Absorb cycle is too short

[Westbranch]

I am thinking the topic should have included " CC enter Absorb at < 1 Amp"

here is a screen shot including this morning.  the first 3 days have about 3 hrs run time on the gen, ending about noon or so... that is when the PV kicks in  100%

Note on day 3 the early entry to Absorb just after gen shut down,..
Yesterday it entered Absorb just when the system should have started full output, but stopped at ~7 Amps.

Today it entered Absorb at  1 Amp input and drops to .3Amps... at ~ 25 Volts  ?? then goes to the max Absorb voltage...29.3V

We won't be headed back out till Sunday when I will do a longer run  on the gen set.

My question for  boB or ?  is

" What are the parameters that the Classic uses to enter Absorb"  ...

[Westbranch]

well....I think I have zeroed in on the source of the puzzle....high resistance...

We are back at the cabin tonight  to gen boost the battery and for the next 3 days.....

I went down to do some comparative V readings at the battery and inside the E panel. 
Was going to do from the Classic but will do that tomorrow....

Whoa!  Why are those RED wires BLACK???

The 2 Pos wires that attach to the small POS bussbar, one from the battery post of the main CB , the other from the PV CB, are both charred ~2 inches back from the bussbar....  That should create some resistance to current flow, eh ??

Checked the screw tightness and both hard tight, loosened them and re-tightened and found that the one for the PV now read ~2.0 V low.  Loosened and tightened and the voltage jumped around ... stopped when it was within .2V of my DVMM of battery V.

Question now  is WHY?   when they were both tight?

[dgd]

Can you post a pic of the burnt wires and general area in epanel?

Dgd

[Westbranch]

it will have to wait till the morning ....now I have to suss out how to shrink 1.5 mb to kb to be sent in this bb's rules?

[Westbranch]

attempting post of pics, here's hoping


It worked,  I used Image resizer powertoy for W7

ADD:   I didthink about an IR temp tester last night when I saw the charring...hind sight is  20/20.. I wanted to do that last night but IR meter is 180 miles away... have to get one for here.

This morning the V readings are 2.3V apart.  I have to shut it down and steal some wiring from my 2 nd Epanel, that's waiting to be installed...

[Resthome]

I bought a toque screwdriver for just this reason. I believe Midnite provides the torque spec in their manuals. Not sure about the e-panel manuals as I am not using them. The spec for the breaker always seemed high an I did not want to break them so I believe I stepped it down a setting.

[Westbranch]

I sure wish I had one of those when I had to undo that screw today, so I could know if they used an impact driver or like device.  I really had to apply a lot of torque!  Used my largest screw driver so as not to damage the slot after trying a slightly smaller one...!!

[ClassicCrazy]

What are the rated specs of that breaker and the  e panel ?  Sure seems weird that it melted like that under rated amperage . Almost seems like something else had to be going on - either oxidized wires where it was screwed in or some kind of nick in the wire insulation somwhere ?   I would also replace that whole junction bar too - that one is messed up .

Larry 

[Westbranch]

Yup, I robbed my 'parts' Epane l of the buss bar and its factory cable and fab'ed a new line to the PV CB's. .. I looked for obvious damage but none seen so if it was in the first 2+- incjhes they were all fractured by the heat.
I am pretty sure it was a bad connection that is the fault.  I really clinched down on the new wires,   and will re-torque in the AM to allow for 'flow'..

[ClassicCrazy]

what is the amp rating of that breaker ?

[dgd]

That damage looks too severe for just a screw down connection that was not torqued down.
Both wires are burnt so did you forget to torque both of them?
I have seen Epanels where the solar inputs were not re-torqued after waiting a day for the copper wire to relax and weeks later when I checked they seemed loose yet there was no severe burning of cables that you evidently have.

Were the cable ends folded over and perhaps soldered so that the cable end more fills the terminal hole?

I would be looking for other reasons to cause such damage. Those cables could just be too light for the current or if they are not multi strand hundreds of cores but few strands then they may have worked hardened strands that have fractured or split. This can cause arcing and burnt cables.
So most of the damage to the terminal block and cables may be secondary heat damage with the real reason for the fault somewhere else.
That breaker wiring looks interesting, is that the PV input breaker?  Never liked those high current wire push in DC breakers, much prefer the carling non polarised types with decent  bolt lug with both nut and lock washer - then the cable can be properly terminated in a solid copper ring lug that is deformed crushed onto the cable and tightened up once only, none of this copper creep nonsense

Just IMHO

Dgd

[ClassicCrazy]

I was just looking at the epanel installation instructions.  Some of them show that positive bus bar that melted - other schematics don't .

I use the Mini DC panels that I wire up myself according to supplied schematic . On those the terminal stud on the inverter breaker is used as the positive dc connection - this stud is big and can accept ring terminals that have been crimped on the cables . Then there is a nut that you can use a socket on to really get some torque on and get tight.

I wonder if you get some longer wires if you can do the same sort of arrangement with your epanel and eliminate that positive terminal strip ?

And yes dgd - I switched from those din rail to other breaker with 1/4 studs - much easier to wire and torque up tight than the din breakers . I had to switch since I needed 100 amp breaker because the  63 amp one was  too small and tripping off sometimes.

Larry

[Westbranch]

what is the amp rating of that breaker ?

It is 60A


Were the cable ends folded over and perhaps soldered so that the cable end more fills the terminal hole

No, just bare wire, straight in..

Both wires are burnt so did you forget to torque both of them?

That is possible.
The black on the one to the 60A CB stops parallel to the top of the buss bar, the charring of the insulation is just at the buss ... 
The one to the 175A Inverter breaker post, has its insulation fractured well away from the buss connection.

On those the terminal stud on the inverter breaker is used as the positive dc connection

Yes, that is how mine is too.

Hope these pics show what we discussed...

[ClassicCrazy]

I suppose if they were never tightened at all that might happen ?

So why not eliminate that buss bar all together and just hook up directly ?

Larry

[Westbranch]

I suppose if they were never tightened at all that might happen ?

So why not eliminate that buss bar all together and just hook up directly ?

Larry

They might have been under-torqued, but functioned normally for  2 years...  the high amperage brought it to the fore....

I guess it could be done but there must be a reason they (MN) have it in all their E-panels... so I used it.