A Forum run by Enthusiasts of MidNite Solar

General Category => Online Training sessions => Topic started by: lucky on December 25, 2013, 10:00:46 AM

Title: PV-shot
Post by: lucky on December 25, 2013, 10:00:46 AM
when i connect midnite with battery 48v with setting, and solar 125volt,
when i power on the solar breaker the analog meter will sudenly drop volt ,then goes up and down volt ,continously


amp
0000
batt
49.9
Title: Re: PV-shot
Post by: TomW on December 25, 2013, 10:41:04 AM
Quote from: Danish on December 25, 2013, 10:00:46 AM
when i connect midnite with battery 48v with setting, and solar 125volt,
when i power on the solar breaker the analog meter will sudenly drop volt ,then goes up and down volt ,continously


amp
0000
batt
49.9

Danish;

We are going to need a bit more information to help you out. This is a bit too vague to even guess.

Specific information on what "Midnite" is? The mymidnite site, Local App  or a Classic Controller?

Panel specifications, etc.

Where is this analog meter?

The Classic intermittently loads the PV source to find the power point which can cause the PV in volts to fluctuate.

Get back to us with a bit more detail and I am certain these guys can help  you sort it out.

Tom
Title: Re: PV-shot
Post by: lucky on December 25, 2013, 01:55:47 PM
input pv volt meter,fluctuate
300w mono
series connected 4 pannel
pv-125V(display on analog meter with out pv input breaker on)

pv DC voltmeter is installed before the DC input breaker
Title: Re: PV-shot
Post by: tecnodave on December 25, 2013, 03:11:12 PM
Danish,

Check that you may have a bad connection somewhere in your PV circuit. If there is a high resistance somewhere in the circuit the system will do exactly as you describe. The Classic will see the 125 volts and try to load the panels, when voltage drops then Classic will unload the panels. Possibly a loose connection somewhere, check tightness of wires on breaker, they will loosen sometimes. Other than that if you have an ammeter hook it into the PV circuit and watch when the voltage drops, you should see the ammeter rise in reading, if not then confirmed you have a bad connection. If no easy way to connect ammeter turn off PV breaker and hook ammeter positive to PV side of breaker and negative to Classic side of breaker.

Hope this helps......Merry Christmas.....Tecno
Title: Re: PV-shot
Post by: boB on December 25, 2013, 04:37:37 PM

Is this meter on the Classic or on the PC in the Local App ?

Merrry Christmas folks !

boB
Title: Re: PV-shot
Post by: TomW on December 25, 2013, 04:40:27 PM
boB;

Quote from: Danish on December 25, 2013, 01:55:47 PM

pv DC voltmeter is installed before the DC input breaker
Title: Re: PV-shot
Post by: lucky on December 30, 2013, 10:52:39 AM
ALL wire are connected tightly...........................
Title: Re: PV-shot
Post by: tecnodave on December 30, 2013, 05:10:33 PM
Danish,

It still sounds like a poor connection, when no current is drawn there will be voltage but when loaded voltage will be lost in the bad connection. If you do not have test equipment one way to isolate the problem would be to dummy load the panels with a light bulb, the standard incandescent light bulb will work on AC or DC. A good load would be a 300 to 500 watt quartz halogen work light however a single 100 watt bulb will load enough that you will be able to see the problem.  It will load the panels enough that you will see a bad connection as fluctuating voltage on the meter or flickering of the light bulb.  If the light is steady bright you will know that the problem is elsewhere.

On a complex system it is best to isolate the parts and test each unit individually. If you disconnect the panels from the controller and test with dummy load you will know which side the problem is on. It just might point to the problem. Try a few tests and post the results and I will answer, I have been a diagnostic electrician and engineer for 48 years so I will be able to guide you in a few simple steps to isolate the problem that you are having
Title: Re: PV-shot
Post by: lucky on December 31, 2013, 09:11:28 PM
i check througly pv input and batt terminal,
pv is fluctate when i connect pv with midnite,,,no load is connected......
one another thing is display on midnite screen

    .......OCP
Title: Re: PV-shot
Post by: Halfcrazy on January 01, 2014, 06:41:05 AM
If it will not charge at all and shows ocp all the time than it may have an issue. You will want to Email Mat@midnitesolar and let him know you have a Classic that constantly displays OCP. Give him as many details as you can about the system as well as the model and serial number of the classic.

Ryan
Title: Re: PV-shot
Post by: ClassicCrazy on January 01, 2014, 01:35:46 PM
I seem to remember I had a problem with the voltage fluctuating  and doing weird stuff and a newer firmware version fixed it. So check to make sure the firmware is up to date.