AP Systems DS3 Microinverters

[Riderice]

I just ordered six DS3 units, the 750w version, for an add-on array I'm building (tying into the GEN input to my Sol-Ark 15k). I purposely didn't get an ECU with them though, because 1) I don't really care that much about monitoring individual performance and 2) more importantly, it doesn't seem *necessary*, based on the installation manual.

So my question is, for anyone with experience using these, or specific knowledge: will they work without the ECU, basically just plug-and-play on the microinverters?

The manual says basically "hook everything up, apply AC power, units will begin operating after a few seconds/minutes whatever". But there's a big discussion over at solarpaneltalk.com about all sorts of problems people have had with these, and AP requiring installers (AP famously "doesn't support DIYers", wtf) to do firmware updates before installing, which of course requires the ECU...

 

[ncsolarelectric]

I know it would work fine with Hoymiles microinverters. AP Systems are a mystery to me.

 

[Riderice]

AP Systems are a mystery to me.

Yes I'm starting to feel that way. There are 2 different installation guides - one says the trunk cable has "brown, blue, and yellow/green", the other guide says "black, red, and green". None of those descriptions match my cable, which has black, red, and blue...?‍ I'm assuming black and red are hot, blue is ground...but why blue and not green...?

 

[ncsolarelectric]

Yes I'm starting to feel that way. There are 2 different installation guides - one says the trunk cable has "brown, blue, and yellow/green", the other guide says "black, red, and green". None of those descriptions match my cable, which has black, red, and blue...?‍ I'm assuming black and red are hot, blue is ground...but why blue and not green...?

View attachment 168909

208V 3Phase is code Black, Red, Blue. There is no ground wire here.

 

[Riderice]

208V 3Phase is code Black, Red, Blue. There is no ground wire here.

Yep, this cable is labeled "3 phase" upon closer inspection, which means Renvu sent me something different than what I ordered... But on the other hand, 3 wires is still 3 wires, right? I wired it up using the blue for ground, and everything seems okay?‍ (1 panel plugged into 1 DS3, got the slow green blink and after a few minutes it was delivering power to my Sol-ark GEN input). Gives me confidence to go ahead and hook up the other 11 panels and 5 DS3s...

 

[Riderice]

Last update (hopefully): to answer my own question, "yes", they appear to be plug-and-play. Don't *need* the ECU...unless you need to update their firmware or settings or anything I guess...

After a nail-biting 5 minutes or so, when I threw the switch connecting the string to my Sol-ark, they started producing energy?

 

[zanydroid]

Did the trunk cable get “fulfilled” separately by Renvu or was it part of something factory assembled by AP systems?

How did you mount that bell box to the rail?

You don’t want an inspector seeing any junction box that has the blue wire used as ground (code violation). My local inspectors don’t go on the roof and look. I don’t think it makes a meaningful safety difference in residential though.

 

[fafrd]

Did the trunk cable get “fulfilled” separately by Renvu or was it part of something factory assembled by AP systems?

How did you mount that bell box to the rail?

You don’t want an inspector seeing any junction box that has the blue wire used as ground (code violation). My local inspectors don’t go on the roof and look. I don’t think it makes a meaningful safety difference in residential though.

Good idea to purchase some green electrical tape and wrap a piece around every end of that blue wire… (probably good enough to meet code if anyone notices the color and asks what that conductor is carrying…).

 

[pvgirl]

FYI:

NEC 2023 250.119 (C) Multiconductor Cable​

One or more insulated conductors in a multiconductor cable, at the time of installation, shall be permitted to be permanently identified as equipment groundingconductors at each end and at every point where the conductors are accessible by one of the following means:

1. Stripping the insulation from the entire exposed length.
2. Coloring the exposed insulation green.
3. Marking the exposed insulation with green tape or green adhesive labels. Identification shall encircle the conductor.

 

[zanydroid]

Good idea to purchase some green electrical tape and wrap a piece around every end of that blue wire… (probably good enough to meet code if anyone notices the color and asks what that conductor is carrying…).

It is a little hard to parse the code on this but I believe EGC remarking in a cable is disallowed.

You can do grounded conductor remarking though

 

[zanydroid]

FYI:

Is this new? I was pretty sure it was ambiguous/confusingly worded (and leaning towards disallowed) to remark EGC in a cable.

Didn’t think the rule was that important anyway ?‍

 

[fafrd]

It is a little hard to parse the code on this but I believe EGC remarking in a cable is disallowed.

You can do grounded conductor remarking though

I thought any insulated conductor could be remarked / recolored with tape…

 

[zanydroid]

Looks like that 250.119 long ago only allowed it when “where the conditions of maintenance and supervision ensure that only qualified persons service the installation“, and last time I looked at this I only looked at the relabeling section for current carrying conductors

 

[Riderice]

Did the trunk cable get “fulfilled” separately by Renvu or was it part of something factory assembled by AP systems?

How did you mount that bell box to the rail?

You don’t want an inspector seeing any junction box that has the blue wire used as ground (code violation). My local inspectors don’t go on the roof and look. I don’t think it makes a meaningful safety difference in residential though.

I ordered from Renvu and I assume they just cut me a section with 6 connectors. What they had listed was the split phase 10awg (B/R/G), I didn't even know a 3-phase version (with blue) existed until I got it?‍

Pretty proud of myself on the box mounted to the rail!? Drilled 2 holes in the box, and used some leftover footpad/rack t-bolts to secure it. Keeps the box off the roof surface, and saved me from drilling a rooftop mount point for the conduit.

My system was already inspected, and they didn't even get on the roof for that. So, pretty much a non-issue.

 

[zanydroid]

Yeah TC comes in a bajillion colors for the individual conductors ?‍

Ok, makes sense how you fit it… Is that unirac? They actually have a conduit-to-rail fitting that attaches the conduit parallel to the rail. I have a few of those that I did not end up using. I think they use the footpad bolts.

 

[Riderice]

Yes Unirack (with IronRidge flashfeet). The conduit goes straight down the roof from there, just a short section, then over the gutter to wall. So no parallel conduit-to-rail connections needed.