classic 150 ocp issue

[ripvansparky]

Hi folks, I have a classic 150 charging a 900ah bank at 12v. I had it powered by 4 evergreen 24v 215w panels hooked in series. It worked fine at that point. I then added two more panels (same) as two parallel strings of three panels. Thestring sizing tool said this would be near the safe limit but still ok. So I check it today around 1pm and it has 94 volts in, but is flashing between resting and ocp. I checked the basics hardcopy manual and the  CDrom manual and there is no mention of ocp. I assumed that it meant over current protection  so i changed the panels back to the original four with no change in status. I don't have cell service so I couldn't check online until the repeater got back, so I turned off the cc for awhile with no change, did a factory reset with no change, I verified the voltages with a voltmeter. Now that the repeater is back here I am but no answers to be found via search. So what gives?

[TomW]

Yeah, I would think "OCP" is over current protection but nothing in the manual about it.

My first thought is could it be shorted on the output somehow? Does it show the battery volts on the Display that is correct?

I have never seen this on mine and no "OCP" status in the manuals I have (online and CDROM).

I will poke Ryan and boB see if they can give better info than my guesses. They actually respond on weekends.

Tom

[ripvansparky]

Yeah, the battery volts is correct. I have restored everything to exactly as it was when it was working. Thanks

[boB]

Hi Rip.   Sorry about the OCP happening.

You are correct, there is nothing in the manual about OCP (Over Current Protection)
yet.  It's not supposed to OCP except when the battery side receives a large
current surge and even then, during very high surges.

OK, try this...  I assume you are in "Solar" tracking mode ??  If so, try
changing the mode to Legacy O&P mode and see if this gets it
going again.  Solar mode does a fast sweep and maybe it is
too fast now for some reason.

Weird thing is that it did work for you before.

Do you hear the relay click on and off now when you see OCP ?
I am wondering if it is actually turning on for a moment and then
triggering the OCP or is it not even turning on ?

Please let us know if legacy mode helps.

boB

[ripvansparky]

I left the cc off for the night and turned it on at 9, still no change. I just tried legacy mode, now it just says resting, but whenI switch back to solar, resting/ocp. So i did a factory reset with legacy and still just resting. I can't hear the relay while it is switching back and forth. In voltage is reading 129.3v aI and i am sure all the connections are solid. Funny thing is, my outback 2812 inverter was acting wonky for a couple days, sorted itself out, then this. I thinI may have added the panels on the last day of the weird inverter behavior. The 2812 would start charging for about 5 seconds then stop, then do it again a minute later. The mate (it's controller said communications error) but it fixed itself apparently. My eu3000is is racking up the hours doing charge duty now. 

[Vic]

Hi rip..

WOW!!  That is a very HIGH Vin,  especially on a probably fairly warm and sunny day.

What are the specs on the PV modules,  ie,  Vmp and Voc?

As you may know,  in cold or even cool weather,  usually early in the morning,  the voltage of the PVs rises,  This can exceed the rating of the Charge Controller and keep it from operating -- HyperVoc,  and could possibly damage the Classic,  if the voltage exceeds about 162 volts on a Classic 150 on a 12 V battery.

Sounds like the Classic is behaving like it believes that there is NO PV input voltage.

Furthermore,  even if the Classic will operate at high voltages of around 100 volts string Vmp,  the efficiency of the CC is reduced when using a 12 volt system,  as the CC needs to convert to such a low voltage -- the range from Vin to Vout is quite large.

This may not have a direct bearing on your current situation of the Classic not delivering power.

Have you used the MidNite String Sizer to determine the best PV string arrangement??   Thanks,   Vic

[ripvansparky]

Vmp is 29 and the Voc is 35.6. I knew about the inefficiency of the voltage difference, but I think I forgot about it in my quest for higher voltage to minimize drop in the transmission wires. I have run everything thru the string calc a few times and it says everything is good to a little ways below freezing, the string won't see those temps cause we will be out ta here before then! The 129ocv is the most I have seen, generally it is 125.

[Vic]

OK ripvan ..

Thanks for the info.  Good that the string sizer says it is  OK in your current environs.

And did you remove the front cover of the Classic and measure the voltage at the PV input terminals?  And have your checked all the connections for the entire PV input cabling?  All should be tight. Also a good idea to do the same for the CC output side all the way to the battery connections for tightness?  It is often a good idea to re-torque all connections in a day of two after installation (if possible) as things often conform and kinna cold-flow,  especially stranded wire.

I have nothing to offer re the CC not producing.  You could carefully try to measure Isc for the string.  By perhaps connecting your DMM to the PV input leads at night or early in the AM,  wait until after Sunrise  to see what current flows through the Dmm.

You would need to be very careful as your string voltage is high,  and could be lethal,  and trying to do this measurement when the sun is shining on the PV would cause an ARC at the point of contact.  So be very careful if you do attempt this.  You could just use the PV input breaker to make/break the connection,  but personally dislike to cycle breakers with current flowing if at all possible.

Anyway,  Good Luck,  Vic

[boB]

A VERY important question still remains unanswered for the inverter/charger AND the Classic CC...

What is the battery voltage ?   

And, what are the battery charging set point voltages ?

Are you using battery temperature compensation ?

Reason I ask this is that if the battery voltage is above the setpoint for
any reason, the CC and inverter/charger will have no reason to wake up.

It may be fine but we will need to rule that reason out for both chargers if
possible.

boB

[ripvansparky]

Hi Bob, the inverter is doing fine now, charging as well as inverting. It is set to trojan recommendations, can't remember exactly and not there at the moment. The cc was as well, until I did the reset which is now factory settings, they are just a tenth off of what trojan recommends if I remember correctly. The actual battery voltage has ranged from 11.6 Up to 13.6 since this has been happening. I  have a bogart shunt so i know they haven't been fully charged yet.

[ripvansparky]

Oh and not using temp compensation

[dgd]

Have you tried disconnecting the two additional PVs so that there is just the original four feeding the Classic - and see if the Classic returns to normal battery charging? as it was before you added the new PVs?
I have to agree with other replies concerning the high PV input voltage. any probable advantage you gain in losses in wiring are negated by the Classic's loss in efficiency in reducing 120V down to 12v.  I would just connect these PVs in parallel as they are about 36v at mpp.
36v to 12v would make a happier Classic.

dgd

[boB]

Hi Bob, the inverter is doing fine now, charging as well as inverting. It is set to trojan recommendations, can't remember exactly and not there at the moment. The cc was as well, until I did the reset which is now factory settings, they are just a tenth off of what trojan recommends if I remember correctly. The actual battery voltage has ranged from 11.6 Up to 13.6 since this has been happening. I  have a bogart shunt so i know they haven't been fully charged yet.

OK, sounds like battery voltage being too high may not be the problem.

Doing a factory setting reset (I assume you mean the Vulcan mind meld ?) should fix things
rather than make them worse.

If you have the MNGP/Remote (normal Classic, not a Lite), go to the main status screen and
hold down the Left-Arrow key  and tap the ENTER key.  This will bring up another screen
with a bunch of numbers on it with Input on the top-left and BATT on the top right.
Between those two titles may be a number.  If it would be zero (0) like shown on
the Local App, it may be blank.  Otherwise, please tell us the number that is shown
if not blank.

If it really is Blank (zero), there will be other reasons for it not waking up but since it
did not wake up and go back to Resting from a running condition, it may stay blank.

Another reason for it not waking up can be a bad connection or non-tight terminal
block screw.  But since you did have OCP's happening, I have a feeling that is not it.

Watch the input voltage (PV) closely and see if you can see it drop from that 129 Voc
reading momentarily.  If that was the case I would think that Legacy mode would
have made the Classic wake up again.

There IS a reason it is not waking up and we just have to narrow it down, hopefully.

boB

[boB]

Have you tried disconnecting the two additional PVs so that there is just the original four feeding the Classic - and see if the Classic returns to normal battery charging? as it was before you added the new PVs?

dgd

129 Volts Voc should not cause the Classic to just sit there and not wake up, but I suppose this
is worth a try.

It should be good up to 150 volts input, but that RFR on the secret status screen may help
narrow this down.  (I hope)

boB

[RossW]

129 Volts Voc should not cause the Classic to just sit there and not wake up, but I suppose this
is worth a try.

It should be good up to 150 volts input, but that RFR on the secret status screen may help
narrow this down.  (I hope)

I regularly see mine at 130Voc and saw 134.8Voc yesterday.
(operating voltage is usually around 105 but occasionally up to 129V)