Enecsys Micro Inverters

[Ramjam]

I did the Enecsys micro inverter training but they've got a technical hole in what they're offering???

They state that you can only connect a maximum of 16 micro inverters to one 30mA RCD so at 190w 16 panels is 3kWp so if we want 4kWp then we need 2 AC buses and 2 RCDs and unless we're doing some RCD schenanegans on the inverter side of generation meter then it won't work. Either way the pictures in the training materials don't look right.

They also show the lockable AC isolator at the wrong point in the circuit, the lockable AC isolator has to isolate the entire AC circuit including the generation meter.

Does anyone out there use these inverters if so how do you wire them up?

 

[SolarCity]

Where did you do your training, Ramjam, and how much did it cost?

 

[Energetic]

We wanted to use them on a job but couldn't find a panel that was compatible that would fit on the roof. Great idea but too limited at present.

 

[Ramjam]

BiggsSolar: You call enecsys and it's a half hour telephone training session and an exam to complete at home and email back.

Energetic: I've been considering it with a sharp poly panel as I use sharp monos normally but they're not on the compatibility list.

 

[edexlab]

I did the Enecsys micro inverter training but they've got a technical hole in what they're offering???

They state that you can only connect a maximum of 16 micro inverters to one 30mA RCD so at 190w 16 panels is 3kWp so if we want 4kWp then we need 2 AC buses and 2 RCDs and unless we're doing some RCD schenanegans on the inverter side of generation meter then it won't work. Either way the pictures in the training materials don't look right.

They also show the lockable AC isolator at the wrong point in the circuit, the lockable AC isolator has to isolate the entire AC circuit including the generation meter.

Does anyone out there use these inverters if so how do you wire them up?

Had a look at ecobuild and they use a plug similar to the ones used on Sma inverters and their own junction boxes I'm planning on taking cable surface/swa or contained upto the roof which obviates the need for an RCD unless;
they are transformerless ,nothing definite about the topology on enecsys site so I assume that because of the low weight that they are , then with this set up does it specify 30mA rcd in the training guide ?

 

[Ramjam]

The micro inverters do have transformers. According to the instructions they do need RCD protection but they each have a small amount of earth leakage hence the limit of 16 of the smaller or 13 of the big ones per AC branch. Each branch then needs it's own RCD so it requires a different setup on the AC side back down in the garage or wherever you house the AC switches and generation meter. I'm still waiting for a call back (over 2 weeks now) to discuss the AC side because their training material contradicts itself. I get the impression that there are not many installations and what there are may well be experimental.

You need to buy every little component of the system separately which is a drag, there are no kits. I think it's all a bit too new yet but it will open the door for those awkward multifaceted roofs that at the moment we advise against.

I hope enecsys can learn as they go but unless they smarten up then someone else will learn their lessons and take their place in the market.

 

[Jie]

I've got the 30 minute induction in 2 days time. We use Sharp Poly 235s and they arent on the list but the guy who runs Enecsys said he would add them to the list, although it would take up to 2/3 weeks for testing. So say the system we are to install is 3.6kW..... Am I correct in reading that I would need to split them into 2 strings of MI's with 2 seperate RCD'S?

 

[Ramjam]

I'm very interested as to what they give you as an answer to that question, if you look at the photo in the training material then they bring both AC branches into one AC isolator and then through a meter to the RCD. This is inconsistent with their own training. From what I can gather you'd need to bring those two AC branches downstairs separately (2 AC isolators in the loft) then into a box housing 2 RCBOs then through a generation meter into another AC isolator (lockable only in the off position) before connecting to the supply through a breaker in a distribution board either your own or an existing.

Please post the answer when you get it becuase they've never answered that question for me hence me producing no quotes for micro inverters.

 

[Noddy67]

interesting. I did the induction and spoke to a technical bod. My understanding was that their cabling wasn't up to the full 16 amps but if you split them with two seperate 'strings' it wouldn't exceed the 16amps after the AC isolator.

I hope so as I'm fitting on this basis tomorrow.

I agree that Enecsys seem a little 'young' but held the inverter and cabling for the first time today. very solild looking (I was fearing someting a little flimsy but it looks the biz). I'll let you know how the fitting goes.

 

[poheZ]

Just a few questions!:

How do they attach to the module?
Have these micro inverters been road tested over a prolonged period of time in another country?
Is there an equivalent from another manufacturer?
where is the link to the telephone training/info?

 

[Noddy67]

Hi,

1. They attach to the rail not the module.
2. Don't know - think they're too new
3. Don't know
4. I contacted Enecsys via the wholesaler - I suppose that's their way of controlling access to just installers who can answer most of your questions.

I did the job on Wednesday with 15 micro inverters. The set up of the monitoring took a little more time than it shoudl but it was the first time. Next time it would be quicker and less frustrating.

The connections were push-click and again solid. Oddly, it was much more difficult to explain the connection from each pair to the next but when you were up there with male/female connections it was very straightforward.

One thing that did hack me off was - when on the way to the job for this first job - I realised there weren't any bolts to connect them to the rail. Called up Enecysys and asked about this of their technical department, what to do/use. His first words were a pretty dismissive "This was covered in the induction." ie your problem. A quick sharp verbal punch back at him and he told me they were 8mm bolts that "most installers had with them" but he couldn't be much more specific than that.

I don't think they'd got the hang of this client-service business, but the gear looks OK.

 

[poheZ]

what was the cost for the micro inverters?

 

[Noddy67]

I don't want to put trade prices on this open forum but feel free to PM me and I'll certainly let you know.

 

[Von Vardo]

Does anyone have any further info on this? I'm due to install 14 of the SMI-240 micro inverters and 14 Sanyo 250W panels next week so need some clarity!

I asked Enecsys about the 13 inverter per AC branch limit and received the following reply:

The number of SMI units is based on the 3.8 kw=your allowed to go up to per branch based on our G83 Certification . i.e 16amps
The practical way is to have separate branches and each branch requires it own Isolator and this would then be required to feed into the consumer unit, with ideally a 30milli amp RCD fitted.

The RCD obviously provides extra protection and in case some time in the future someone adds a socket or something to the circuit.
The best practice would be to have RCD for each branch, I’m aware that people don’t always carry out this practice.

Based on this reply I believe that my install of 3.5kWp should be fine on 1 AC branch.

 

[edexlab]

Just finished our 2nd enecsys job and some aspects of the system are good, some bad although it is a straightforward install

but there is one issue I'm not too happy about, if you should be working on these systems you need to be aware that even with the AC isolators turned off but with the dc connectors still attached to the invertors there is an AC voltage present between the line and earth on the cabling
ie you can touch any wire individually or even L to N no voltage but L to Cpc there will be a voltage when tested it was ranging between 2v and upto 120v this was discovered while connecting the enecsys cable to our cable back to the isolators ,this ocurred because the roofing team had fitted the inverters / modules before we had arrived on site with us having been delayed on a previous job obviously this will not be allowed to happen again, and the installation method does need to be followed ,
ie rail and ac cable installed and tested first, panels connected only when the Ac cable is into the isolator
but it has got me thinking about real life scenarios eg having to change an inverter or cabling due to damage ,to do it safely you'll need to disconnect the Dc on the roof which is not very practical
I've reread the enecsys installation guides to see if there is any warning and there isn't anything specific to this ,I've also emailed them and await an answer.

Setting up the monitoring is time consuming although the monitoring is pretty good but raises some questions when you are looking at several modules and there's one which is doing a lot less than the others on an identical aspect, then you might see another module doing the same and the original improving ,I think this could be something to do with the temp coeff as it was on one of the hotter days we've had lately. I can see customers ringing up everytime they see a panel doing this and the installer not having a logical explanation, another question raised with enecsys

 

[SRE]

My Recent PV Install. - MoneySavingExpert.com Forums Thought this was interesting - looks like a lot of shading to me, not a job I'd have looked at but happy to stand corrected if microinverters can get round this. Great pictures of the monitoring equipment, but as Edexlab says potential for loads of unanswerable questions. We already have problems with utilities not getting the FiT confirmation through quickly enough (or not at all in one case since feb) and although it's not our fault we feel obliged to help out. The micro inverters could potentially cause even more problems.

I'm tempted regularly, but the feedback coming through suggests it's a bit too soon for us yet.

 

[Surboy]

Personally I am not 100% convinced about microinverters as there are too many parts that could go wrong and according to some PV websites they can create hotspots in the panels. My supplier recommended Tigo Energy optimisers, planning to use them in my next install where shading is an issue. Will report my experience once I try them.

 

[jetski]

My Recent PV Install. - MoneySavingExpert.com Forums Thought this was interesting - looks like a lot of shading to me, not a job I'd have looked at but happy to stand corrected if microinverters can get round this. Great pictures of the monitoring equipment, but as Edexlab says potential for loads of unanswerable questions. We already have problems with utilities not getting the FiT confirmation through quickly enough (or not at all in one case since feb) and although it's not our fault we feel obliged to help out. The micro inverters could potentially cause even more problems.

I'm tempted regularly, but the feedback coming through suggests it's a bit too soon for us yet.

Hi there, that is my system in the link, the shading is not as bad as it may appear it look's worse as it's showing the clouds at the time the picture was taken the tree only causes the shading more or less on the three south left panels late afternoon when the sun comes round. I must admit I've gained quite a lot of information from here and the MSE forum and realise that micro inverters are not everyone's cup of tea so I suppose only time will tell.

 

[Von Vardo]

Has anyone else heard of a problem with a recent batch of micro inverters? I have some on order but the wholesaler has been "advised of a potential issue with the recent production batch."

 

[Noddy67]

Back in early june I had a batch that included some with out with incomplet software; they swapped them all out so i'd guess that's that, but what have you heard? Which wholesaler?