[RE-wrenches] Preventing 24/7 Transformer Losses

[Garrison Riegel]

Hello Wrenches,

 

In my area we end up installing a lot of systems on 240V 3Ph high leg
services.  To allow for more inverter options (like TL that require a
neutral) it seems like using a transformer would a good idea, but it is hard
to justify the losses under load and especially 24/7 losses required to keep
the core magnetized.

 

In a recent post on this same subject by Greg Smith from SMA he wrote, "If
you specify a transformer specifically for solar PV designs then the losses
are negligible."  The transformer tech people at the manufacturers I spoken
with have no idea what this means.  I emailed Greg for clarification but
have not yet had a reply.  On a recent project that needed a 30KVA
transformer the 24/7 losses were 200-300W depending on manufacturer, which
is not negligible, and in my area would require about 2kW of PV to offset.  

 

Does anyone know what Greg might be referring to?

 

What are folks doing to mitigate these losses?  Some kind of DC actuated
switch on the utility side of the transformer maybe?

 

Anything else to keep in mind when specifying a PV specific transformer?

 

Thank you for your thoughts.

 

Garrison

 

Garrison Riegel

Project Manager |  <http://www.solarserviceinc.com/> Solar Service Inc

[p] 847-677-0950 |  <mailto:garrison at solarserviceinc.com>
garrison at solarserviceinc.com

 

NABCEP Certified PV Installation ProfessionalT

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20141114/d85e44cd/attachment-0002.html>