breaker problem

[mat]

Hi there,

My setup (1500w pv, a Kid, 235amp/48v battery bank) has been running quite well for nearly 2 years now.
About 2 weeks ago i did my first firmware update (1810).
Since, about 2 mornings out of 3, i find the midnite 30amp breaker between Kid and batteries OFF...
It apparently happens at sunrise (i just guess, i never stayed all night long to check, but at night it's still ON).
I tried yesterday to set anti-click sensitivity to 8,5 instead of 8, still the same...

Any advice ?

Thanks

Mat

Edit :
About a week ago i also lowered the max amps out at 28 amps. No change

Also, this breaker has never tripped in nearly 2 years...

[BobWhite]

Sounds like you have a loose connection  between the battery and the charge controller, it doesn't take much to cause heat and trip the breaker.
Walt

[mat]

Ok, as batteries posts are tight, i'll open the Kid tomorrow to check that. Let's hope it's just that.
What i don't understand is why it doesn't trip when charging 20amps+ ?

[BobWhite]

hi Mat,
what is it that you have for a breaker? I would also consider the connections at the breaker! That's were most of my problems begin. ( poor crimes on ring terminals or lugs) I'm just thinking outloud.
Walt

[Vic]

Hi there,

My setup (1500w pv, a Kid, 235amp/48v battery bank) has been running quite well for nearly 2 years now.
About 2 weeks ago i did my first firmware update (1810).
Since, about 2 mornings out of 3, i find the midnite 30amp breaker between Kid and batteries OFF...
It apparently happens at sunrise (i just guess, i never stayed all night long to check, but at night it's still ON).
I tried yesterday to set anti-click sensitivity to 8,5 instead of 8, still the same...

Any advice ?

Thanks

Mat

Edit :
About a week ago i also lowered the max amps out at 28 amps. No change

Also, this breaker has never tripped in nearly 2 years...

Hi mat,

So,  you did load FW 1811 into the KID?

It is stated that 1811 FW has some changes to the MPPT Tracking.

Assume that you have been using Solar Mode.  You might try one of the Legacy Modes,  to see if that changes anything.

As BobWhite mentioned,  a loose connection on that output breaker could cause a breaker trip,  due to heating.  Please do carefully check all of the electrical connections in your system.  Connections,  especially those that use a screw type compression connection can loosen,  over a period of time.

Although,  it DOES seem quite likely that the FW Update is likely associated with this breaker trip.

On the other hand,  seems that your PVs would not be able to output much over 25 Amps with the battery at about 48 volts.

In the early morning,  what do you believe the battery voltage to be?
What are the ambient temperatures,  when you guess that the breaker trips?

Don't suppose that there are any reflections from water or snow that might increase the PV output dramatically ...

Enough for now.   Thanks for any added info.   Vic

[mat]

Hi,
Sorry, i've been busy last 2 days...
Thanks for your tips.
So, 2 nights ago, breaker (well... A Midnite dc 30amps breaker is all i know. Are there different models and how to check that ?) tripped probably at sunset as it was off when i checked about 9pm...
Next morning was ok, this morning also...
Ambient temps here in Sarawak, Borneo are quite high in daytime (30/35c, sometimes up to 40c)), less nightime (25/28c).
We are just next to the sea and water reflection could happen but... As panels are abive sea level nearly flat mounted... I don't know if that's a possibility...
Batts usually down to 49 something in mornings, we are a bit hard on them these days, it's the time of the year that our little homestay is open. Then in rainy season they will be cycled much less for 6 months.
They usually hit absorb around 11/12 o'clock and are full nearly every day.

This afternoon i changed the wires from Kid to batts, something i planned to do anyway, previous wires were not too big even if they always performed well and never heated.
Wires were clean and connections tight everywhere (kid, breaker and batts)...

So... I'll tell you in a few days if this happen again...

If yes, should i go back to a previous firmware (and how ?). Oh yes, the 1811 is loaded in the kid.

Wait and see i guess.

Mat

[Vic]

Hi mat,

Thanks for the added info.

There are two basic of MidNite DC breakers.  Probably the most common one is the MNEPV.  This is called a DIN Rail breaker  --  it slides,  or really,  clips onto a horizontal metal rail.  It uses compression,  screw terminals to make electrical connections from the wires,  to the breaker.

The other type is the MNEDC,  which mounts with two screws on the front of the breaker,  and has electrical connections via threaded studs on the rear of the breaker.

Do you have a spare 30-ish amp breaker that you could substitute for the one that is tripping?   You would not want to substitute a breaker that has a rating that is much higher than the 30 amp breaker that you have been using  --  because the breaker might be too large for the size of the cable that connects the KID to the battery.

Cable connections to screw compression terminals really need to be quite tight,  but if you saw no discoloration whatsoever where the cables connect to the breaker on the output of the KID,  then probably there was not excessive heating at those two connection points (am kind of assuming that you are using the MidNite DIN breaker,  with screw terminals).

If you continue to see this breaker tripping,  and you do not have a different DC breaker to substitute,  you might try using Legacy P&O,  or perhaps Legacy O&P Mode in the KID.

Several years ago,  there was one or,  perhaps two reports of MNEPV breakers tripping at a current that was below its marked amp Rating.     Have heard nothing at all since.   There may be a very small chance that this could possibly be a cause.   BUT,  again have only seen one (or perhaps two) references to this on this Forum ...

And thanks for confirming the version of FW in your KID  --  1811.
If reverting to a previous FW version is easy for you,  you might want to try this.

Please DO let us know how the system performs,  and any further observations.
Good Luck,    Vic

[CDN-VT]

Mr MAT
Your breakers look like one of these ?
https://www.google.com/search?q=ATC+breakers&biw=1280&bih=654&source=lnms&tbm=isch&sa=X&ved=0ahUKEwis8PuiwuXOAhVH4WMKHWP_BpkQ_AUIBygC

VT
I have had a few DUDS , they are not the greatest till I bought the OCB style

Edit add since MAT did a factory restore .
The breakers I purchased had a few bad batches & they pre popped Or lack of continuity..
I dropped this junk style & used  aircraft style (used becase they are timed out ) ..

Saying Just !

VT

[mat]

Hi,
Ok for breakers types. Mine is the Din rail one. Like this :
https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcQP0Jv9_o70kAYvLaEUqV6YtU_0JzPKuj94ed8X-scOH59tIGtT

I tried a few times Legacy O&P, and always came back to Solar as i have better watts with it 80% of the time.

No tripping this morning...

I have another 30amp, same kind, for my first inverter (1500w).

I'll try to swap them if tripping happen again.

Thanks

[Halfcrazy]

If it trips again i would roll back to the firmware you had prior to this one. I suspect now that this may be a odd bug that a few are seeing. I will work with engineering today on this

[mat]

Ok, but how to go back to the previous firmware

Thanks

[mat]

I just saw this old thread that i never noticed :
http://kb1uas.com/mnsforum/index.php?topic=1982.0

Same problem apparently...
A
Still, i'm not sure which firmware i had before (1722 ? 1740 ) and how to get it back...

[TomW]

Not sure if this is even true, or if it would apply here:

When we were rewiring this ~100 year old house replacing knob and tube wiring, our electrician told me breakers were only rated for a limited number of over current trips? The number he quoted was 3 or 5? I cannot remember for sure but it surprised me that it was so low? Cover your Arse for manufacturers or a real concern?

Just tossing it on the wall to see what sticks.

Tom

[CDN-VT]

I heard that also Tom .
I had a machine that would eat a breaker every two years .
That took me a few years to figure out that it was making the breakers fail when they got weak .

VT

[mat]

So...
Today, after changing wires 2 days ago, 2 days without breaker tripping...

But...
Much worse now...
This morning, while bulk charging, my Kid stopped... Completely... No screen, nothing, no internal fuses blown, no way to start it again...

So i'm going to start another thread to explain all this in details...

..pfffff.....

Mat