Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Help connecting MPP LV 5048 split phase
#1
I recently bought an MPP Solar LV 5048. It's hanging in the barn waiting for me to build my battery and hook up wires. Unfortunately, the manual is completely useless as far as explaining how the unit should be connected with the existing AC.

I live in "Hurricane Alley" and also "Lightning Alley" so goal #1 is to have capable backup power when grid power goes down which it does frequently. We were out for 2 weeks after Irma. Secondary goal is to run as many base loads as possible while the grid is up.

I have a 200A main service panel at the house which feeds a 100A sub-panel in the barn. Solar, battery and inverter will be at the barn.

This unit supposedly has an "internal automatic transfer switch". I'm not sure if that's true, but it does have AC input and output and can be configured for battery priority or line priority. I just can't wrap my head around how to connect the AC inputs and the AC outputs to my sub-panel in the barn. I'd like to do this hard wired and also prevent any chance of feeding back to the grid. What will I need in order to do this safely and effectively? And would I still be able to power some circuits in the house or would I be stuck only powering barn circuits?
Reply
#2
This is an off grid unit. You connect AC input from your panel to the inverter and then the loads on the Inverter output.

This unit cannot power the grid and no you cannot back feed to your house. You need to pull separate wires to the house from the inverter if thats your main goal.

Highly recommend to bring in an electrician to help you out. The manual it self rather clearly explains how it works even though its not the most comprehensive manual.
The Ultimate DIY Solar and build place
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 83kWh LiFePo4 | 10kWh 14s 18650 |  66*260W Poly
Upcoming: 14S 18650~30kWh | Automatic trip breakers, and alot more
Reply
#3
(10-17-2019, 10:47 PM)daromer Wrote: This is an off grid unit. You connect AC input from your panel to the inverter and then the loads on the Inverter output.
Thanks for your response daromer! I respect your knowledge and have learned a great deal from your posts and videos.



The manual calls it a "Hybrid Unit". I have to ask how is this considered an "off grid" unit when the default output source priority is "Utility First"? From the manual, pg. 14: "Utility will provide power to the loads as first priority. Solar and battery energy will provide power to the loads only when utility power is not available." This is behaving like a UPS, no?



Since all of my loads are already on the panel, are you saying I would need to add an additional sub-panel and move all my load circuits to that new subpanel?



(10-17-2019, 10:47 PM)daromer Wrote: This unit cannot power the grid and no you cannot back feed to your house. You need to pull separate wires to the house from the inverter if thats your main goal.

So during the last prolonged hurricane grid outage, I ran a noisy, gas hungry, 8kW gas generator outside the barn. I plugged it into my welder outlet in the barn and back fed it into the house. But only after turning off the main service panel breaker so power didn't feed back into the grid. This worked fine aside from the gas and noise. While I was hoping for a more elegant solution, why couldn't this inverter couldn't do the same thing?




(10-17-2019, 10:47 PM)daromer Wrote: Highly recommend to bring in an electrician to help you out. The manual it self rather clearly explains how it works even though its not the most comprehensive manual.



The manual is fairly clear on most items except the section on AC input / output connections. From page 8:







"Short-circuit phase L and neutral conductor N 3 mm?" What does that even mean? I discounted the entire manual after reading that line!



I'm a DIY'er... I built the barn and wired the service to it myself. That was simple, but this is definitely more complicated. Even if I hire a licensed tradesman, I really need to understand how the system is designed. I suspect my solution will require transfer & bypass switches. I'll do some more reading.
Reply
#4
You can of course disconnect the mains and backfeed but that is a worksround and not very ellegant. The best is to Power all or part of the equipment from the inverter all the time.

You cna change priority order. And they call it hybrid There because you can either Power ur load via grid or battery. Its not hybrid because it cannot sell back

They state you should Short those to on incomming. The reason is that they Bring in 230vac and not splitphase. Once again its most likely wise not to install it ur self. DIY or not but its lethal levels of current Smile with that i cannot hinder you.
The Ultimate DIY Solar and build place
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 83kWh LiFePo4 | 10kWh 14s 18650 |  66*260W Poly
Upcoming: 14S 18650~30kWh | Automatic trip breakers, and alot more
Reply
#5
Short-Circuit means to take a wire and connect those two terminals together directly. Not sure what the 3mm would be, the wire size maybe?
Proceed with caution. Knowledge is Power! Literally! Cool 
Knowledge is Power; Absolute Knowledge is Absolutely Shocking!
Certified 18650 Cell Reclamation Technician

Please come join in general chit-chat and randomness at Discord Chat (channels: general, 3d-printing, linux&coding, 18650, humor, ...)
(this chat is not directly affiliated with SecondLifeStorage; VALID email req'd)
Reply
#6
(10-18-2019, 11:34 AM)Korishan Wrote: Short-Circuit means to take a wire and connect those two terminals together directly. Not sure what the 3mm would be, the wire size maybe?

Thanks Korishan... I'm aware of what a short circuit is. But where I come from, short circuiting a hot leg (L) with the neutral (N) equals a dead short! ?



This has to be a Chinglish typo. I'll bet they're referring to the neutral and ground being already bonded in the inverter. I'll contact the manufacturer support to see what they say.
Reply
#7
Perhaps it means short the wires together before connecting anything to make sure there is no stored charge on the terminals? I'm surprised it even takes a neutral input. My AIMS split phase does not take N input, just L1+L2 240V. It makes the neutral itself with the internal transformer.

As others have said, please have an electrician install it...
Korishan likes this post
Reply
#8
(10-18-2019, 02:16 AM)cowpen Wrote: The manual is fairly clear on most items except the section on AC input / output connections. From page 8:



"Short-circuit phase L and neutral conductor N 3 mm?" What does that even mean? I discounted the entire manual after reading that line!

Ok, now I understand what this means.

Quote:3) Insert AC input wires according to polarities indicated on terminal block and tighten the terminal screws. Be sure to connect PE protective conductor first.

That's the key instruction right there. So on the input before connecting anything else, it looks like they want you to short L and N to make sure everything is discharged before connecting anything else.

This is my best guess, anyways.
I would agree with mike and get an electrician to do that part, especially if you can't get a clear description as to what this is for and why. That way, if something goes wrong, it's the electricians fault and you're covered under their insurance (i would hope) or at least you can state that you had a certified electrician do the hook up and get a refund/return/etc from where you go the inverter.
Proceed with caution. Knowledge is Power! Literally! Cool 
Knowledge is Power; Absolute Knowledge is Absolutely Shocking!
Certified 18650 Cell Reclamation Technician

Please come join in general chit-chat and randomness at Discord Chat (channels: general, 3d-printing, linux&coding, 18650, humor, ...)
(this chat is not directly affiliated with SecondLifeStorage; VALID email req'd)
Reply
#9
Also note that most of us Arent electrician and advices from us may not be the best. Most of us have built installs and for instance k have done electric work for many years but Still have had an electrician to inspect My install so its Up to code Smile
The Ultimate DIY Solar and build place
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 83kWh LiFePo4 | 10kWh 14s 18650 |  66*260W Poly
Upcoming: 14S 18650~30kWh | Automatic trip breakers, and alot more
Reply
#10
Just to follow up on this, I heard back from MPP Solar support. They basically said it's a translation typo. L and N shouldn't be shorted.

They did add that if the AC output mode is set to " 2A0 - Parallel output in single phase" then L1 and L2 output should be shorted together to use both phases combined at 120V. I'll be using 2A2 in my application.

Korishan likes this post
Reply


Who read this thread?
35 User(s) read this thread:
AZ_Tekkie (Yesterday, 02:52 AM), mart1nn (10-21-2019, 05:56 AM), OffGridInTheCity (10-17-2019, 11:04 PM), MNRosado (11-16-2019, 01:28 PM), 100kwh-hunter (10-27-2019, 07:13 PM), Doin it (10-19-2019, 06:46 AM), juanjo57 (11-17-2019, 06:43 AM), gpearce52 (10-29-2019, 07:10 AM), 7h0r (10-22-2019, 12:54 PM), LPG (10-25-2019, 04:51 PM), poolizei (10-26-2019, 06:42 PM), papanyan (11-06-2019, 08:14 AM), xyoung347x (10-29-2019, 02:46 PM), w0ss (10-28-2019, 02:00 AM), barry (10-29-2019, 09:04 AM), ptchernegovski (11-15-2019, 03:30 AM), RikH (11-04-2019, 10:14 PM), ajw22 (10-19-2019, 01:50 PM), Solardad (11-14-2019, 02:37 AM), daromer (11-16-2019, 02:53 PM), mike (10-25-2019, 07:22 PM), Korishan (11-16-2019, 02:39 PM), PAF (10-19-2019, 03:29 PM), jdeadman (10-25-2019, 07:26 PM), Geek (10-24-2019, 02:55 AM), Ivo Staelens (10-31-2019, 10:57 AM), mr_hypno (Today, 04:49 PM), Tentious (10-25-2019, 08:28 PM), Oz18650 (11-02-2019, 11:29 AM), not2bme (11-13-2019, 05:45 PM), HughF (10-18-2019, 02:58 PM), gpn (10-18-2019, 05:37 AM), hermitdave (10-18-2019, 08:02 PM), cowpen (11-16-2019, 02:26 PM), manuelflorencio (Yesterday, 12:01 AM)

Forum Jump:


Users browsing this thread: 1 Guest(s)