input voltage too high

Discussion about the MX60 Charge Controller

Moderators: OutBack, OutBack Moderator Team

input voltage too high

Postby fishfartus on Mon Nov 21, 2011 5:51 am

I have an mx 60 charge controller with 4x 200w, 24V panels in series. On cold sunny days, my input voltage is 148V which shuts off my charge controller. I have had to bypass one of my panels in order to get any production at all. Is there a way to increase the shutoff voltage safely on the charge controller, or do I have to rewire my panels with a combiner box to keep my voltage within the tolerance of the charge controller, or is there some type of diode I can install to keep the voltage down a bit? Thanks...
fishfartus
Member
 
Posts: 6
Joined: Wed Nov 02, 2011 7:18 am
My RE system: Outback Flexmax 60, GTFX3524, step up transformer, 780W solar array, midnight solar e-panel

Re: input voltage too high

Postby SteveHiggins on Mon Nov 21, 2011 6:52 am

You will need to do something to get that voltage below 145Volts.

We shut off at 145 to protect the controller... I'm sure you'd rather that happen than to have to ship the controller back and forth to Outback for repairs...
Steve Higgins
Technical Services Director- Surrette Battery Company

\
SteveHiggins
OutBack Czar
 
Posts: 567
Joined: Thu Mar 03, 2005 3:43 pm
Location: Seattle

Re: input voltage too high

Postby fishfartus on Mon Nov 21, 2011 1:09 pm

woops... i am sorry my controllerer is a flexmax 60, not a mx60.... I added this post in the appropriate topic.
fishfartus
Member
 
Posts: 6
Joined: Wed Nov 02, 2011 7:18 am
My RE system: Outback Flexmax 60, GTFX3524, step up transformer, 780W solar array, midnight solar e-panel

Re: input voltage too high

Postby phonetic on Mon Dec 05, 2011 1:34 am

Was told the MX60 will switch off at 145 volts, and unoffically can survive 165 volts..is there any truth to this claim ?
phonetic
Member
 
Posts: 6
Joined: Thu Apr 28, 2011 9:32 pm
Location: Melbourne Australia
My RE system: 24 190W Tianwei MonoPVs, MidniteSolar Classic 150 & Lite Charge reg, 24V 1200AH Flooded Battery Bank, Outback VFX3024E Inverter Charger, 5kVA Autostart (Bio)Diesel Genset, 24/12V DC/DC Converter for Ham Radio Equipment, home brew 300W Wind turbine/shunt reg.

Re: input voltage too high

Postby Vic on Mon Dec 05, 2011 10:03 am

Hi phon,

Weather this voltage value is true or not (it depends upon whare it came from), why would you want to run this Warranty-Voiding experiment??

Know that this must be that you have a certain number of PV modules, and need the total power, and rewiring them (as should be done), may render one module short, or you might need to buy a couple more ... BUT, it seems to me, that it is similar to having a car with a specified maximum engine RPM, and wanting to know what would happen if that vaoue was exceeded by a bit. The answer is similar, you are on your own. YMMV etc.

You should NOT run the FM CC in this configuration. The PV array needs to be reconfigured to reduce the Vin. You may be able to run this way for some time without killing the CC, but you are on THIN ICE, BEWARE.

And there will probably not be a "surge" that would affect the CC. High Voc occurs, usually, on very cold mornings with faint sun. As the solar cells get higher angle sun, the solar heating reduces the Voc. Operating an <PPT CC at the very high end of its Vin spec can significantly reduce the efficiency -- this may not be too important to you, however. Good Lick, Vic
4/20/08: 18 Shell SQ 175-106 Vmpp, Stacked 5548 SW+, 1350 AH Surrette 4KS25's, MX-60, Kubota SQ-3250 25 KVA Polyphase Diesel genset. Thanks OutBack for this Forum + the great Support and Service.
Vic
OutBack Czar
 
Posts: 979
Joined: Sun Jul 09, 2006 12:56 pm
Location: San Joajuin County, CA

Re: input voltage too high

Postby Oliver on Fri Oct 18, 2013 11:07 am

Just a thought,
Why don't you wire two pair of panels in parallel then put the two pair in series. Your total Voc (open circuit voltage) into the Charge Controller will be somewhere in the 74 volt range; since your present configuration is yielding 37 volts per panel (145v/4=37v). You will end up with the same power, double the current, half the voltage leaving tons of room for your Charge Controller.
Using a zener diode (plus a dropping resistor) is a complete waste of energy and money. Just make sure any panels you put in parallel are very close in voltage; preferably < 0.6V (a diode drop) difference; measured.

Toenail
Oliver
Junior Member
 
Posts: 1
Joined: Thu Oct 03, 2013 1:34 pm
My RE system: VFX3524, FLEXmax 60, and MATE.

Re: input voltage too high

Postby chadjones99 on Fri Dec 19, 2014 4:17 am

I have the same issue and don’t want to rewire for a few volts over, I have a 48 volt system and my input voltage most of the time is 80 to 130 volts , now that its winter in the morning right as the sun hits the panels just for about a hour I lock out on over voltage. I switch from my MX60 which locked out at 141 I think to a flex 80 which locks out around 145 I think. I normal only go over by 2 or 3 volts do to the weather. I just want to know if there is a away to turn down the voltage input from the panels just a few volts, like a reastate but I can’t really find anything that will work.
chadjones99
Junior Member
 
Posts: 3
Joined: Mon Sep 01, 2014 8:47 am
My RE system: outback MX60 , FX 3648 inverter
8 230 watt sharp panels
3 rows of 8 -6volt golf cart battery's

Re: input voltage too high

Postby gww on Fri Dec 19, 2014 9:24 am

You might try a couple of big diodes but then you will lose the voltage at all times. One other thing to consider is the cc would run a bit more efficiant if your panel voltage was a bit closer to your battery voltage. If you rewire now you would be done forever. Just something to consider.
gww
gww
OutBack Guru
 
Posts: 344
Joined: Wed Sep 05, 2012 5:30 pm
My RE system: 1. installed
2. 5640 watts mx panels
3. 2 axial flux Hugh Piggot 500 watt turbines
5. 2 gvfx 3648 inverters
6. 1 mx 60 charge controller, 1 fm 80 and 1 morningstar ts60 pmw
7. outback mount, panel and sub panel
8. mate
9. 4 place hub
10. couple more cc, doc wattson
11. 800 ah, 48 volt fork truck battery

Re: input voltage too high

Postby Vic on Sun Dec 28, 2014 10:22 am

chadjones99 wrote:I have the same issue and don’t want to rewire for a few volts over, I have a 48 volt system and my input voltage most of the time is 80 to 130 volts , now that its winter in the morning right as the sun hits the panels just for about a hour I lock out on over voltage. I switch from my MX60 which locked out at 141 I think to a flex 80 which locks out around 145 I think. I normal only go over by 2 or 3 volts do to the weather. I just want to know if there is a away to turn down the voltage input from the panels just a few volts, like a reastate but I can’t really find anything that will work.


Hi chad ..,

So you have eight Sharp 230 Watt PVs, They are most probably not arranged in four strings of two, as this would result in a too-low input voltage to the CCs, especially in the Summer. So, we must assume that you are running two strings of four of these PVs.

In searching for Sharp 230 W PVs, do find one model that has a Vmp of 30 V, and a Voc of 37 volts. Do these Vmp and Voc numbers match the PVs that you are using?

Or, what is the Vmp, and Voc of your PVs?
How many PVs are in each string?
What is the coldest temperature for the location of this system?

Thanks! Vic
4/20/08: 18 Shell SQ 175-106 Vmpp, Stacked 5548 SW+, 1350 AH Surrette 4KS25's, MX-60, Kubota SQ-3250 25 KVA Polyphase Diesel genset. Thanks OutBack for this Forum + the great Support and Service.
Vic
OutBack Czar
 
Posts: 979
Joined: Sun Jul 09, 2006 12:56 pm
Location: San Joajuin County, CA


Return to MX60 Charge Controller

Who is online

Users browsing this forum: No registered users and 2 guests