[RE-wrenches] transformerless inverters and conductor colors

[Allen Frishman]

my 2 cents - As I understand it we need to consider both the Solar Panel and the inverter.

The use of a TL inverter requires the solar panels to be ungrounded which means that neither the Pos or Neg conductors from the solar panel are grounded and therefore no White wire.

We can also use a ungrounded panel on an inverter with a transformer but the color requirements are the same since there are no grounded conductors there are to be no white wires.
An example is the newer Sunpower Panels that are non polarized (neither pos or neg grounded) which can be used with standard transformer inverters. 

Make sense?


Al Frishman
AeonSolar
(917) 699-6641 - cell
(888) 460-2867
www.aeonsolar.com

On Sep 23, 2013, at 3:59 PM, Ray Walters wrote:

> Hi Marco;
> 
> Article 200.7 specifically prohibits using white wire for anything but grounded conductors.  This came up last year on a large project with an ungrounded array, that also had white incorrectly specified in the plans.  The appropriate colors would be red for positive, and black for negative. 
> R.Ray Walters
> CTO, Solarray, Inc
> Nabcep Certified PV Installer, 
> Licensed Master Electrician
> Solar Design Engineer
> 303 505-8760
> On 9/23/2013 1:27 PM, Marco Mangelsdorf wrote:
>> Hi all,
>>  
>> We’re doing more and more installs with TL inverters (SMA and P1).
>>  
>> I’m using double-insulated wire from the array string to the first enclosure, as in j-box, and then transitioning to standard THHN/THWN wire.
>>  
>> I recently purchased some of that #10 double-insulated wire, getting a spool of black and white.
>>  
>> Then after receiving the two spools it occurred to me: since the array is ungrounded, as far as there being no grounded conductor in the circuit, did I blow it by getting a spool of white wire?
>>  
>> What sayeth you all?  Can I not use that white wire in those array circuits for TL inverters?
>>  
>> Thanks,
>> marco
>>  
>> 
>> 
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