'Tweaks' Menu

[LostLoon]

Hi all,

I have a customer with a question. He is running a Classic 150 that ended up going into Hyper Voc before we thought it would in cold weather. We fixed his problem by using the input voltage offset (not sure if that is the exact wording) in the tweaks menu to trick the controller into firing up (we set it to the max, -5.0V), after which the voltage is well within operating range, and this fix has worked well enough that we decided to not swap it out for a Classic  200.

Should he switch that setting back when it warms up again? What does that setting do exactly? Just monitoring or is it affecting anything else in terms of performance? Are there any possible problems in running the controller all winter or all year with the offset maxed out? What was the purpose in including this feature?

Thanks!!

[Vic]

Hi LL,

In my opinion,  the Input and Bat voltage offsets are there to CALIBRATE the Classic to reality,  by using an accurate DMM/DVM.  I believe that you have uncalibrated the Classic,  by some amount.  I'd bet that as shipped that Classic 150 input voltage setting was within several tenths of a volt of being dead accurate.

Again,  my opinion,  there is a very good reason that the Claccic 150 was designed to stop operating at 150 volts input.  The Hyper VOC is a great addition,  where the CC does not get damaged at inputs within Hyper VOC.  There is ovbiously some allowable tolerance of just where the CC is permitted to operate near the low H VOC value.  Perhpas it is OK for the CC to operate above 150 V,  but I'd guess that this cannot be a good thing to do for extended periods of time  (read,  days).

Normally,  there is little power available when cold weather VOC is encountered,  but the beginning part of the wake-up and starting to make power might stress the CC.

Will let the MN team comment.  Personally,  if the string voltages are that high,  would consider switching to the mentioned Classic 200.  Whatta I know?  Vic

[boB]

The voltage offset tweak adjustment is to help the battery and/or PV input voltage to read a bit closer
to an accurate meter such as  Fluke meter.

The battery voltage is the most important one to be accurate and should be very close
as set from the factory with offset being 0.0   The PV input voltages will not be quite as accurate
as the battery voltage and doesn't have to be quite as close, BUT the input voltage
shouldn't really be more than +- 2.0 volts or so off because of the way the
Classic connects at Voc.  I'm not too worried about the input being maybe 2.0 volts
above absolute top end of 150.0 volts, but much more off than that can keep the Classic
from connecting properly and maybe even reduce its life with the Classic turning
on and off every day.

If the PV is cold enough that the input voltage starts out a few volts higher than 150V,
the sun should heat them up in not too long and should fall to 150V or below and then
turn on.

boB

[Halfcrazy]

In my opinion if the tweaks has to be run the hole 5vdc to "Trick" the Classic you are flirting with danger. It may last forever or may not but I would recommend a rewire or Classic 200.

Ryan