Still chasing my tail when MPP 6048 shuts down?

[Jamasarah]

We have an MPP 6048 solar unit, 16, 250w used Santan solar panels, set in an array of 8 in series, and 8 in parallel, with 4-12v lead acid, deep cycle marine batteries.
We cannot figure out why the system keeps shutting down if we go over 289w, with the error code being 88 (parallel ID) in the manual ?‍
Also we have the low disconnect for the battery set at 44, ( is that correct)?

 

[Jamasarah]

We have an MPP 6048 solar unit, 16, 250w used Santan solar panels, set in an array of 8 in series, and 8 in parallel, with 4-12v lead acid, deep cycle marine batteries.
We cannot figure out why the system keeps shutting down if we go over 289w, with the error code being 88 (parallel ID) in the manual ?‍
Also we have the low disconnect for the battery set at 44, ( is that correct)?

Also I forgot to ask, why is my battery supply say too low when I’m barely using the batteries??‍?HELP it’s supposed to be 100° tomorrow

 

[mesquito_creek]

cold Start Voltage 46.0Vdc... Put your inverter into standby and get the battery bank fully charged at 53v+ before you turn your inverter and add load. Yes, in my opinion 44v is to low, especially with lead acid. I actually don't know much about Lead batteries, but if seem like you would not want any individual batter at less than 12.2 or something. I think there is a Lead acid default setting under #5 , put it on "FLd". But don't take it out of standby until you have a full charge.

I would set the low voltage cutoff at 48.8 or I would even go higher like 49.5. 12.2v X 4 batteries is 48.8, the absolute lowest I would go on lead. Hopefully a Lead acid person can help you out. Its not me...

This inverter needs the batteries to work right, you can't say in your head.. " I am producing 2000w on my array, why can't it run 1000w and charge my batteries off the floor at the same time". Once your battery bank is charged and can take a load without dropping the voltage below thresholds configured, then it will behave like its supposed to.

 

[Just John]

Also I forgot to ask, why is my battery supply say too low when I’m barely using the batteries??‍?HELP it’s supposed to be 100° tomorrow

I wish we had a cold front like that.

Anyway, you would be amazed at how many problems are mechanical connection problems. Try disconnecting everything, including busbars, clean, and put back together.

 

[mesquito_creek]

Since we are chasing you around on two different threads... Start by getting a volt meter out and telling us what the resting voltage of you battery bank is. Disconnect everything and let it set for an hour and report the voltage.

 

[John Frum]

We have an MPP 6048 solar unit, 16, 250w used Santan solar panels, set in an array of 8 in series, and 8 in parallel, with 4-12v lead acid, deep cycle marine batteries.
We cannot figure out why the system keeps shutting down if we go over 289w, with the error code being 88 (parallel ID) in the manual ?‍
Also we have the low disconnect for the battery set at 44, ( is that correct)?

A reasonable low voltage disconnect for lead acid is 48.24volts which roughly correlates to 50% depth of discharge.

 

[Zwy]

We have an MPP 6048 solar unit, 16, 250w used Santan solar panels, set in an array of 8 in series, and 8 in parallel, with 4-12v lead acid, deep cycle marine batteries.
We cannot figure out why the system keeps shutting down if we go over 289w, with the error code being 88 (parallel ID) in the manual ?‍
Also we have the low disconnect for the battery set at 44, ( is that correct)?

The 250w used panels on San Tan I see are 37.6 VOC. If you put 8 in series you are way over the input voltage of the MPP6048.

Now if you have 2 in series with 8 strings in parallel, then you would be fine at 37.6VOC per panel.

Next, you will need to list all your settings on the MPP in order.

 

[TomC4306]

16, 250w used Santan solar panels, set in an array of 8 in series, and 8 in parallel

Please clarify what this means. Probably overloading the input of the solar charge controller as previously stated by @Zwy

 

[Jamasarah]

Please clarify what this means. Probably overloading the input of the solar charge controller as previously stated by @Zwy

Our solar electrician said it up that way and figured out that everything would be OK ?‍And proceeded to hook it all up, BUT When we go over 300 W or so it shuts down, And this system is LV 6048! And should handle it what is wrong?

 

[TomC4306]

Maybe you should call your solar electrician

 

[Just John]

We have an MPP 6048 solar unit, 16, 250w used Santan solar panels, set in an array of 8 in series, and 8 in parallel, with 4-12v lead acid, deep cycle marine batteries.
We cannot figure out why the system keeps shutting down if we go over 289w, with the error code being 88 (parallel ID) in the manual ?‍
Also we have the low disconnect for the battery set at 44, ( is that correct)?

8 in series and 8 parallel means you have 64 panels.
How is it really connected?

I suspect you mean 8 parallel sets of 2 in series. But accuracy is important if you want help.

The used 250 watt panels at SanTan have the specs:

• Open circuit voltage (VOC): 37.6 V
• Max power voltage (VMP): 30.3 V
• Short circuit current (ISC): 8.85 A
• Max power current: 8.27 A

2 in series means
VOC = 75.2
VMP = 60.6

If you have a LV6048, it shows:
VOC max = 145v
MPPT range = 60-110v

It is very possible that voltage drop on the cables brings you below the required 60v VMP rating.

Edit to add, you may wish to get an additional 2 panels, and have 6 parallel strings of 3 panels in series.
Less voltage drop, and within the range you need for the SCC.

 

[Jamasarah]

8 in series and 8 parallel means you have 64 panels.
How is it really connected?

I suspect you mean 8 parallel sets of 2 in series. But accuracy is important if you want help.

The used 250 watt panels at SanTan have the specs:

• Open circuit voltage (VOC): 37.6 V
• Max power voltage (VMP): 30.3 V
• Short circuit current (ISC): 8.85 A
• Max power current: 8.27 A

2 in series means
VOC = 75.2
VMP = 60.6

If you have a LV6048, it shows:
VOC max = 145v
MPPT range = 60-110v

It is very possible that voltage drop on the cables brings you below the required 60v VMP rating.

Edit to add, you may wish to get an additional 2 panels, and have 6 parallel strings of 3 panels in series.
Less voltage drop, and within the range you need for the SCC.

Sent this to our solar Electriction ?He’s coming out when he can get free so we just shut it down

 

[Just John]

Sent this to our solar Electriction ?He’s coming out when he can get free so we just shut it down

Yes, basically it just means it will work better with 3 panels in series, and then parallel however many you can (with 16 panels, that would be 5 and leave you with an extra panel).

3 in series gives you 112.8 VOC (below the 145 limit, but cold temperatures can raise the actual VOC above that)
3 in series gives you 90.9 MPPT working voltage (within the 60-110v working voltage of the charge controller)

If it is set up with 2 in series, the 60.6v that gives might (after going through the cables) drop below the required 60v range of the charge controller.

The series strings should each give a maximum of 8.27 amps each to your charge controller (usually considerably less).
You can parallel 3 sets of these series onto a single 10 gauge wire to your charge controller, maybe 4, but the MC-4 connectors are not rated above 30 amps. In theory 3 parallel sets gives you over 24 amps, and 4 would give you over 32 amps.
Probably safest to do 3 series, and then parallel 3 of the series strings into a single 10 gauge run.

The panel spec sheet says max 15 amp fuse, so really you have to fuse each series connection separately. Then you can parallel them.

Anyway, 3 in series gives you less cable loss due to the higher voltage and is in the perfect range for the solar charge controller.
How many of the 3 series you parallel is up to you, personally I'd just run each series string on its own 10 gauge cable to the solar charge controller. Cable isn't that expensive. You do have enough panels that a fuse is required, and you can't fuse more than one series string. That would mean fuses on the roof of you run multiple series sets in parallel (to save cable), not an ideal location for fuses.

Sorry if I rambled and it isn't clear.

 

[Jamasarah]

Yes, basically it just means it will work better with 3 panels in series, and then parallel however many you can (with 16 panels, that would be 5 and leave you with an extra panel).

3 in series gives you 112.8 VOC (below the 145 limit, but cold temperatures can raise the actual VOC above that)
3 in series gives you 90.9 MPPT working voltage (within the 60-110v working voltage of the charge controller)

If it is set up with 2 in series, the 60.6v that gives might (after going through the cables) drop below the required 60v range of the charge controller.

The series strings should each give a maximum of 8.27 amps each to your charge controller (usually considerably less).
You can parallel 3 sets of these series onto a single 10 gauge wire to your charge controller, maybe 4, but the MC-4 connectors are not rated above 30 amps. In theory 3 parallel sets gives you over 24 amps, and 4 would give you over 32 amps.
Probably safest to do 3 series, and then parallel 3 of the series strings into a single 10 gauge run.

The panel spec sheet says max 15 amp fuse, so really you have to fuse each series connection separately. Then you can parallel them.

Anyway, 3 in series gives you less cable loss due to the higher voltage and is in the perfect range for the solar charge controller.
How many of the 3 series you parallel is up to you, personally I'd just run each series string on its own 10 gauge cable to the solar charge controller. Cable isn't that expensive. You do have enough panels that a fuse is required, and you can't fuse more than one series string. That would mean fuses on the roof of you run multiple series sets in parallel (to save cable), not an ideal location for fuses.

Sorry if I rambled and it isn't clear.

Yes, it’s ok, but I am totally brain dead now. I’ll just give this to the solar guy when he comes out.
My 16 panels are on cement blocks, close to the dirt, I’m in the high desert ?.
I have not a clue as to the specifics of our layout of series & parallel and how they they ended up?‍? because it’s so Greek to me

I am learning allot on this site though, in spite of my brain fighting me every inch of the way??‍?
Thank u so much?

 

[Jamasarah]

Maybe you should call your solar electrician

I have, he’s backed up for weeks

 

[Q-Dog]

Did you pay someone to set this up, and it isn't working? And now he can't come over to fix it?

 

[Jamasarah]

I have, he’s backed up for weeks

Did you pay someone to set this up, and it isn't working? And now he can't come over to fix it?

He’s a friend, and just helped us with questions, but we’re old & slow learners

 

[Jamasarah]

A reasonable low voltage disconnect for lead acid is 48.24volts which roughly correlates to 50% depth of discharge.

It will not go past the default, which is 42?‍?

 

[Jamasarah]

A reasonable low voltage disconnect for lead acid is 48.24volts which roughly correlates to 50% depth of discharge.

It will not let us change that setting (low DC cutoff voltage #29) which is 42.0 the default setting

 

[Jamasarah]

It will not let us change that setting (low DC cutoff voltage #29) which is 42.0 the default setting

In user defined selection, can low DC cut off voltage, and be set up to stay at that new setting, and not returning to default 42 volts?