[RE-wrenches] Problems with the Xantrex XW6048

[Mark Edmunds]

Hi Peter,

 

Erika is a good person to talk to about XW systems, she is the technical
product manager for the line. I will look into the history on your site
and someone will be in touch to give you a hand.

 

Regards,

 

Mark

 

Mark Edmunds

Xantrex Technology Inc.

 

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Peter
Parrish
Sent: Friday, November 28, 2008 10:23 AM
To: 'RE-wrenches'
Subject: [RE-wrenches] Problems with the Xantrex XW6048

 

I was hoping that I would not have to post the message, but I have been
unable to sort this problem on my own, and I am attempting to gather
information and advice from this august body.

 

We install about two grid-tied battery backup systems a year in the Los
Angeles basin and will probably continue to do so at this rate or
greater for the foreseeable future. I might add, that it is difficult
for us to support these installs and sales because of the added
complexity of the systems and the extra knowledge and terminology we
have to master. Those of you for whom the off-grid market is your
primary market, know this stuff backwards and forwards.

 

Having said that, the information I am looking for is any experiences
and advice that the wrenches may have and are willing to share with me
about the Xantrex 6048 (or similar) systems.

 

We purchased a XW6048 with two MPPT60-150 charge controllers. We also
have a System Control Panel and all four boxes are wired up using Cat5+
Ethernet cables (and terminations). The rest of the system consists of
30ea Sharp 142W modules and 8ea 8A8D 12V/225Ah batteries. The PV modules
are configured as six strings of five each and the batteries are
configured as two strings of four each. The module strings are combined
using fusible combiners of three strings each and fed into the charge
controllers separately. The batteries are hard wired using 2/0 cable
within the strings and 4/0 cable after combining. We are using SS
bolts/washers/nuts on lead terminals. The XW system and batteries are
located in a fully furnished basement in an air-conditioned home in Los
Angeles (i.e. the temperature in the basement varies no more than 65F to
80F.

 

Here's the problem: I monitor the system around local noon on a sunny
day, and expect to see the system producing in excess of 3.0 kW, with
the batteries fully charged. Here's what we see: the system is in sell
mode and he output power goes through an oscillation from about 2.15 kW
to 2.90 kW and back down again. The period of the oscillation is ~5 secs
on the rise and ~2 secs on the fall.

 

In consultation Xantrex, here is what we have done:

(1)   Fiddled with the GS voltage. Currently it is 53.0 V

(2)   Upgraded the firmware to Rev. 1.03.00

(3)   Fiddled with the max sell current, now 17.5 A

(4)   Fiddled with 2-stage vs 3-stage charge cycles. 3-stage on charge
controller and 2-stage on inverter/charger

(5)   Several other tweaks of no consequence

 

We have made a total of six trips to this customer after commissioning
the system, each time with a different set of suggested tweaks courtesy
of four different members of the technical support staff. One of the
trips was solely for the purpose of the firmware upgrade. All in all, I
have been working the problem now for over four months.

 

At this point in time, I have been unable to reach a live tech support
person after four tries spread out over two weeks. About five weeks ago,
one of the tech support individuals commented that this oscillation in
output power was a known phenomenon, but this was the same individual
that thought the problem would be fixed with the firmware upgrade. I'm
at my wits end. Leaving messages is a waste of my time. 

 

I apologize in advance for the long narration, but I was hoping to get
all the facts out there at once and minimize the amount of Q&As.

 

(1)   Has anyone seen this phenomenon in the XW systems?

(2)   If so, what was the fix?

(3)   What is the knowledge level and responsiveness of Xantrex Tech
support on this system? 

(4)   Is anyone experiencing a general decrease in the quality of Tech
Support at Xantrex?

(5)   To whom at Xantrex should I escalate this problem I am having? In
specific, I have spoken on two occasions with Erica Yedid, who I
understand is in charge of post-sales tech support for the SW system.

 

- Peter

Peter T. Parrish, Ph.D., President
California Solar Engineering, Inc.
820 Cynthia Ave., Los Angeles, CA 90065
Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885
CA Lic. 854779, NABCEP Cert. 031806-26
peter.parrish at calsolareng.com 

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