vdc nearly same as vac

Topics: 1. General
Mar 23, 2015 at 11:44 AM
Firstly thanks for this software.

I have SB200HF inverter. I wish to have VDC uploaded to pvoutput. I have followed the tweaking instructions in the guide.
I have now discovered that the inverter is reporting vdc as nearly the same as vac
DC Spot Data:
    String 1 Pdc:   1.282kW - Udc: 284.79V - Idc:  4.621A
    String 2 Pdc:   0.000kW - Udc:   0.00V - Idc:  0.000A

AC Spot Data:

    Phase 1 Pac :   1.251kW - Uac: 251.27V - Iac:  4.980A
    Phase 2 Pac :   0.000kW - Uac:   0.00V - Iac:  0.000A
    Phase 3 Pac :   0.000kW - Uac:   0.00V - Iac:  0.000A
    Total Pac   :   1.251kW
Any ideas what is going on & how to get the actual vdc ??

Mar 23, 2015 at 12:06 PM
Edited Mar 23, 2015 at 12:06 PM
What makes you think these values are wrong? I don't see a problem here, but if you don't trust it, you can double check with Sunny Explorer
It will show the exact same values
Mar 23, 2015 at 12:23 PM
In my ignorance I thought the vdc would be considerably lower, ie 24 - 48 volts.

Can't use Sunny Explorer as I only run linux.

Thanks for your reply
Mar 23, 2015 at 12:42 PM
24-48V can be a valid value for 1 panel.
If you have a string of 10 panels, DC voltage will be 240-480V
This is an example, it all depends of the setup of your installation
Apr 12, 2015 at 10:27 AM
dear IcarusR,

-a- cfr comment by sbf the Udc depends on the nbr of panels in your installation,
-a.1- consult the datasheet for your panels, the datasheets indicate Umpp per panel
-a.2- Umpp = DC voltage at "Maximum Power Point Tracking" = best production
-a.3- then Udc by inverter = Umpp * nbr-panels (# in one string of serial connected PVpanels)

-b- you did not indicate your country/regio,
-b.1- I can't judge whether your Uac = 251,7 is abnormal

one can consult on wikipedia a worldmap with the overview of commonly applied Uac's
if you live in europe - Uac should at average be 230V - it should stay in the range 207<->244 Volt
so for Europe - your Uac is abnormal

-b.2- to validate Uac in your installation : you need to compare the Uac values at several moments
-b.2-a- in the morning (ater sunrise) and evening (before sunset)
with low power production by your PVplant AND low consumption
-b.2-b- value at noon (higher prower production)

-b.3- if these values are too different then please consult the SMA website
there are documents with guidelines for the dimensions of the mains connection

kr wim
Apr 12, 2015 at 5:03 PM
dear IcarusR, one point not mentioned

-c- Inverters are configured accoring the rules for a country/regio,
if Uac gets above a defined value, your inverter will reduce the energy injected in the mains
and might even reduce the production to "ZERO"

kr wim (note attached the worldmap)
Apr 12, 2015 at 5:28 PM
Thanks all for your answers. In my ignorance I made a schoolboy error.
I now realise that there is nothing wrong with my reported readings.

Please consider this thread resolved / closed.

Apr 14, 2015 at 11:51 AM
Edited Apr 14, 2015 at 6:49 PM
dear IcarusR, !! schoolboy error !!! no way

IF what you see is not what you expect - AND then - you dare not ask for info - that's "school boy error"

BY THE WAY (if that's english) -> the given answers might relate to the Udc question
BUT what is -> your ?the? explication about the - Uac ? i'm ancious to get info about this

kr wim