[RE-wrenches] Sunny Island Failure and various related issues

[william at millersolar.com]

Friends:

 

I have an existing service issue with a Sunny Island 4548 system shutting
down unexpectedly.  The system is off-grid with generator, two inverters, DC
coupled charging.  The batteries are a set of used Full River VRLA L-16s (3
strings of 8).  We tested the at-rest battery voltages and they were good
and consistent.

 

The system was running fine and then experienced some generator failures.
The inverters went into battery protect mode twice.  We found and repaired
the generator problem.  A few days later, about 10 minutes after I assured
the owner that all was well, the system shut down again.

 

We responded and found the generator was willing and able to start.  The
reason the system shut down is not apparent.  Here is what I have been told:

 

1.    The system reports the temp sensor lead has been unplugged.  There is
a temp sensor and it appears to be connected and in good condition.  SMA
repeatedly points to this as a contributory cause but I have trouble
figuring out how lack of a temp sensor cable could cause other than
inefficient charging.  We will replace the temp sensor tomorrow.

2.    The system does not have a battery shunt.  I am told this is also a
serious lack because the inverter "does not know what is going on with the
batteries".  I always thought the PV charge control and AC charge systems
operated independently and the inverter responded solely to battery voltage.
Maybe not so with the Sunny Island?  Could the inverter shut down
unexpectedly to protect batteries, even though voltage and SOC were at a
reasonable level at the time? The system does report marginal SOH.  We will
install a shunt tomorrow.

3.    Does anyone have any experience resolving mysterious shut-downs of
Sunny Island systems and have any insight they may provide?

4.    We download and read the SD data files in-house.  We have developed
some crude Excel macros that we use to paste the records into Excel and to
hide and reveal selected columns.  We find this tool to be very handy. I
know that SMA uses an Excel tool as well.  I have been meaning to ask if I
may have a copy but keep forgetting.  Do any of you analyze Sunny Island
data files in-house?  Do you have any tools or procedures that you could
share or describe?  

5.    The Sunny Island line is significantly lacking in BOS equipment.  They
do not provide any AC or DC OPCD equipment nor do they provide any type of
AC bypass.  After we realized this we proceeded to provide an Outback FX1000
cabinet with every Sunny Island install, neatly mated to the system with
gutter infrastructure.  We provide Square D panel boards with custom
interlock hardware for AC OPCD switching and bypassing.  The SMA phone
support technicians do not seem to understand the concepts behind this
application and are automatically dismissive of the outboard gear and blame
it for all problems.  Below is a link to another system we had to work with
SMA tech support on, and that we were never quite able to convince them that
we knew what we were doing: 

http://www.millersolar.com/MillerSolar/Portfolio/Commercial/RM/R_M.html

6.    I have had a difficult time working with most of the phone support
technicians at SMA.  From the very beginning most of them have presented an
attitude of arrogance and condescension.  I have had the quality of my work
called into question without any evidence to support that position.  I have
experienced long delays in receiving replies.  I have seen technicians
present incomplete diagnoses.  Fortunately Scoey Wildey of SMA was in town
while we were rebuilding a commercial Sunny Boy system and he came and
inspected our work and could vouch for it.  I have found one highly
professional, competent person at SMA who used to be in tech support who
will take my calls.  I'd like to give him credit but I don't want to share
him.  Also, Steve Jefferson and Scoey Wildey have intervened on my behalf on
a few occasions and I am grateful to them.

7.    I am wondering if anyone else has had a similar experience with SMA
tech support.  If it is not just me, maybe several of us could contact SMA
management and ask that they augment the training of the phone support crew.
I am sure they are capable of improving on their skills, both technical and
interpersonal.  We all know people in the industry that stand above the rest
in professional demeanor,  Rick Cullen, for example. I try to emulate his
always-available, always-helpful, open-minded approach to dealing with
people and challenges.  We should expect this of all manufacturer's
representatives.

 

Thanks to any of you who are willing to review my many questions and offer
suggestions or comments.

 

Sincerely,

 

William Miller

 

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