diy solar

diy solar

I'm I going to burn down my neighborhood with this or is it good?

jasonhc73

Cat herder, and dog toy tosser.
Joined
Oct 1, 2019
Messages
1,921
Location
Wichita, Kansas
2020-01-06.png



From the manual:
Solar Charging Mode(Per number of MPPT)
INVERTER MODEL 5KVA
Rated Power 4000 W x 2
Max. efficiency 96%
Max. PV Array Open Voltage 145Vdc
PV Array MPPT Voltage Range 60~115Vdc
Min. battery voltage for PV charge 34Vdc

I am assuming when hooking up PV to the PV input, Series sums the Voltage, and Parallel sums the Amperage.
I have two LV5048s (Left Picture). My plan is to do a 2S(maybe 3s) 4 times for each of the 4 PV inputs. I have 12 panels (right pic). I am planning to put at least 8 up this weekend, if the round2it's line up.

Can I do just one panel alone on each PV input? I see the 60~115VDC makes me think I have to have 2 or 3 in series of this panel.
 
You are right, you need between 60 and 115VDC for the MPPT charger to operate. If your array goes over 115V the charger will shut off. If you go over 145V you'll be in damage territory. You need to look at the Voc voltage for these. Under light loads the panels will float up towards Voc, under no load they'll be at Voc. Don't forget about temperature derating. As the cell temperature (note, this is not ambient temperature) drops from 25c (STC test point) their voltage goes up.
 
You are right, you need between 60 and 115VDC for the MPPT charger to operate. If your array goes over 115V the charger will shut off. If you go over 145V you'll be in damage territory. You need to look at the Voc voltage for these. Under light loads the panels will float up towards Voc, under no load they'll be at Voc. Don't forget about temperature derating. As the cell temperature (note, this is not ambient temperature) drops from 25c (STC test point) their voltage goes up.
Didnt realise the charger would shut off above the 115V. I had thought that the MPPT would simply not function as a tracking operation, but you would still charge at 115V and ignore the excess.....that's a lesson learnt for me. Thanks for that nugget. ;-)
 
From how I understand what has been said here by the MPP rep that is on the forum it will shut off. I might be wrong though :)
 
From how I understand what has been said here by the MPP rep that is on the forum it will shut off. I might be wrong though :)
Hmmm...i wonder how we can confirm that....i take it, it would be asking to much for a link to that conversation with the MPP rep?
 
Last edited:
This is the Info from the book:

PV Module Selection:
When selecting proper PV modules, please be sure to consider the parameters below:
1. Open circuit Voltage (Voc) of PV modules can’t exceed the maximum voltage of the PV array open circuit of
the inverter.
2. Open circuit Voltage (Voc) of PV modules should be higher than the minimum voltage of the battery.

The only other options the book mentions are charging source, solar/utility, one or the other or both.
Power balance when charging

If selected, solar input power will be
automatically adjusted according to
the following formula:
Max. input solar power = Max.
battery charging power +
Connected load power
Or

Max. solar power = Max. battery
charging power
 
Can't say for sure, but this may be an indicator of it. Probably worthwhile confirm it with MPP USA (or where ever). At worst they confirm it, at best they say the charger will run over 115V just not making use of all the power available from the panels.

1578360233277.png
 
Back
Top