No PV IN voltage passing through DC breaker

[Mechanicalbird]

hi I’m wiring a new array. Can someone please help me with an issue I’m having? I have voltage from the combiner box in the shed to the PV+ IN breaker before my classic, but no voltage is present on the other terminal of the breaker. Classic is showing no voltage. I have the + side of the breaker going to the PV panels. Is that correct? Thank you.

[Mechanicalbird]

It’s a 300v 30A Midnite breaker. Double pole.

[Resthome]

hi I’m wiring a new array. Can someone please help me with an issue I’m having? I have voltage from the combiner box in the shed to the PV+ IN breaker before my classic, but no voltage is present on the other terminal of the breaker. Classic is showing no voltage. I have the + side of the breaker going to the PV panels. Is that correct? Thank you.

Define what you mean by other terminal. And give us the model number of that breaker.

[Vic]

THE Manual, pg.  7:

http://www.midnitesolar.com/pdfs/MNPV2-3-4-6_manual.pdf

Vic

[Westbranch]

As is John a bit confused, I am too, can you please advise, and supply a drawing of same description, of where you are making a contact to the negative part of the circuit.

you can even refer to any of the MN wiring diagrams and post a link so we can understand said description.  use the simplest one you can find.  IIRC the ones for the Kid are the cleanest.

tks

[WizBandit]

What is the voltage at the array?  Sounds like you may have blown out the Classic's transistors.
The Classic IN should read 2/3rd battery voltage with the PV wires disconnected.
Either the PV IN is shorted or you have the polarity reversed.

hi I’m wiring a new array. Can someone please help me with an issue I’m having? I have voltage from the combiner box in the shed to the PV+ IN breaker before my classic, but no voltage is present on the other terminal of the breaker. Classic is showing no voltage. I have the + side of the breaker going to the PV panels. Is that correct? Thank you.

[CDN-VT]

hi I’m wiring a new array. Can someone please help me with an issue I’m having? I have voltage from the combiner box in the shed to the PV+ IN breaker before my classic, but no voltage is present on the other terminal of the breaker. Classic is showing no voltage. I have the + side of the breaker going to the PV panels. Is that correct? Thank you.

Define what you mean by other terminal. And give us the model number of that breaker.

Do you have the copper bottom bridges installed ? IF NOT , shut off all befor hooking up , or do it at night as well .

VT

[Resthome]

hi I’m wiring a new array. Can someone please help me with an issue I’m having? I have voltage from the combiner box in the shed to the PV+ IN breaker before my classic, but no voltage is present on the other terminal of the breaker. Classic is showing no voltage. I have the + side of the breaker going to the PV panels. Is that correct? Thank you.

Define what you mean by other terminal. And give us the model number of that breaker.

Do you have the copper bottom bridges installed ? IF NOT , shut off all befor hooking up , or do it at night as well .

VT

That would be my guess also.

[Mechanicalbird]

Thanks guys for the replies. So it sounds like you suspect the Classic 250 which I was really hoping wasn't the case.

This is actually a second array that I added a couple of months ago. It was working fine before, but I discovered I had all of my Midnite breakers hooked up the wrong way. I wasn't familiar with the + and - on the breakers. Anyway, I ended up burning up a breaker to my charge controller. I rewired all breakers correctly, I think, and now I no PV IN voltage to my second Classic 250. I guess I could have blown the Classic's transistor when I was rewiring the breakers though I did have the panels shut down when working.

I measure 148V IN at the breaker before the Classic, which is normal, but no voltage reading on the Classic itself. When I turn on the breaker there is no voltage present.

[Vic]

But,  Mechanical ..,

DID you confirm that the wiring for the 300 VDC MNEPV breakers (at 300 V,  they MUST be MNEPVs) ARE wired correctly,  as noted in that Manual Link? ?? ...    !

Sometimes,  in these Threads we DO get nested down with questions,  UNANSWERED.

The second thought here,  was that perhaps,  in error,  that the Classic CC was NOT powered down when the PV rewiring was done.   This could easily damage the CC (kind of like changing one's vehicle engine oil,  with the engine running !)

FWIW,   Vic

[dgd]

Thanks guys for the replies. So it sounds like you suspect the Classic 250 which I was really hoping wasn't the case.
...
I measure 148V IN at the breaker before the Classic, which is normal, but no voltage reading on the Classic itself. When I turn on the breaker there is no voltage present.

So you have done all the obvious tests? such as trying a different breaker? or not using a breaker and just connecting the pv array wires directly to the Classics PV in connectors?
FYI I have found the Classics to be quite robust and connecting or disconnecting either a pv array or battery when the Classic is power on does rarely cause any problem. I have seen a battery fuze blow disconnecting the battery bank from Classic yet the Classic stays power up and supplies current from PV array to inverter.
A few photos of your breaker and wiring would be useful
dgd

[Vic]

Hi dgd,

THE killer for most  ** EDIT  (Buck type)  **  MPPT CCs,  is shorting the PV input + to the --  terminal.   This almost always makes toast out of the FETs,   as I read it.   Thankfully,  we have no direct experience with this.

VT,  thanks for the correction,   so,    you are saying that it is OK to change the oil in my vehicles with the engine running,   and for CCs ...

FWIW,   Vic

[CDN-VT]

Back to this Breaker CC post , As I read it twice now , it was working
No power out of the breaker ?? & no display on the classic

Many replys but 3 info from the OP

This is actually a second array that I added a couple of months ago. It was working fine before, but I discovered I had all of my Midnite breakers hooked up the wrong way. I wasn't familiar with the + and - on the breakers. Anyway, I ended up burning up a breaker to my charge controller. I rewired all breakers correctly, I think, and now I no PV IN voltage to my second Classic 250. I guess I could have blown the Classic's transistor when I was rewiring the breakers though I did have the panels shut down when working.

I measure 148V IN at the breaker before the Classic, which is normal, but no voltage reading on the Classic itself. When I turn on the breaker there is no voltage present.

Id say you have toasted more than one breaker ,if there is no voltage out of breaker !

VT

[Vic]

Hi VT,

OH !!,    You were kidding,    OK   thanks,   kinna though that you might have been.  Analogies are seldom perfect   ...

Wizbandit  had a good point  --  if the input terminal of the Classic reads 0.00 V with nothing connected to the PV input  terminal,  and a 12 V or higher voltage battery connected to the Classic's output,   then   the FETs are probably toasted.

BUT,  I am no expert.   FWIW,    Vic

[CDN-VT]

Could be ,
Lack of reply info & if a DVM is being used ?