Oversizing KID and Limit with AmpLmt?

Started by pmaril, April 21, 2017, 12:16:58 PM

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pmaril

My name is Pablo Maril, I am the installer and system designer for Efergía, in Argentina, and have a question regarding the Kid, and oversizing it.

I have a 24V nominal system, working with 2 series of 2 Canadian CS6K-265P modules. A total of 4 modules hook up to the Kid. The system was originally designed for 3 Canadians, but our client is rising up the number of modules to 4.

The question is, since the String calculator is in 1.3 inverters, and the recomendation is that over 1.2 go to another inverter (Classic, for example), we NEED to keep costs at the lowest possible number.

It is possible to limit the current on software via the AmpLmt menu? So I could avoid adding a second inverter or going to one more expensive one.

I have 265Wp x 4 modules = 1060Wp (@STC) => 1060Wp / 24V (nominal) = 44.16A... 14.16A over the max current!

I now this is comming out in very few ocations, but: Its going to "toast" my Kid?

Sorry for my English

Thanks a lot, best wishes from Argentina.

Westbranch

welcome,  a little terminology first.... the KID is a Charge Controller not an inverter.  Inverters change DC to AC current. ;)

the Kid is limited to 30 amps output max , it will not output more than that. ???

If I understand you correctly you want to  are wanting to use that to limit the output to ?? AMPS...

You will need to install another KID for more  total Amps of output.

If you have a shading problem , it is possible to install more panels but the output will not exceed 30A.
The only way to get more power, Watts,  out of the KID is to go to 48Vots nominal...@ max 30A.
KID FW1811 560W >C&D 24V 900Ah AGM
CL150 29032 FW V.2126-NW2097-GP2133 175A E-Panel WBjr, 3Px4s 140W > 24V 900Ah AGM,
2 Cisco WRT54GL i/c DD-WRT Rtr, NetGr DS104Hub
Cotek ST1500 Inv  want a 24V  ROSIE Inverter
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West Chilcotin 1680+W to come

ClassicCrazy

I think it is no problem to put extra PV panels into the Kid - but as Westbranch said - the Kid controller will limit the output to 30 amps .

So yes you can use just one Kid but your output will be only 30 amps maximum.

Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

pmaril

Sorry, my mistake, I mean to say Charge-controller but my hand wrote "Inverter".

What I was looking for is to oversize-it, but not burn-it. I wrote also to support, and It`s OK to put a little more power, just have to be shure the Kid has sufficient airflow.

Quote from: Westbranch on April 21, 2017, 12:59:45 PM
welcome,  a little terminology first.... the KID is a Charge Controller not an inverter.  Inverters change DC to AC current. ;)

the Kid is limited to 30 amps output max , it will not output more than that. ???

If I understand you correctly you want to  are wanting to use that to limit the output to ?? AMPS...

You will need to install another KID for more  total Amps of output.

If you have a shading problem , it is possible to install more panels but the output will not exceed 30A.
The only way to get more power, Watts,  out of the KID is to go to 48Vots nominal...@ max 30A.

pmaril

That is exactly what I whant.

Dont need more power out of the kid, just a little more during the winter perhaps, but the client whats a more "balanced" system, in the visual aspect.

Quote from: ClassicCrazy on April 21, 2017, 10:51:39 PM
I think it is no problem to put extra PV panels into the Kid - but as Westbranch said - the Kid controller will limit the output to 30 amps .

So yes you can use just one Kid but your output will be only 30 amps maximum.

Larry

TomW

Quote from: pmaril on April 25, 2017, 11:00:51 AM
That is exactly what I whant.

Dont need more power out of the kid, just a little more during the winter perhaps, but the client whats a more "balanced" system, in the visual aspect.


Beyond cost dual controllers will also impose dual idle draw consumption.

If that is not an issue then 2X controllers should net you more raw power for cloud edge effect,  extra sunny days or cold weather when panels put out the most and might exceed the 30 amp threshold of one controller.

Would make panel upgrades easier, as well if you increase the production the controller is already there.

Seems an unnecessary add on just for aesthetics but the customer is always right, even when they ain't!


Just from here.

Tom
Do NOT mistake me for any kind of "expert".

( ͡° ͜ʖ ͡°)


24 Trina 310 watt modules, SMA SunnyBoy 7.7 KW Grid Tie inverter.

I thought that they were angels, but much to my surprise, We climbed aboard their starship and headed for the skies

Vic

When over-PVing CCs,   and the CC is Limiting current,   the PV input voltage  will increase (compared to what the PV Vin would be if the CC was not Limiting).

This increased Vin will reduce the efficiency of the MPPT CC,   at least a bit,   causing some increase in the operating temperature of the CC.   This is usually not a large issue,   but something that needs to be considered.

In addition,  when the CC is in a voltage regulating stage (Absorb,  Float,  or EQ),  the Vin will be higher (for the same output current from the CC),   than would be the case for a CC that is not over-PVed,   also increasing the CC temperature.

FWIW,  Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

ClassicCrazy

If your client would like much better monitoring via computer and android apps and the internet via  the Midnite web  based app then upgrading to the Classic charge controller is something to consider. Plus it can handle all the current too.

Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

tecnodave

Pmaril.

In my experience with both the Kid and the Classic 4 panels wired 2 in series will have a input voltage of 60-70 volts where 3 in series at 105-110 volts ,the configuration with higher input voltage will cause more heating even though the 4 panels have more total power, it's the higher voltage difference between battery out volts verses p.v. Input that causes more heating so I do not use 3 panels in series on 24 volt systems. Too much voltage difference.

For a while I had 2 classics side by side , one had 12 Sharp NE-170's wired 3 series 4 banks parallel , the other system had the same 12 Sharp NE-170's wired 2 in series 6 banks parallel (due to a longer run to the second array) , the system with 3 in series the fans were constantly running where the system with 2 in series the fans rarely ran. I felt that I was cooking my classic. I changed the configuration to be 2S 6P on system 1 and walla! cooler and fans not constantly running......especially when in a absorb whn the voltage rises due to the panels being loaded less,  lost a bit more power in the wire run (170 feet) but extended the service life of the Classic

I am very seriously over paneled for most situations but being so close to the Pacific Ocean, I do have some seriously cloudy/foggy weather sometimes for weeks!  Sunny days I'm in absorb by 9:30-10 am and floating way before noon.  Foggy days I always get to float even when I can't locate the sun position in the sky through the cloud cover. 

Lesson learned, try to keep the voltage ratio lower, system life will be longer!

Dave
#1 Classic 150 12 x Sharp NE-170, 2S6P, 24volt L-16 Rolls-Surette S-530, MS4024 & Cotek ,  C-40 dirv.cont. for hot water
#2 Classic 150 12 x Sharp NE-170, 2S6P, 24 volt L-16 Interstate,Brutus Inv.
#3 Kid/WBjr 4/6 Sanyo 200 watt multilayer 4/6 P
#4 Kid/WBjr 4/6 Sanyo 200 watt multilayer 2S 2/3 P

SM-Viper

I Just wanted to also say thanks to all for your replies here.  I have 2x2 panels with one Kid charging a 12v system and it works fine for me. The only thing I notice is the "over voltage" light comes on anytime I get a lot of sun in bulk while the Kid is limiting the output current.  This is great for cloudy days and in winter.

:) :)
12v Off grid backup system and "playground"
(4) 245 watt Solar World panels 2x2
(2) 6v Deka 215 AH golf cart batteries series
(1) Kid CC
(1) MNDC125 DC Disconnect, all 2/0 wire
wbjr and 500A shunt all breakers
(1) MNPV3 combiner box.

Sunshine

You will see the over voltage light come on when the kid is outputting its maximum 30 amps, even if your voltage is fine. This is normal and not a concern as long as you know that is why it is happening. Especially in areas of generically low solar performance, there is no harm over driving your PV amps a bit because you will rarely get peak performance from your panels anyway. Just be careful on the voltage side to stay within the limits of the controller, that is where you will do damage.

dgd

Hi Sunshine,
Who is actually doing development/support and firmware maintenance for the Kid? I have noticed Mario seems to have gone away as we never get responses from him concerning kid firmware features, some questions go back over well over a year now.
Thanks
Dgd
Classic 250, 150,  20 140w, 6 250w PVs, 2Kw turbine, MN ac Clipper, Epanel/MNdc, Trace SW3024E (1997), Century 1050Ah 24V FLA (1999). Arduino power monitoring and web server.  Off grid since 4/2000
West Auckland, New Zealand

WizBandit

Actually the KID's OVR LED is "OVER".
Over Voltage
Over Temperature
Over Amp Limit

The Kid flickers this LED as it limits the output between 30 and about 30.3 amps thus the flicker.  If you set the AMP LIMIT setting lower then it will flicker as it hits this limit and it steps over by about .3 to .5 amps and pulls back.

Over Voltage could be PV or Battery, the LCD will tell.

Over Temp usually means the KID is output amp limiting do to high heatsink temperature.  You can see the temp's in the KID's TEMP MENU under MISC.  Toggle between C & F using the SETUP BUTTON.

WizBandit

Quote from: dgd on June 02, 2017, 07:26:48 PM
Hi Sunshine,
Who is actually doing development/support and firmware maintenance for the Kid? I have noticed Mario seems to have gone away as we never get responses from him concerning kid firmware features, some questions go back over well over a year now.
Thanks
Dgd

Actually the KID is now "Feature Locked" with the final addition of Logging & Auto EQ.
Most of the SYNC Mode bugs have been fixed with the addition of some LED indicators, re-purposing the 2WK LED and ERROR LED.
Most if not all previous issues should now be fixed in FW 1856.

Mario is very involved with developing charge controller modules for the MNB17 Inverter system.  Any KID features questions can be directed to me.

ClassicCrazy

Quote from: WizBandit on June 02, 2017, 07:35:45 PM
Quote from: dgd on June 02, 2017, 07:26:48 PM
Hi Sunshine,
Who is actually doing development/support and firmware maintenance for the Kid? I have noticed Mario seems to have gone away as we never get responses from him concerning kid firmware features, some questions go back over well over a year now.
Thanks
Dgd

Actually the KID is now "Feature Locked" with the final addition of Logging & Auto EQ.
Most of the SYNC Mode bugs have been fixed with the addition of some LED indicators, re-purposing the 2WK LED and ERROR LED.
Most if not all previous issues should now be fixed in FW 1856.

Mario is very involved with developing charge controller modules for the MNB17 Inverter system.  Any KID features questions can be directed to me.

Wizbandit -
Do you have a document that identifies all the serial output available from the Kid ? I believe that additional output was asked for since 1820 firmware but not sure if anything was ever added ?

Thanks
Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable