not interrupt as high a current and voltage as in the intended direction.)

I would need to test that, the breakers feel like the have a very weak click to them. I wonder if one could even knock the others off or would it get stuck in the on position.

 

[Hedges]

Breakers are supposed to function even if someone ties the handle in "on" position.
Some assemblies are sold with up to 4 poles ganged. I have a similar Outback breaker with 6 ganged.
You could probably test tripping of a ganged group with 3x panels feeding through a single breaker, or whatever reaches the "trip" current. Less voltage is better when doing tests.

These breakers were UL (or equivalent) tested and certified to interrupt overloads, but only with current flowing in one direction.
I have never seen anything showing they actually function to protect a backfed PV string.

 

[kromc5]

Breakers are supposed to function even if someone ties the handle in "on" position.
Some assemblies are sold with up to 4 poles ganged. I have a similar Outback breaker with 6 ganged.
You could probably test tripping of a ganged group with 3x panels feeding through a single breaker, or whatever reaches the "trip" current. Less voltage is better when doing tests.

These breakers were UL (or equivalent) tested and certified to interrupt overloads, but only with current flowing in one direction.
I have never seen anything showing they actually function to protect a backfed PV string.

There last ground mounts are all 4s so the voltage will be around 195+ range.

 

[kromc5]

Never done hvac before, it was not the sheet metal work, removing the old system etc that was hard. It was the wiring and getting that correct. I finally got to run it today the mr cool 3-ton unit it keeping the house temperature at the correct level. Currently 82 out but we get well into the 90's. Only load is the 3 ton running.

 

[Hedges]

There last ground mounts are all 4s so the voltage will be around 195+ range.

I think that would be plenty to burn when opening from a short, reverse fed.

https://www.midnitesolar.com/pdfs/165_VDC_ETL_TEST_STORY.pdf

The breakers are rated 150V, for one pole. Two poles in series is how they make a 300V breaker. Note one has "+" on one end, other has "-" on same end, and wired to loop back. Alternatively, two breakers can interrupt negative and positive leads, advantage of completely disconnecting array. Maybe both on positive is better if negative is grounded, considering possible faults. Either way, have to be ganged or else one 150V breaker would see all 300V.

Product - MidNite Solar

MidNite Solar Product Page.

www.midnitesolar.com

Normally, if one breaker is opened, it sees Voc from its string and the other side might be at Vmp of the other strings. It only sees full Voc across it if other side at ground. That would be the case for a short, or prior to SCC capacitors charging.

My 6-gang 100V CBI (Outback) breaker, from before Midnight suggested they label the poles:

 

[kromc5]

Here's the lowest bill so far, guessing I did some work this month. March/April/May are usually the lowest months usage. Grid power is also better this year with only one time the neighborhood was without power.

 

[kromc5]

Went to lowes and got the conduit and decided to at least get the wires run and be ready for the replacements on the other row.
I used galvanized steel to connect all the panels for grounding. I wanted a simple way to do this and what I came up with. I have these on both sides of the panels.

 

[Hedges]

Inspected or not?
Steel straps and screws wouldn't comply with grounding requirements. Typically, stainless screws and copper wire is used, with something like a tinned clamp to hold the wire. One of the requirements was that removal of one panel wouldn't interrupt ground continuity for the rest.
Another scheme has clamps that bite in to aluminum rails providing contact. Then on the rails required ground connections.

 

[Nobodybusiness]

Never done hvac before, it was not the sheet metal work, removing the old system etc that was hard. It was the wiring and getting that correct. I finally got to run it today the mr cool 3-ton unit it keeping the house temperature at the correct level. Currently 82 out but we get well into the 90's. Only load is the 3 ton running.

Love my Mr Cool universal. Installed it few months ago with air handler.
Will never pay someone to do HVAC again.

You running the K9’s from Batrium?
Do you use a shunt breaker ?

 

[kromc5]

Inspected or not?
Steel straps and screws wouldn't comply with grounding requirements. Typically, stainless screws and copper wire is used, with something like a tinned clamp to hold the wire. One of the requirements was that removal of one panel wouldn't interrupt ground continuity for the rest.
Another scheme has clamps that bite in to aluminum rails providing contact. Then on the rails required ground connections.

I did find some ground lugs that are tapped on the sides or under and then use the bare copper. For the last few arrays I have been trying to use wood and anything else I had left over from other projects.

 

[kromc5]

Love my Mr Cool universal. Installed it few months ago with air handler.
Will never pay someone to do HVAC again.

You running the K9’s from Batrium?
Do you use a shunt breaker ?

They saved me a bunch with the hvac and mini split having the option to install myself. I'm using the watchmon 4 with shunt breakers.

 

[Hedges]

I did find some ground lugs that are tapped on the sides or under and then use the bare copper. For the last few arrays I have been trying to use wood and anything else I had left over from other projects.

I think something like this.

ALUMINUM LAY-IN LUG TIN PLATED #14 - #4 AWG STAINLESS STEEL SCREW

ALUMINUM LAY-IN LUG, TIN PLATED, #14 - #4 AWG, STAINLESS STEEL SCREW

www.elecdirect.com

Lay-In Lugs | Solar Grounding Lugs | ElecDirect

ElecDirect offers copper and aluminum lay-in lugs for solar grounding. Shop a selection of wire management and electrical connector solutions online!

www.elecdirect.com

 

[kromc5]

I think something like this.

ALUMINUM LAY-IN LUG TIN PLATED #14 - #4 AWG STAINLESS STEEL SCREW

ALUMINUM LAY-IN LUG, TIN PLATED, #14 - #4 AWG, STAINLESS STEEL SCREW

www.elecdirect.com

Lay-In Lugs | Solar Grounding Lugs | ElecDirect

ElecDirect offers copper and aluminum lay-in lugs for solar grounding. Shop a selection of wire management and electrical connector solutions online!

www.elecdirect.com

That is what I found, I just had those metal straps left over and went to town. I can work on getting those and installed. So far Crazy Eddies fly by night solar inspections signed off on everything. /j

 

[kromc5]

990ft of 4awg came in temp rating is 500f I want to be prepared for any large solar eruptions hitting the planet. Guess the correct cable type to win a one-week vacation at camp solar wonderful were we work sunup to sundown on solar.

 

[kromc5]

Was not able to rent the trencher till Monday, I pulled the wires into the house first then through the conduit. Went on and took the time to get them run and cut. The jacket that gives it the 500f rating is very flexible but has to be pulled straight from the spool or wants to bind up terribly. Cut larger holes in the spool and mounted it on the pallet forks. Total length for each wire is 92ft from panels to scc.

 

[kromc5]

Trenching complete and finishing the conduit.

 

[kromc5]

Got most of the work done, the other two sccs should be here tomorrow. Not heard back from santan and will need to follow up.
Just finished moving the dirt back into the trench, close up the of the cable.

 

[kromc5]

SCCs are out for delivery, two more midnite surge protectors came in.