midnite classic creating 117V at pv input

[australsolarier]

this is what happened last weekend. i received this new 48v/400ah lifepo4 battery. i temporarily connect the midnite classic to 3x 24v panels in series leaning on the wall. they charged up the battery and the midnite classic went to float. having confirmed that the system all nicely worked, i disconnected the 3 solar panels.
here we come to the interesting fact:
the input voltage remained at 117/118v. after a couple of hours i thought "holy duly midnite really installs super quality caps".  however i also noticed that the midnite used 0.4a. and the temps were quite warm for doing nothing: 44.2 and 48.4 degrees. also periodically the fan in that midnite came on. whereas the first midnite classic connected to the  12v system worked at 500watts and the temps were lower.
note:  the input was not connected to anything. so i disconnected the battery and reconnected. the input voltage went to 39volts, and whizbang jr shows the normal 0.1a use. and stayed like this the last two days.
i vaguely remember somebody mentioning this very same fact on the forum here.
to me it looks like the midnite was running in reverse. however i did not check if it could be used as a stepup switchmode device. i suspect the current would have not been very big. but it was doing something to warm up to trigger the fan.
just wondering if midnite is aware of this.

greetings urs

[ClassicCrazy]

Were you reading the voltages on a meter or on the display of the Classic - or Local Status app ?
Larry

[australsolarier]

i was reading them first on the midnite classic display, then with the voltmeter, the voltages corresponded. i was tempted to shorten it out, but refrained from that impulse, just in case.
like i wrote, there were absolutely no solar panels connected. when it went to float, the input voltage went up to 118v or the like. there is nothing connected to battery. so no usage. after i disconnected the panels the voltage just stayed up there for hours until i disconnected the midnite from the battery. reason says the midnite classic was reversing.
i imagine it is not a problem as such, but still an interesting fact.

[zoneblue]

Weird is what id call it. Theres no way that a classic with no input connected should be in float. Are you sure? Try to take a photo of the MNGP when it occurs.

It is however normal for some voltage to be present on the input when not charging, thats just the way the buck oncverter works.

[dgd]

Hi,

I'd strongly recommend you turn everything off and sort out all the wiring before you end up blowing something up (eg the Classic) or starting a fire somewhere.
There is just no way the Classic can go into Float, and as expected the input voltage rise, without there being any PVs connected.

dgd

[australsolarier]

hello you guys

ok, just to make it clear, absolutely clear:

i hooked up the array (3x 24v panels.
the midnite went first to bulk charging
then absorption
then, the battery was fully charged
THEN the midnite went to float (arrays still connected)

however as the battery was now full:
the voltage went about to something like 118v (because the midnite was in float and no usage of the battery, no connection, please note again, because the inverter has not  arrived yet, note is not ordered yet, nowhere anywhere close to my midnite classic!!!!!!
i turn off the breaker with the temporary array
then, EVERYBODY pleas take note!!!!   disconnected the solar panels physically. ok, so no physical connection at the input anymore
so the only connection was to the lifepo4 battery, and the dc solar breaker and whizbang jr etc.

again please read correctly here:
the voltage stayed up at 118v
the whizbang jr showed using ( to make it clear for everybody, electricity flowing from the battery to the midnite classic) 0.4 amps. now, resting it only uses 0.1.
the temperature reading showed 44.2 and 48.4 degrees celsius. the fan (inside the midnite classic, to be precise) came on periodically.

for the fellow with the advice about checking the wiring:
please note : AFTER DISCONNECTING THE MIDNITE CLASSIC FROM THE BATTERY, THE MIDNITE TURNED OFF, ZILCH, NADA, ZERO, I MEAN ABSOLUTELY NOTHING ON THE DISPLAY.
turned the midnite classic breaker back on to reconnect to the battery. now, input voltage showed 38.9 volts
whizbang jr 0.1amps, the temp reduced down 35.5/42.2 degrees celsius after a while, probably more later on. (and no solar panels connected, if anybody should be wondering)
it seemed to me the midnite classic missed going into resting mode.

ok to repeat, the only thing that was connected, was the battery. and take my word, the polarisation is connected correctly.

for the blowup theory fellow:  i reconnected today for a short while to the solar array, again 3 panels at 24 volt nominally, polarization  correct, it charged in bulk mode, however did not wait for float. the reason is,  as mentioned before, there is no use of the battery and i do not like to keep the voltage in the lifepo4 up in absorption voltage.
programmed to specs of the lifepo4 : absorb: 56v, float53.6  (the lifepo4 battery is 48v and 400ah, just in case somebody is wondering about that)

this is probably for the midnite classic people to look into.

now if anybody is interested i can give them my mymidnite username and password. just in case there is still somebody out there thinking i should check the wiring.

whats more, i vaguely remember somebody mentioning a similar case on this forum as well.

i hope i cleared some uncertainties for the sceptics

greetings urs

[Westbranch]

please don't forget that the Classic is powered by the battery, not solar, so that small amount is to be expected...

the whizbang jr showed using ( to make it clear for everybody, electricity flowing from the battery to the midnite classic) 0.4 amps. now, resting it only uses 0.1.

[australsolarier]

westbranch!

on resting the midnite classic uses 0.1A according to the whizbang jr

(as i described above)

however, in the case described above, the whizbang showed 0.4A and as described above, nothing was connected to use that kind of current. so, i mean, to make it quite plain and simple and  i hope most of the readers understand that, this current must have been used up inside the midnite classic. and warmed up the fets and all the things inside the midnite classic  to trigger the fan.
and even if there was some parasitic current, say a spider or a fly connecting the battery terminals, or sawdust, the 0.4 A should not warm up the midnite classic. besides that current would have come from the battery.
to me it seems logical, if there is no electricity going into the midnite classic none can come out. ( do i have to describe that more clearly??) as a logical progression that current warming up the midnite classic came out of the battery. so besides keeping all the circuits running inside the midnite classic on standby it was doing some other mysterious action. now this mysterious unknown action, that is what i am wondering about.
westbranch, i am aware of all those facts. i have two midnite classics. they are being watched all the time when i am anywhere near the computer or the shed. or on the team viewer or mymidnite page when at work.

now i am aware that this is a weird case. i in no way want to fault the midnite classic engineers. all i want is letting them know of this fact. and i am not too keen to replicate it. i am quite happy having a working midnite classic. so it might not do that symptom when panels keep connected. like in the evening when it goes to sleep. maybe it does not like the panels being disconnected. however when i disconnected the pv, the current was 0.

[WizBandit]

I think the latest firmware may have fixed this...

[zoneblue]

Try to be a bit patient with us. Most of the folk on the forum are volunteers, but between us we do have decades of expereince with RE. It is possible there is a fault with your controller, but it will help to rule out any system issues, which is why were asking for clarification a bit.

Firstly what firmware are you running?

however as the battery was now full:the voltage went about to something like 118v

Which voltage? And how did you measure it?

i turn off the breaker with the temporary array
then, EVERYBODY pleas take note!!!!   disconnected the solar panels physically. ok, so no physical connection at the input anymore

Its not a faulty breaker or anything? How did you disconnect the array, esp given its a fairly high (shockable) Voc?

again please read correctly here:
the voltage stayed up at 118v
the whizbang jr showed using ( to make it clear for everybody, electricity flowing from the battery to the midnite classic) 0.4 amps. now, resting it only uses 0.1.
the temperature reading showed 44.2 and 48.4 degrees celsius. the fan (inside the midnite classic, to be precise) came on periodically.

Please can you clarify if the controller is remains in float, when you disconnect the array.
The classic only uses that low few watts when it is truly resting. The non resting non charging draw is somewhere up in the 15W area. Whats your ambient temp? Classics run warm in float, its just how they work.

If you remain confident that there is an issue with your unit, you are adivsed to open a support ticket, to make sure that tech support gets to look at this. They sometimes dont see things on teh forum for a day or two.

[RossW]

If you remain confident that there is an issue with your unit, you are adivsed to open a support ticket, to make sure that tech support gets to look at this. They sometimes dont see things on teh forum for a day or two.

The description of the "fault" is absolutely identical to that which Steve reported oh, 8, perhaps 12 months ago.
He made videos of it. Everyone seemed to think he was bonkers too.... yet it was demonstrable and repeatable.
And now we have someone unrelated, on the opposite side of the world, seeing the same thing.

Inneresting, 'aint it?

May be an "unusual" situation, but it isn't "unique". australsolarier may have identified something you've not seen, and is not "supposed" to happen, but he's not bonkers. Not if someone else got the same thing almost a year back!

[Halfcrazy]

I believe Jim is right, The latest firmware should put a 90 second time out on that if it isnt making real power.

[zoneblue]

Ross, noone is calling anyone bonkers. Is this the thread youre talking about:

http://kb1uas.com/mnsforum/index.php?topic=2280.msg22674#msg22674

[australsolarier]

zoneblue,
i am sure you are meaning well. however, if the sun panels are removed, it does not matter whether the breaker is working, you can put bullets into it, dip it in acid, smash it with a hammer: IT IS TOTALLY IRRELEVANT. as for your other questions they are amply answered if you only read the whole thread. i cannot  possibly get much more implicit.

for the other folks:

thanks for taking me serious. i am not actually saying the midnite classic is faulty.
bye the way, i noticed when you turn off the breaker to the solar panels, the classic goes into some intermediate state. some high pitched sound i can just about hear comes from the midnite classic. and again a higher voltage than the battery at the input. and higher current use (current from the battery into the classic midnite) on the whizzbang.  but then a few seconds later it drops into resting. so maybe the midnite forgot to get into resting mode. i am sure there is probably a LOGICAL explanation for it, but it is way beyond my knowledge. i am pretty sure the midnite classic engineers probably already know why.
firmware is 1923/1839. i was on planning to update the firmware. however. however. the laptop is windows 10. so i was not going to waste 3 hours then find out somewhere along the 30 step update procedure, that it does not work with windows10. so i will wait till that promised easier update procedure is reality.

so thanks again for all the folk reading the thread and actually taking me seriously of  what i was describing

all the best to all of you and lots of sun shine

greetings urs

[Westbranch]

From what others have said W10 is a GO, way easier than W7 or W8...

don't have experience as I am on W7 still