Mac,
Trace made both the SWI/PAR parallel stacking and a series
stacking cable. I don't know if stacking four units in
series/parallel is possible. I never investigated it, and the
manual (Rev. 4.01) doesn't address it. I suspect that it's not
possible, from this section on page 96:
The parallel stacking interface cable (SWI/PAR) simply
plugs into the stacking port on the left end of each
inverter and allows the two inverters to operate as a single
inverter. The interface method is based on the
series stacking system offered for the SW Series inverters since
their introduction for the North American
market. The parallel stacking system operates the inverters in
phase by having one of the inverters
operate as the MASTER and the other as a SLAVE. When an AC
source is connected, the MASTER first
synchronizes to the AC source, then connects to it and battery
charges. Since the SLAVE follows the
master and is set-up with a longer warm-up delay, the SLAVE
inverter is already synchronized when it
transfers the loads and starts battery charging. This allows
very smooth transitions from inverter mode to
charger mode.
I'd interpret this to mean that the SWI/PAR cable uses the only
stacking port available.
But the bigger issue is this: must you change it? It doesn't
matter that one pair works hard and the other rests unless the
hardworking pair aren't up to the job. Unless you have overload
shutdowns, there's no benefit to parallel stacking, and you're
messing with obsolete legacy hardware that's not supported and for
which parts and service will be difficult to obtain (good luck
finding a pair of SWI/PAR cables...). I'd advise against changing
the system configuration if there are no problems now - it sounds
like a solution in search of a problem.
Just my $.02...
Allan
Allan Sindelar
al...@positiveenergysolar.com
NABCEP Certified PV
Installation Professional
NABCEP Certified Technical Sales Professional
New Mexico EE98J Journeyman Electrician
Founder, Positive Energy, Inc.
A
Certified B CorporationTM
3209
Richards Lane
Santa Fe, New Mexico 87507
505 424-1112 office 780-2738 cell
www.positiveenergysolar.com
On 10/2/2013 9:01 AM, Mac Lewis wrote:
Hi wrenches,
I have some folks that I'm meeting in a couple of days that
have 4 Trace SW 5048 inverters. It's a very large, older
compound-style installation that the original installer has
bailed on. They have it set up so that there is a common
battery bank and each pair of series stacked inverters are
independently feeding 2 separate 120/240 busses. One of these
120/240 services gets utilized very heavily, and one isn't
really used at all. Is it possible with this type of
inverter, to have all four inverters feeding a common AC bus,
two feed Phase A and the other two feeding phase B?
I know that is possible to series stack and to parallel
stack this inverter, but can you do both at the same time?
If so, does anyone have a pin out to a parallel stacking
cable?
Thanks in advance
--
Mac Lewis
"Yo solo sé
que no sé nada." -Sócrates
_______________________________________________
List sponsored by Home Power magazine
List Address: RE-wrenches@lists.re-wrenches.org
Change email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out participant bios:
www.members.re-wrenches.org
|
_______________________________________________
List sponsored by Home Power magazine
List Address: RE-wrenches@lists.re-wrenches.org
Change email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out participant bios:
www.members.re-wrenches.org
