Hello, I received my first midnite solar classic and went thru the instructions included and website. I used the calculator to verify the unit will support my panels before ordering. I have used other charge controllers in the past with no problem but they were voltage specific. I do not want to ruin the unit. Here is the question: If I connect the panels to the charge controller (safely with breaker and wiring completed without sunlight) - the unit will not need programming before connection??? I've never had a controller that needs programming such as choosing 12 Volt, etc. After it is connected to the solar input it will turn on and I can choose the output voltage via the menus or wizard and the unit will not fry? It will accept any acceptable voltage, etc from the panels and turn on?
Almost.
Connect the charge controller (Classic) to the BATTERIES first. It will detect the battery voltage and roughly configure itself in a couple minutes, you may need to press some buttons to accept defaults. You will likely want to tweak some of the settings to be a proper match for your batteries.
AFTER the controller is booted up from the batteries, then you may safely connect the PV to the controller, and it will begin operation - provided you don't exceed the voltage restrictions & the sun is out.
Generally, all versatile MPPT controllers require battery connection first to boot, and then after a minute, the solar may be connected.
If this was a new Classic, never been hooked up, then it SHOULD ask you to verify your system battery voltage i.e. 12V, 24V, 48V BUT it should guess it correctly unless your batteries are weird.
If it did NOT come up this way, with the first time setup screens, then we screwed up.
You can bring this screen up but turning the power OFF then ON then, when you see the MidNite Logo, press and hold down the LEFT and RIGHT arrow keys until the setup screen shows up and follow the menu.
You can connect the input at any time. You should have a volt-meter handy if you want to verify your PV voltage first.
boB
Thank you guys!!! My confidence is back. You are most appreciated! Also, on a less important note - I never could understand the physics about using (exaggeration here) 3 ought wire and then going thru little switches and breakers, etc. The current can hold up over the short distance but large wires over longer distances are more critical??? Anywho - if anyone has time to explain, it would be enlightening. Probably the wrong forum area. Thanks again.
Quote from: blueskies on May 27, 2019, 08:13:21 AM
Thank you guys!!! My confidence is back. You are most appreciated! Also, on a less important note - I never could understand the physics about using (exaggeration here) 3 ought wire and then going thru little switches and breakers, etc. The current can hold up over the short distance but large wires over longer distances are more critical??? Anywho - if anyone has time to explain, it would be enlightening. Probably the wrong forum area. Thanks again.
There are few things to consider when sizing wires correctly
distance
voltage
current
Larger wire has less resistance
There are charts and calculators for the resistance of wire called wire loss calculators .
You size the breakers to the maximum rated safe power for a wire.
example
12 gauge wire is 20 amps
10 gauge is 30 amps
6 gauge wire 60 amps
For lower voltage to carry more power you need very large thick wire - like for an inverter.
My 24v 3500watt inverter is specified to have 0000 wire - or also called 4/0
So if you have higher voltage you can use smaller wire and carry same amount of power
You need to learn Ohms Law
Power in watts = voltage x current ( amps )
example
12v x 1 amp = 12 watts
120 v x 1 amp = 120 watts
So advantage to put more solar PV in series and make higher voltage is that you can use smaller wire to carry more watts with less voltage drop over distance.
All these things are considered when you design solar system.
Not sure if this answers your questions - lots of good videos on youtube to help understand .
Larry
Yeah, 3-000 wire is a bit large for this type of stuff. Usually anyway.
boB