Iskra ME168 meter with PV panels

Volthar

Hi All,
I have a problem understanding what the Iskra ME168 meter shows me in regards to energy import, export and consumption. I have a set of PV panels on the roof of my new home and I took a look at the meter this evening to see what is going on with my energy consumption. Unfortunately manual for this model is not available but it is similar to ME162. My problem is that the display constantly shows the right pointing arrow (->) which according to ME162 manual means I am exporting electricity. The problem I have is that the direction of the arrow does not change whatever I do. All lights on, dishwasher on, washing machine on, and it was already dusk. On top of it my overall consumption seems to be constantly increasing. And now the cherry on the top... I looked in my hot press and the PV panel's AC isolator was in OFF position. I cannot test anymore as it is already night.

Can anyone help me understand what is going on?

Thanks in advance.

quentingargan

You'd need to check what the wires going in and out of the meter are doing. But if the isolator from your panels was OFF, then you won't be producing any electricity, so the meter would only be showing imports. It would seem either way that your meter is wired back to front - the grid is going onto the wrong side, so what should be showing as imports is actually showing as exports.

Your inverter will have some way of telling you something about electricity being produced by your panels.

Might I ask why your AC isolator for the inverter is in the hotpress? Any chance you have a diversion device there heating your hot water with surplus electricity from the panels? The AC isolator for the panels should be beside your inverter and accessible. It shouldn't be in a hotpress.

Volthar

Thanks for your reply. I have no idea why it is done this way. It is upstairs above the fuse box. I could not find the inverter. Might be in the attic? Sorry I am quite new to all this and just got the keys to this one a week ago.

I took a look at neighbouring house meter and it shows an opposite direction (showing import). The other house is empty so conditions were same as in mine with lights and appliances off . It was at dawn so turning the isolator ON did not make any difference.

Does it sound like someone messed up?

quentingargan

Chances are the inverter is in the loft. I would pop up there during daylight and make sure it is working. Usually there is a user interface there that allows you to read power production. Make sure all isolators are on.

Your AC isolator for the inverter should really be beside the fuse board or somewhere accessible. How many panels to you have? Generally on new installations, there is no need to have a meter because the inverter records production and you aren't getting paid for exports at present, unless the house was connected before January this year (when there was an export tariff available).

Is this ISKRA meter your main house meter as used for bills, or one that is supposed to monitor the solar only?

Volthar

I looked at the schematics provided by the builder. There are 3 panels and the system uses M215 microinverters. I suppose this is why I could not locate them as these seem to be installed under PV panels. The AC isolator is above the fuse box and both are in the hot press upstairs. It may be idiotic question but is it normal that there are no visible cables sticking from the AC isolator? It just sits on the wall above the fuse box.

Another thing is that when I have gone up to the attic in search for the microinverter I found a thick black cable sticking from the roof where the panels are but it is not connected to anything. I guess I need to wait until tomorrow and talk to site's electrician.

The Iskra meter is my main house meter used for bills. I do not have any device that would show me that the panels do their job, this is why I investigated what the direction of the arrow means. I am at work at the moment but will pop in there during lunch time to check what the meter shows when the sun shines at the panels.

quentingargan

Personally I don't like micro-inverters. The inverter is the one part of a PV system with power electronics, IGBTs, Mosfets and other components that are very likely to fail during the systems 25 year lifespan. It is ridiculous that power electronics, which can fail, are put on a roof under a panel where getting at them is going to cost about €500. Micro inverters should really only be used if you have partial shading on an apartment block where you can get at the panels to replace faulty inverters. And usually micro inverters are more expensive - it wasn't scrimping. Seems daft to me.

You also should have stickers. If you PM me your address, I can stick a sheet of these labels in the post. If there was a fire, you would want to have access to that isolator, so it should be clearly labelled, and located beside the fuse board. There should also be a warning label at the meter box and "dual supply" labels on the fuse board.

I should imagine that now you have the AC isolator on, that meter should occasionally work in the other direction if all household loads are switched off. So all that said, the system will probably work fine as long as the MCB and isolator are both on. (the isolator will get its power from an MCB in the fuseboard).

Volthar

quentingargan wrote: »

I should imagine that now you have the AC isolator on, that meter should occasionally work in the other direction if all household loads are switched off. So all that said, the system will probably work fine as long as the MCB and isolator are both on. (the isolator will get its power from an MCB in the fuseboard).

I will check if the meter changes direction when I am there during lunch time. hope that the sun will still be out. All household loads are switched off as I haven't moved in yet. If it does change the direction to import this would mean that the meter is connected other way around. I hope this won't affect my bills but nevertheless would need to be rectified by the builders. I will also tell them about the missing warning stickers.

Thanks for your help. I will update this once I know more about what is going on.

freddyuk

Quote:Another thing is that when I have gone up to the attic in search for the microinverter I found a thick black cable sticking from the roof where the panels are but it is not connected to anything. I guess I need to wait until tomorrow and talk to site's electrician....unquote..

I would be careful of going near any cables from the roof until you know what is going on. They may be live.

Volthar

Surprise surprise... they forgot to connect the PV panels to the junction box up in the attic. Wonder how "everything was tested" prior to completion. Now everything seems to be working as per manual. Thanks.