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New RV MPP LV2424 Questions

smoothJoey said:
What do you mean by parallel?
I don't see a problem with using 2 un-synchronised inverters each dedicated to its own leg.
I wonder if it was a misunderstanding.
You won't be able to get 240VAC but 120VAC should work fine.
Click to expand...

Thank you everyone for the input. Its very appreciated!

@smoothJoey

1593387313686.png

Each unit produces 20a max each. They are tied via communication cables and software to split the load. Thus combined in parallel make a max of 40a to the RV distro panel.

Both guys said this isn't possible nor recommended although its clearly designed for this. And that's why I bought these.

However, I think I found my solution though. Please let me know if anyone sees an issues with this.

Essentially I am dropping 1 leg like a 50a to 30a dog bone would do. This way my 40a will still power both sides of the Rv power panel. Still giving me the ability to turn off of an inverter if I want, or if one goes down. I've already ran the 8/3 wire to do this. Max output of the system is (2) 20a = 40a. I don't expect to ever run over 30ish amps. I think continuous we will see around 20a - 25a with air conditioning running.

1593393343717.png

This handles the ground when plugged into shore power.

Now I need to figure out where and how to add the switchable bonded ground when not on shore power. Does anyone know if the ATS inside these units does this automatically?
 

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Glad I asked.
I was under the mistaken impression that you had chosen option#1
I now understand that you have chosen option#3.
 
fr33fir3 said:
Thank you everyone for the input. Its very appreciated!

@smoothJoey

View attachment 16392

Each unit produces 20a max each. They are tied via communication cables and software to split the load. Thus combined in parallel make a max of 40a to the RV distro panel.

Both guys said this isn't possible nor recommended although its clearly designed for this. And that's why I bought these.

However, I think I found my solution though. Please let me know if anyone sees an issues with this.

Essentially I am dropping 1 leg like a 50a to 30a dog bone would do. This way my 40a will still power both sides of the Rv power panel. Still giving me the ability to turn off of an inverter if I want, or if one goes down. I've already ran the 8/3 wire to do this. Max output of the system is (2) 20a = 40a. I don't expect to ever run over 30ish amps. I think continuous we will see around 20a - 25a with air conditioning running.

View attachment 16402

This handles the ground when plugged into shore power.

Now I need to figure out where and how to add the switchable bonded ground when not on shore power. Does anyone know if the ATS inside these units does this automatically?
Click to expand...
Do *NOT* do this unless the manual says you can. The only way this can work is if the two inverters sync their sign waves. If the sign waves are not synced, you *will* blow up one or both of the inverters.

If you are on shore power, the inverters will follow the sign wave from shore and it may work fine. However, as soon as you are on battery, the sign waves will start to drift and all the magic smoke will come out of the inverters.
 
smoothJoey said:
lad I asked.
I was under the mistaken impression that you had chosen option#1
I now understand that you have chosen option#3.
Click to expand...

Thanks for bearing with me, I am sorry if I am not using the exact terminology. I am learning the lingo as I go.
 
FilterGuy said:
Do *NOT* do this unless the manual says you can. The only way this can work is if the two inverters sync their sign waves. If the sign waves are not synced, you *will* blow up one or both of the inverters.

If you are on shore power, the inverters will follow the sign wave from shore and it may work fine. However, as soon as you are on battery, the sign waves will start to drift and all the magic smoke will come out of the inverters.
Click to expand...

Well that's a bit scary.

I decided this route because of this:
www.mobile-solarpower.com

All-in-One Solar Power Packages

MPP and a few other manufacturers now sell a "complete off grid system in a box" that has: AC Inverter Solar Charge Controller AC Battery Charger Automatic Transfer Switch (if grid power is...
www.mobile-solarpower.com

I follow his youtube channel, he ran this for several weeks in his RV no problems while testing it.
 
fr33fir3 said:
Well that's a bit scary.

I decided this route because of this:
www.mobile-solarpower.com

All-in-One Solar Power Packages

MPP and a few other manufacturers now sell a "complete off grid system in a box" that has: AC Inverter Solar Charge Controller AC Battery Charger Automatic Transfer Switch (if grid power is...
www.mobile-solarpower.com

I follow his youtube channel, he ran this for several weeks in his RV no problems while testing it.
Click to expand...
I went out and found an MPPT manual...but I don't know for sure if it matches your model.
1593396392970.png
In it I found this

And this:
1593396225804.png

So, if your units have the parallel boards and are hooked up properly, it looks like your plan will work.
 
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fr33fir3 said:
Now that I understand the neutral ground bond this helps so much!
A relay would be super convent, however I think I would need a 50a relay right? The links are for 20a max.

Trying to find a TPDT switch that would work due to high amps. I'm ok with manual switch, because I intend to not be on shore power 99% of the time.
Click to expand...

I'm reallly lousy at reading esl manuals. The mpp may actually do what you want.
Its worth testing.
 
fr33fir3 said:
Does anyone know if the ATS inside these units does this automatically?
Click to expand...

I would think there are relays built in that do the switching. Why not contact MPP and ask them to be sure? I have been looking at Inverter/Chargers and they have built in relays that take care of the switching. I would be surprised if the MPP doesn't but you never know.
 
fr33fir3 said:
Trying to find a 3PDT switch that would work due to high amps.
Click to expand...
@smootheJoey
Have any suggestions on a 3PDT switch? Do I need a high amp switch?
This should work right? I know its overkill but its relatively cheap and solid.

Baomain Universal Rotary Changeover Switch SZW26-63 660V 63A 3 Position 3 Phase: Amazon.com: Industrial & Scientific

Baomain Universal Rotary Changeover Switch SZW26-63 660V 63A 3 Position 3 Phase: Amazon.com: Industrial & Scientific
www.amazon.com
 
Hey guys I got it all set up everything's running great on the DC side. However... when it's under load of anything more than a 400+ watts the MPP's go into fault mode and turn off. Even when I've got 1200 plus watts of solar coming in the AC side still trips. so I'm thinking it's maybe my wiring going back into the RV distro panel?

I'm not tripping any breakers or anything like that and the rest of the system it's only the MVP controllers that are doing this.

Anyone out there with LV 2424 experience run into this before?
 
fr33fir3 said:
Hey guys I got it all set up everything's running great on the DC side. However... when it's under load of anything more than a 400+ watts the MPP's go into fault mode and turn off. Even when I've got 1200 plus watts of solar coming in the AC side still trips. so I'm thinking it's maybe my wiring going back into the RV distro panel?

I'm not tripping any breakers or anything like that and the rest of the system it's only the MVP controllers that are doing this.

Anyone out there with LV 2424 experience run into this before?
Click to expand...
Please post an updated diagram.
I probably won't be able to see it but others will.
Probably not relevant but how did you end up dealing with the neutral ground bond switching issue?
Do you have a shunt?
 
The most likely cause is bad connection(s) on the DC. It will cause a voltage drop and the inverter will think the battery is low.

Ramp the AC. Load up as high as you can then look for warm connections. A cheap harbor freight thermal scanner is good for this.
 
smoothJoey said:
Please post an updated diagram.
I probably won't be able to see it but others will.
Probably not relevant but how did you end up dealing with the neutral ground bond switching issue?
Do you have a shunt?
Click to expand...
All diagrams are posted already. Post #39 on here shows the bonding I did.

Yes I have a shunt.
 
I might not have been as clear, that I'm reading my post again. DC side is running perfect!
It's the AC side when the inverters kick on. I can watch on the software when it gets a load it can hold it for a short period.

Example. I get about 5 seconds of microwave power.
Or I turned on the fan only for the AC and observed a 600watt load for about 30 seconds. Then it faults. So I think it's an issue with the LV 2424. Maybe a setting I don't have right..
 
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