Inverter help ?

[ecogeorge]

Morning folks -just purchased a new small grid tie inverter to run 3 x 250w panels on the garage wall.
Inverter is DORFMULLER SOLARANLAGEN GMBH DM1 700/70.
It has no display just a green power led that illuminates immediately ac power is applied.
I have 100 volts dc at the input but the inverter just does not appear to export any power. I would have expected dc volts to drop once power was being harvested.
Looking at a smart meter i actually think it may consume some power as i plug it in and out !
Having previously connected a single panel inverter i know my smart meter is correct -could see power going to grid....
Anyone any experience of these inverters ??
rgds George

[Tinbum]

Seems to be very little online about that inverter and the company.

[Moxi]

I could be wrong George but the Dorfmueller has more than a passing resemblance to Sunnyboy inverters so I wonder if they share much of the internal infrastructure? You can download sunny boy manuals online and they may give you some insight into the led flashing sequences and any problems ?

Moxi

[ecogeorge]

Seems to be very little online about that inverter and the company.

Yes -I can see that now . Its just sat there with solid green led.
George

[ecogeorge]

May need to open the box !
George

[nowty]

Morning folks -just purchased a new small grid tie inverter to run 3 x 250w panels on the garage wall.
I have 100 volts dc at the input but the inverter just does not appear to export any power. I would have expected dc volts to drop once power was being harvested.

100V open circuit is a bit low for 3 standard 250W panels, I would have expected around 110V, are you sure its bright enough ?

Whats the panel spec ?

Are you 100% sure the polarity of the DC side into the inverter is correct ?

Can you hear any relays clunking away from the unit ?

[nowty]

Another thought, is it wet ?, I sometimes get a problem with my original system starting up in wet weather due to insulation failure errors, resistance to earth of the DC side. Happens more with older panels and especially if your testing them sat on the ground.

[ecogeorge]

Panel voltage is currently 101v dc
Polarity is correct.
Panels are total theoretical oc voltage of about 110v BUT a very grey day here today. Would have thought with a starting voltage of 70v it would connect and produce a few watts.............
There are 2 inputs which appear to be connected as i get panel voltage with test leads on unused pair.
Panels at 101v -plug in connectors and voltage appears on meter of 101v. No relays click (if any) -only a tiny transformer hum which is present all the time.
FWIW -i did connect a Soladin windmaster (not programed) and its relays clicked in and out continuously so i disconnected it thinking paramiters not set ?? is this relevant ???
George

[nowty]

Its a pity the inverter does not seem to give you any diagnostic info, not even a blinking led light like a Soladin.

I would hold on for a brighter day in the first instance, just because the OC voltage is above 70V, does not necessarily mean it will actually start. It should attempt to, but if there is not enough power available it won't complete its pre grid connect checks.

If it wont start in brighter conditions, then you definitely know there is something else wrong.

[ecogeorge]

Brighter day today -dc volts up to 105v dc but not a peep from inverter.
Frustrated so i installed 3 x enphase inverters (which i had) and these all exported power until nearly 6pm when it really was dark..........
Will tinker again with inverter at a later date........
Thanks for your inputs..........
George