relay clicking

[TomW]

elesaver;

The whole point of the clamp meter is it does not require opening the circuit to test it. No disconnection. As Resthome mentioned, just open the jaws and put them around the cable. It should read the amps and if it doesn't seem to work or reads negative amps one way, flip the meter over.  Unlike wired in meters you can't really hurt it by reversing the wire direction.

Important note:

only clamp around one cable or the net amps will always  be zero if you clamp over both plus and minus cables.

Pretty neat units.

Tom

[Westbranch]

[and if it doesn't seem to work /i]   there may also be a RESET or ZERO or CLEAR button to press as some (all?) have some residual memory   

[elesaver]

OK, then, I can give the amp meter a go.  I had looked up online and it showed taking the protective panel off the panel wiring on the back of the units and then use the leads. 

Another clue as to the problem...I am seeing "Got COMM?" from time to time.  It is a momentary screen.  Perhaps the classic is not communicating for some reason?

OK.  Out to test amps. :-)  I'll report later.

[ClassicCrazy]

And just to be sure - do you  have a clamp meter that will do DC also ?  Most models only do AC amps but there are meters that do both AC and DC.

Larry

[elesaver]

Yes, this is both an AC and a DC clamp meter.  It is a Southwire 21050T True RMS AC/DC Clamp Meter.  If I recall correctly, when I
tried putting the negative cable into the space of the clamp, I didn't get the numbers I thought I should have gotten so I figured that
I must be doing it wrong.  When the sun is bright tomorrow, I'll try again.  It has gotten a little late for good sun now.  Thanks for the help.

[ClassicCrazy]

As others have said - usually for the DC side it may show some current without being on anything  and there may be a button to zero it out . Then clamp it on just the positive , and then just the negative  . They should be close to the same .  You can check each string separate - and then do the main cable after the combiner - all the strings separately should add up pretty close to what you get coming out of the combiner box.

The short circuit current test would be if you had a single panel and took the positive and negative and short them together and put your clamp meter on the wire  and see what it says . But you really shouldn't need to do that unless you suspect for some reason one panel in a string  is acting goofy and want to find out which one.

You might want to test your meter on a DC circuit where you know the  current - just to make sure your meter is working right . Anything you can get to one of the two wires going to the device.

Larry

[Resthome]

A good place to test your meter is at the shunt for the WBjr. Clamp it around the negative going to the battery (only cable on that side of the shunt). It should match the reading on the Classic or the Local App for the WBjr.

[Resthome]

OK, then, I can give the amp meter a go.  I had looked up online and it showed taking the protective panel off the panel wiring on the back of the units and then use the leads. 

Another clue as to the problem...I am seeing "Got COMM?" from time to time.  It is a momentary screen.  Perhaps the classic is not communicating for some reason?

OK.  Out to test amps. :-)  I'll report later.

I think it is normal to see that Got Comm from time to time. At least I see it on an occasion. Just shouldn't be there all the time or it indicates a communication problem between MNGP and the Classic

[elesaver]

Mystery of clicking solved...the battery offset value was incorrect.  After measuring the battery voltage and correcting in the tweaks menu, the clicking stopped and things started working as they had been.  Someone had mentioned this may be the problem earlier.  We'll see tonight as the sun goes down if the clicking comes back.  If it does, I'll know this time it truly is low light. :-)

With the attempt to measure amps, my confusion remains supreme.  I have 4 strings of 2 panels each.  The panels are 36.73V nominal with 8.71 short circuit amps. 

Here's my confusion:  my classic never registers incoming voltage above 76V but sometimes it is showing above 50 amps.  (This does not account for tenths, etc. but to give the general reading.)  When I use the clamp meter on one of the strings, it reads 4 amps.  At the combiner box, each breaker reads 75.6V.  Inside, at the classic, the amps read 30.6.

When I clamp the wiring between the shunt and the battery, it reads about half the amount showing on the classic.  The negative wire coming out of the combiner box registers about half the amps showing on the classic screen also.

Is there any way to help clear my confusion with this? 

[ClassicCrazy]

Mystery of clicking solved...the battery offset value was incorrect.  After measuring the battery voltage and correcting in the tweaks menu, the clicking stopped and things started working as they had been.  Someone had mentioned this may be the problem earlier.  We'll see tonight as the sun goes down if the clicking comes back.  If it does, I'll know this time it truly is low light. :-)

With the attempt to measure amps, my confusion remains supreme.  I have 4 strings of 2 panels each.  The panels are 36.73V nominal with 8.71 short circuit amps. 

Here's my confusion:  my classic never registers incoming voltage above 76V but sometimes it is showing above 50 amps.  (This does not account for tenths, etc. but to give the general reading.)  When I use the clamp meter on one of the strings, it reads 4 amps.  At the combiner box, each breaker reads 75.6V.  Inside, at the classic, the amps read 30.6.

When I clamp the wiring between the shunt and the battery, it reads about half the amount showing on the classic.  The negative wire coming out of the combiner box registers about half the amps showing on the classic screen also.

Is there any way to help clear my confusion with this?

It would be good if you drew out a simple schematic with the voltage and amps at each point you check them.
You won't see as many amps input from the panels because higher voltage and lower amps . If you multiply the volts x amps you will get the Watts .
4 x 76 = 304 watts
304 x 4 strings = 1216 watts

  On the output of the Classic to the battery you could see more amps because lower voltage of the batteries output the amps will be greater . If you multiply the amps x volts at the output again you will get Watts . The Watts is comparable between input and output - but not the amps .

So if you batteries are 24v ( I forget what your system is )
1216 watts  divided by 24 v  = 50 amps

The Classic is not 100% efficient so it will never be exactly the same input and output .

I still don't follow where you checked the output amps - but not all of the output may go to the battery since some of it may be going to loads. The Whizbang system amps is the value actually going to the batteries. The Classic output may be different and a lot more if loads are on. Also even if no loads are on the Classic may be regulating the amps going to the batteries unless the charge state is Bulk when it sends all available power to the batteries. If the Classic is in Absorb or Float it is limiting the amps to the batteries.

Hope that makes some sense - might help if you draw out your system .

Larry

[Vic]

Mystery of clicking solved...the battery offset value was incorrect.  After measuring the battery voltage and correcting in the tweaks menu, the clicking stopped and things started working as they had been.  Someone had mentioned this may be the problem earlier.  We'll see tonight as the sun goes down if the clicking comes back.  If it does, I'll know this time it truly is low light. :-)

With the attempt to measure amps, my confusion remains supreme.  I have 4 strings of 2 panels each.  The panels are 36.73V nominal with 8.71 short circuit amps. 

Here's my confusion:  my classic never registers incoming voltage above 76V but sometimes it is showing above 50 amps.  (This does not account for tenths, etc. but to give the general reading.)  When I use the clamp meter on one of the strings, it reads 4 amps.  At the combiner box, each breaker reads 75.6V.  Inside, at the classic, the amps read 30.6.

When I clamp the wiring between the shunt and the battery, it reads about half the amount showing on the classic.  The negative wire coming out of the combiner box registers about half the amps showing on the classic screen also.

Is there any way to help clear my confusion with this?

Hi elesaver,

It is difficult for me to imagine how the Offset voltage could have been far off enough to cause the Classic to feel that the PV Vin was lower that Vbatt.
AND,  it is also difficult to see how that Offset voltage could have been very far off from the factory,  or what would have caused it to have changed ...

So,  your PVs are 72-cells,  and the Vmp is about 36.73,  believe that you are saying.  In warm weather the Vmp will be reduced,  especially in full sun,  as,  the STC Vmp is for PV cells at 25 C  -- room temperature.

Regarding each string of PVs having the same voltage,  this will occur,  when ALL of the Combiner breakers are closed  --  this connects the outputs of ALL  PVs together, both on the output busbar,  and at the input of each breaker from its respective PV module.

When zeroing your Clamp DC Ammeter,  the jaws of the meter need to be fully-closed,  and several feet away from any wiring/cables.  Many of these meters need to be Zeroed several times.  Keep pushing the Zero button until the display on the meter reads 00.00,  or 0.00 Amps.   And,  usually this zeroing will need to be re-done every minute or so.   You should monitor that the meter is still zeroed before making any reading (with the jaws closed,  and feet away from any wiring).

If your meter never zeroes,  or continues to have reading problems when measuring the negative lead from the Shunt to the battery,  then,  your meter may not be operating correctly.   You might try replacing the  meter's battery with a fresh one,  to see if that helps,  if you continue to have reading errors on the Clamp meter.

You have had some good advice already,  just my drive-by post.  Good Luck,   Vic

[elesaver]

I'd like to draw the system but I don't see any tools to allow that.

This clamp meter does not have a zero button as such.  It is new so the battery should be good although I can test it.  There is a "relative" button for zeroing capacitance and offset adjustment, according to the instruction booklet.

For further explanation about the absorb voltage setting:  if I don't have that voltage set high enough, the system goes to absorb (even if I have that time to 4 hours) and the batteries never come to full aH state.  Then, during the night, the battery voltage drops so that the inverter is showing low voltage by morning.  Someone on the Northern Arizona board who uses a forklift battery indicated that he had to do the same thing, I believe.  Just thought you'd like to know the reason for the higher setting.

I do check SG from time to time and it is good.  I only water the batteries every 4-5 weeks so I'm figuring that's good, too.

Thanks for all the help, everyone!

[Vic]

Hi elesaver,

Since,  I believe that you said that your meter reads True RMS,  it is probably better than my Clamp DC meter ...  on my meter,  the zero drifts,  and usually takes at least two successive zeroing attempts before it zeroes.

Think that all of these Clamp DC meters use a Hall-Effect DC current sensor,  and all of these  will have some zero-drift.  It is possible that your meter zeroes upon power-up.

This zero-drift could be called an offset ...

So,  when you power-up your meter,  and DC current mode is selected,  does the meter read 0.00 in the display?

On your Absorb voltage,  and time,  you said,
"   ...    if I don't have that voltage set high enough, the system goes to absorb (even if I have that time to 4 hours) and the batteries never come to full aH state.  Then, during the night, the battery voltage drops so that the inverter is showing low voltage by morning   ...   "

Just to try to be clear,  the Time setting in Classic,   is the maximum time that will be spent IN the Absorb stage  --  ie the time after the absorb  voltage has been reached (and maintained).  It is quite possible that you have your WBjr Shunt EA set to a too-high current value for your batteries,  and as a result,  the Vabs needs to be very high in order to more fully-charge the battery in the Absorb time that is set in the Classic.

Forklift batteries are tall,  some are quite tall,  which can mean that high Vabs settings might be needed to fully mix the electrolyte ...   Also,  almost all forklift batteries run fairly high SG electrolyte,  and this necessitates relatively high Vabs (but,  your almost EQ voltage setting for Absorb  does seem high).

Your reference to a "full aH state",  could mean that you might,  possibly,  be relying a bit too much of the WBjr's SOC readout for determining a true full charge.   Almost any battery Monitoring device  is really only a rough approximation of the actual SOC at any point in time (IMO).   As you do know  taking careful SG readings is by far the most accurate indication of actual SOC.

FWIW,   Vic

[elesaver]

Thanks for the tips, Vic.  When I first got the forklift batteries installed, I called the manufacturer and asked for EA value.  They said they had never been asked that before! Say, what?  They told me to set it at 28.7.  Anyway, I had remembered from the Northern Arizona forum, the rule of thumb was for 1-2% of aH capacity but since this was the manufacturer suggestion, I went with their number.  It worked for a while...which makes sense...but then, the aH and SG were off.  I had to do some "jockeying" to get things back to where the batteries were fully charged again during the day.  By jockeying, I mean to change the absorb time and the EA...EA set low and Abs time high.  After leveling out the battery, I set the EA at 9.3 (1% of aH capacity) and absorb time at 1:30.  That, too, was working until the relay clicking began.  We know the rest of the story from the postings above.  I may need to re-visit the EA value and lower it a bit more.  I think I can get it.

So, things are returning to "normal," whatever that means in this variable world of solar!  I'm remembering that during the summer with the high temps, I have to watch the batteries to make certain that they don't get overcooked, so to speak.  My loads are not extremely high...freezer and refrig only.  During the cold, I notice that it is a little harder to get the charging completed without making adjustments.

Thanks again.  I'll keep working at it.  I think that I will cover two of the panels one of these days and take measurements with the clamp meter.  I do believe they are all working properly but it would be smart to confirm rather than assume.

[elesaver]

Vic, I didn't address a couple of the other things you mentioned. 

Yes, the clamp meter does zero out but it doesn't hold zero for very long.  I'm figuring that's normal so I just keep zeroing until I see the 0.00 and then take a reading and push "hold."  Because the batteries are receiving some charging and the load is taking some of the current, I don't think I will ever get an accurate reading of the state of the state.  That's why I am going to test each of the 4 panel series sets.

And, yes, I am going to lower the EA to 5.0 amps today to see how things go.  The battery charge at sundown yesterday was 25.2.  At 2.3V per cell required, it should read 27.6.  I'm not allowing enough current to flow before it goes to float.  The change should correct things...I hope.